- Email: [email protected]
Repeat suicide attempts in Hong Kong community adolescents
ARTICLE IN PRESS
Social Science & Medicine 66 (2008) 232–241 www.elsevier.com/locate/socscimed
Repeat suicide attempts in Hong Kong community adolescents Joy P.S. Wonga, Sunita M. Stewartb,, Cindy Claassenb, Peter W.H. Leea, Uma Raob, T.H. Lama a
University of Hong Kong, Hong Kong UT Southwestern Medical Center at Dallas, Dallas, TX, USA
b
Available online 4 October 2007
Abstract It has been well documented that a history of suicide attempts confers risk for subsequent attempts; however, efforts to explain how variables may change after a previous attempt and in turn relate to future suicide attempts are rare in the literature. This study presents longitudinal data on adolescent suicide attempts in Hong Kong, and examines whether the data support the ‘‘crescendo’’ model to explain repeat suicide attempts. One thousand and ninety-nine community adolescents aged 12–18 years were evaluated at two assessment points 12 months apart (T1 and T2). The study assessed (1) risk factors at T1 for a suicide attempt between T1 and T2, (2) whether a suicide attempt during the 12 months prior to T1 predicted an attempt between the two assessment points, and (3) whether the indicators of distress worsened from T1 to T2 if an attempt had taken place in the interim. The results indicated that: (1) depressive symptoms, substance use, and suicidal ideation measured at T1 were independent predictors of a suicide attempt between T1 and T2; (2) suicide attempt in the year prior to T1 predicted suicide attempt between T1 and T2 after controlling for other predictors; and (3) suicide attempt between T1 and T2 was a predictive factor for a negative change from T1 to T2 in substance use, suicidal ideation, family relationships, depression, anxiety, and life stress. These findings are consistent with the ‘‘crescendo’’ model proposing that the risk of repeat attempts is enhanced following a previous suicide attempt. r 2007 Elsevier Ltd. All rights reserved. Keywords: Repeat suicide attempt; Crescendo model; Hong Kong; Adolescent
Introduction This study presents longitudinal data on repeat suicide attempts in a community sample of adolescents in Hong Kong, China. We examined our data in the light of the ‘‘crescendo’’ model of suicidality Corresponding author.
E-mail addresses: [email protected] (J.P.S. Wong), [email protected] (S.M. Stewart), [email protected] (C. Claassen), [email protected] (P.W.H. Lee), [email protected] (U. Rao), [email protected] (T.H. Lam). 0277-9536/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.socscimed.2007.08.031
(Clark, Gibbons, Fawcett, & Scheftner, 1989), which states that the chances of a repeat attempt are increased once a suicide attempt occurs. Specifically, we determined whether, among the adolescents in Hong Kong, a past attempt is a strong predictor of future attempts. We also examined whether the data were concordant with the hypothesis derived from the crescendo model, that an attempt exacerbates distress, which may then act as a further underlying contributor to future attempts. Two concerns guided this study. First, although suicide is a worldwide problem (Krug, Mercy,
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
Dahlberg, & Zwi, 2002), most empirical information about suicidal behaviors comes from mainstream western cultures. In order to develop generalizable theory, it is important to examine other cultures. Information about Hong Kong, arguably the most modernized city in Asia, may provide a preview of what is to follow in other urban areas in the region. Furthermore, information about Chinese groups in their home cultures may be relevant for Chinese immigrants who now reside in many western multicultural cities. A second concern is that although a suicide attempt increases the risk for completed suicide (Hawton & Fagg, 1988; Hawton, Harriss, & Zahl, 2006), and repeat attempters face an even greater risk (Zahl & Hawton, 2004), underlying factors that promote repeat attempts are not well understood. The Hong Kong context Suicide rates are rapidly rising in Hong Kong: there was a 50% increase in completed suicide from 1997 to 2003 (CSRP, 2005). The rates of suicide death per 100 000 young persons aged 15–19 were 13.0 in boys and 2.7 in girls (8.0 overall) in the United States (WHO Statistical Information System, 2005). In contrast, in Hong Kong the rates were lower overall (5.2), and more similar between boys (5.1) and girls (5.3) (WHO Statistical Information System, 2005). In 2001, 12 month suicide attempt rates among 14–18 year olds was 8.4% (8.3% in boys and 8.4% in girls) in Hong Kong (data for 14–18 year olds derived from Yip et al., 2004). The rate in the United States for this age group was 8.8% (11.2% in girls and 6.2% in boys) (Grunbaum et al., 2002). Thus, the attempt rates are similar in both cultures, though parallel to the completed suicide rate there is less of a discrepancy between genders in Hong Kong. In Hong Kong, the adolescent suicide studies have primarily investigated correlates rather than risk factors (Wong, Stewart, Ho, Rao, & Lam, 2005; Yip et al., 2004), with cross-sectional findings that resemble those typically found in western samples (e.g., King et al., 2001). While these studies represent significant preliminary work in Hong Kong, theory-driven prospective research is still lacking. There may be some important differences in relation to attitudes towards suicidality in western and Chinese cultures. The western perception of suicide as a reflection of distress is not shared by Chinese groups (Chiles et al., 1989), and there is
233
a less likelihood of family and friends rallying to the patient’s support following a suicide attempt. A suicide attempt is seen as a negation of the duties of an individual to his or her parents, violating the important value of filial piety, and resulting in stigma in the social community (Tzeng & Lipson, 2004). Repeat attempts: proposed models Although it is known that a history of suicide attempts confers risk for subsequent attempts, efforts to explain how variables may change after a previous attempt, and in turn relate to future suicide attempts, are rare in the literature. Clark et al. (1989) proposed two mechanisms that relate past to future suicide attempts. In the ‘‘trait’’ hypothesis, suicidal individuals continue to be at an equal risk for a future attempt whether a previous attempt has been made or not. In the ‘‘crescendo’’ hypothesis, risk for the past and the future suicide attempts is not stable. Following an attempt, an individual’s risk for future attempts becomes higher. Joiner et al. (2005) have proposed that, following an attempt, the mechanisms that normally act to prevent the individuals from making a suicide attempt (e.g., fear) become less effective because of habituation. There may also be negative effects of the act itself on the environment and on the individual, which promote future suicidal acts. One example of risk exacerbation occurs when a suicide attempt precipitates social distancing among individuals in the attempter’s support system, increasing isolation and distress experienced by the attempter. Relevant to the Chinese culture, discovery of a non-lethal suicide attempt may anger family members who do not see the act as a sign of distress but rather as ‘‘selfishness’’, and an indicator of disrespect for the family (Tzeng & Lipson, 2004). We explored the fit of our longitudinal data to the trait and the crescendo models presented in Fig. 1. Specifically, we reasoned that if repeat suicide acts were the result of persisting risk uninfluenced by a previous act (the trait model), the addition of information about a previous attempt to known risk factors would not enhance the prediction for another act. Such a model would be consistent with the solid line in the figure. In contrast, if a previous suicide attempt added independent prediction over and above the risk factors assessed at baseline, the
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
234
Methods Crescendo Hypothesis Level of Risk
Procedure Trait Hypothesis
Suicide Attempt
T1
Suicide Attempt Time
T2
Future
Fig. 1. Schematic presentation of risk in the trait and crescendo models.
data would be consistent with the dotted line depicting the crescendo model. We also hypothesized that there would be an increase in reported distress after the attempt in this social context. If this hypothesis is supported by the data, future suicidal acts may be promoted by the distress following an attempt.
This study is an extension of our cross-sectional survey examining suicidal behaviors in adolescents (Wong et al., 2005). Participants in the community sample at T1 and T2 were matched based on the unique identifiers that allowed tracking without revealing identity. Parents provided passive consent. On the day of the survey, students whose parents had not refused consent were informed of the purpose of the survey, of the right to refuse participation, and assured of the confidentiality of personal data. Students completed the questionnaire either in the classroom or assembly hall depending on the location provided by the school. A talk on stress and distress followed the survey. Students were encouraged to seek help if they experienced psychological symptoms, and provided referrals to mental health staff. This study was approved by the Ethics Committee of the Faculty of Medicine, University of Hong Kong. Participants
Research objectives Our study included participants who had made one or more previous suicide attempts at baseline, and some who made attempt(s) between the two time points of the study. We examined whether: 1. Prospectively obtained risk factors at baseline (T1) for suicide attempt by follow-up 12 months later (T2) were similar to those found in our cross-sectional study (Wong et al., 2005). We examined demographics (age, sex, parental education), individual psychopathology (depressive and anxiety symptoms, and substance use), environmental stress/protection (life stress and family relationships), suicidal ideation, and exposure to suicide attempts. 2. A suicide attempt prior to T1 was an independent predictor of a suicide attempt between T1 and the follow-up assessment 12 months later (T2), over and above the prediction by other risk factors at T1. 3. The occurrence of a suicide attempt between T1 and T2 predicted an increase in distress at T2 over the T1 assessment.
All the participants were Cantonese-speaking Hong Kong Chinese youth. Of the 2176 potential participants (61% boys and 39% girls) aged 12–18 at T1, we obtained complete data on 1747 (66% boys and 34% girls). Data for 1099 (66.7% boys and 33.3% girls) of the 1747 who provided complete questionnaires at T1 could be matched at T2 (attrition rate: 37%). The sex ratios for the original sample, T1, and T2 were not significantly different. The reasons for the loss of participants between T1 and T2 included that some students had dropped out of school by the following year (15% do so at the end of compulsory education across Hong Kong), had changed schools, were absent on the day of the survey, or had missing data that precluded a unique match. The final group consisted of 732 (66.7%) boys and 367 (33.3%) girls. Measures All the measures were administered in Chinese. The variables used in the present study were selected from a battery of survey instruments, many of which had been used in the previous local studies. Items which had not been previously used in the Hong Kong context with Chinese adolescents were
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
translated using a forward/backward translation procedure. Discrepancies between the original and the backward translations were examined and final wording achieved by discussion among bilingual professionals. The final version of the questionnaire was piloted in two classes outside the district (n ¼ 90), with minor changes and clarifications applied after the pilot. The following measures were obtained at both T1 and T2 unless otherwise noted: Demographics (obtained only at T1) Sex, age, and parental education were recorded. Parental education was reported as the average of mother’s and father’s years of education. Family structure: Participants indicated biological parents’ marital status. Responses were coded into intact married families or all the other categories. Psychopathology Depressive symptoms were assessed using the Center for Epidemiological Studies—Depression Scale (Radloff, 1977). The 20-item scale, designed to measure depressive symptoms in community samples, has been widely used in Hong Kong adolescents (e.g., Lam et al., 2004). We also calculated the number of participants that fell into the highest 10% of distribution, based on the findings that this demarcation on a depression scale reflects significant dysfunction, regardless of categorical diagnosis (Stewart, Lewinsohn, Lee, Ho, & Kennard, 2002). Cronbach’s alpha for the sample of this study at T1 was 0.85. Anxiety was measured using the 10 state items of the Chinese version of the State–Trait Anxiety Scale (Spielberger, Gorsuch, & Lushene, 1970). This scale has been previously translated and used in Hong Kong (Yung, Chui-Kam, French, & Chan, 2002). Cronbach’s alpha for the sample of this study at T1 was 0.85. The validity of the STAI is supported by correlations of 0.64, 0.43, and 0.35 with depressive symptoms, unpleasant family relationships, and life stress, respectively (Wong, Ho, & Lam., 2004). Substance use was assessed by questions in three categories of use: tobacco, alcohol, and other substance use (stimulants, inhalants, and cough syrup). Each participant was asked an initial question regarding the specific drug, which allowed categorization into never user, past user, recreational user, and current user. All the users then indicated how frequently they had used each substance in the last 30 days. Those who indicated
235
at least weekly use of any substance were coded as ‘‘users’’. Environmental stress/protection Life stress: Fourteen items relevant to the Hong Kong context were extracted from the Life Stress Inventory (Lewinsohn, Rohde, & Seeley, 1994). The participants indicated (yes/no) whether they had experienced specific events in the past 12 months. Examples of the events specified were: ‘‘Close relative or friend died’’, ‘‘Family’s financial situation got worse’’, and ‘‘More conflicts with friends’’. In addition a write-in item was also used. The number of events was totalled for a life stress score. Validity was supported by correlations of 0.35, 0.46, and 0.37 with anxiety symptoms, depressive symptoms, and poor family relationships, respectively (Wong et al., 2004). Family relationships were assessed by five items. Participants were asked to subjectively rate the quality of the general relationships with and between their parents, and between themselves and their siblings on a five-point Likert scale, and their overall family life on a four-point Likert scale. The scales were standardized and combined for analyses. Cronbach’s alpha for the study sample at T1 was 0.79. These questions have been used in previous adolescent studies in Hong Kong (Lam et al., 2004), and the initial validity is supported by correlations of 0.49 and 0.58 with anxiety and depressive symptoms, respectively (Wong et al., 2004). Suicide-related variables Suicidal ideation: We asked participants a single question from the Youth Risk Behavior Survey (Centers for Disease Control and Prevention, 1998): ‘‘During the past 12 months, did you ever seriously consider attempting suicide?’’ This question has been widely used in the West and previously used in Hong Kong adolescent samples (e.g., Lam et al., 2004). Exposure to suicide attempt by others was assessed by asking the participants if anyone they knew had made a suicide attempt in the previous 12 months. Those who indicated that they knew a suicide attempter were coded as ‘‘exposed’’ whereas those who indicated that they did not were coded as ‘‘unexposed’’. Suicide attempt in the previous 12 months was obtained using the question, ‘‘During the past 12 months, how many times did you actually attempt suicide?’’ with responses of 0, 1, and 2 times or more.
ARTICLE IN PRESS 236
J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
Any attempt prior to T1 was examined as a predictor of an attempt occurring in the months between T1 and T2. Twenty-four youth reported that they had made an attempt in the year prior to T1. Of these youth, 15 (62.5%) indicated that they had made one attempt, and 9 (37.5%) said they had made more than one attempt. A new attempt made between T1 and T2 and reported at the time of T2 assessment was considered to be an outcome event, and used to designate the participants as ‘‘suicide attempters’’ (n ¼ 49) or ‘‘non-attempters’’ (n ¼ 1050) during analyses examining the prospective predictive value of the risk factors reported at T1. Twenty-eight of these 49 (57.1%) indicated that they had made one attempt, and 21 (42.9%) said they had made more than a single attempt. To assess the third aim of our study, we examined whether an attempt made between the two surveys was associated with a worsening from baseline levels of potential risk factors at T2. Results Methods of analysis SPSS 11.0 was used for all the statistical analysis with the level of significance set at po0.05. To investigate our first aim, T1 variables were assessed for prediction to suicidal behavior in the year that intervened between the two surveys. In this first set of analyses, a MANOVA was used to identify the significant risk factors for continuous measures and logistic regression for categorical measures. Multiple logistic regression analyses were then used to prospectively determine the unique contribution of T1 characteristics in predicting a suicide attempt between T1 and T2. The first step of the regression analysis was conducted without inclusion of suicide attempt prior to T1 as a predictor for attempt between T1 and T2. The second step included suicide attempt prior to T1 as a predictor, and assessed our second aim. To investigate our third aim, the regression analyses were used to determine whether a suicide attempt occurring between the two surveys was associated with changes in the individual psychopathology, environmental stress/protection, and suicide ideation from T1 to T2. T1 measures of the same risk variables were included in modelling so that change over time would be assessed. In all the regression analyses, moderation of the findings by sex was tested by assessing the interac-
tion between each predictor and sex separately; only significant interactions are reported. Prospective modelling of suicidal behavior occurring between T1 and T2 The MANOVA (with sex and presence/absence of an attempt between the surveys as independent variables) was significant for attempt status (df ¼ 1038) (Wilk’s Lambda F ¼ 5.67, po0.001), for sex (F ¼ 10.95, po0.001), and for attempt status by sex (F ¼ 4.97, po0.001). T1 differences between those who did (n ¼ 49) and did not report a suicide attempt between T1 and T2 are shown in Table 1. The attempters were more likely to be girls, with higher T1 levels of depression, anxiety, stress, substance use, and suicidal ideation. They were also more likely to have made a pre-T1 suicide attempt. These results are consistent with our cross-sectional data (Wong et al., 2005). Girls reported more stressful events and higher levels of depressive symptoms than boys. They were more likely to report suicidal ideation in the year before, had been exposed to suicide attempts by others, and to have made an attempt before baseline. Girls who went on to attempt suicide showed more depressive symptoms at baseline, in comparison both to non-attempting girls and to boys who attempted suicide between T1 and T2. Suicide attempt prior to T1 and other risk factors: overlapping or independent variance? All T1 risk factors except pre-T1 suicide attempt were entered in the initial step of a multivariate regression analysis to determine their ability to predict subsequent suicidal behavior. The effect of a pre-T1 suicide attempt was assessed in the final step in the modelling. T1 levels of depression, substance use, and suicidal ideation were found to contribute significant independent risk for subsequent suicidal behavior in the whole group of participants. The effect of depression on the subsequent suicidal behavior was moderated by gender: depression was a significant independent risk factor for suicidal acts among girls, but not among boys. When pre-T1 suicidal behavior was added in the second set of the analysis (second column of numbers in Table 2), only T1 suicidal ideation and the presence of a preT1 suicide attempt were significant predictors of post-T1 suicidal behavior. Information about previous suicidal behavior was therefore independent
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
237
Table 1 Risk factors at T1 for a suicide attempt between T1 and T2 Risk factors at T1
Demographics Age Number of girls (%) Parental educationa Living in a single-parent family (%) Psychopathology Depressive symptomsb Depression score in top 10% n (%) Anxiety symptomsb Substance use (%)
Controls (no attempt between T1 and T2) Mean (SD)
Attempters (attempt between T1 p for effect o0.05 and T2) Mean (SD)
Boys (n ¼ 708)
Girls (n ¼ 342)
Boys (n ¼ 24)
Girls (n ¼ 25)
Total (n ¼ 49)
14.22 (1.22) – 3.79 (0.56)
15.22 14.55 (1.43) (1.57) – 342 (32.6) 3.67 (0.62) 3.75 (0.58)
15.09 (1.55) – 3.70 (0.71)
14.67 (1.31) 25 (51.0) O 3.69 (0.57)
66 (9.3)
45 (13.2)
111 (10.6)
14.25 (0.87) – 3.67 (0.42) 2 (8.3)
3 (12.0)
5 (10.2)
19.83 (7.19) 43 (6.1)
22.67 (8.42) 54 (15.8)
20.76 (7.72) 21.67 (6.41) 97 (9.2) 0
31.73 (8.30) 10 (40.0)
26.70 (8.92) 10 (20.4)
18.97 (4.63) 13 (1.8)
19.82 (5.56) 8 (2.3)
19.24 (4.97) 22.21 (6.19) 21 (2.0) 3 (12.5)
21.33 (4.80) 3 (12.0)
21.77 (5.49) 6 (12.2)
Total (n ¼ 1050)
Environmental stress/protective variables 1.64 (1.70) 2.09 (1.80) 1.79 (1.74) Life stressb Family relationshipsa
7.92 (1.62) 7.70 (1.68) 7.85 (1.64)
Suicide-related variables Suicidal ideation (%) 79 (11.2) Exposure to suicide attempt (%) 36 (5.1) Suicide attempt in 12 months 9 (1.3) prior to T1 (%)
56 (16.4) 39 (11.4) 7 (2.0)
135 (12.9) 75 (7.1) 16 (1.5)
Attempt status
Sex Attempt by sex O
O
O
O
O
O
O O
2.32 (1.91) 7.95 (1.69)
3.73 (2.16) 3.02 (2.14) O
9 (37.5) 1 (4.2) 2 (8.3)
10 (40.0) 4 (16.0) 6 (24.0)
O
7.68 (1.71) 7.81 (1.68)
19 (38.8) 5 (10.2) 8 (16.3)
O O
O O O
Note: The continuous variables were analyzed by an initial MANOVA which was significant (po0.001) for attempt status, sex, and attempt status by sex. Categorical variables were compared using chi-square analyses. a Higher scores indicate better parental education and family relationships. b Higher scores indicate higher levels of symptoms and stress.
of other risk factors in predicting a future suicide attempt. Change in risk factors from initial measure at T1 to postsuicide attempt at T2 The presence of an attempt between the two surveys was examined as a correlate of change in risk variables. Table 3 shows that suicide attempts occurring between T1 and T2 were significantly associated with increased substance use, suicidal ideation, depressive symptoms, anxiety, life stress, and poorer family relationships at T2 compared to T1. Sex by attempt status interactions were not significant, suggesting that there were similar
changes over time for the boys and the girls who made an attempt. Thus, at reevaluation after a suicide attempt, some of the factors that place the adolescent at risk for future suicidal behavior were exacerbated even further, showing increased strength compared to their baseline levels. Discussion Findings for this prospective study extend our cross-sectional results, suggesting that, in the absence of recent suicidal behavior among adolescents, depression, substance use, and suicidal ideation are important and independent predictors of subsequent suicidal behavior. When suicidal
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
238
Table 2 Unique contribution of risk factors at T1 for predicting suicide attempt between T1 and T2 Adjusted OR (95% CI)a for T1 predictors for all the participants, n ¼ 1099 Sex Depressive symptoms (per score) Anxiety symptoms (per score) Substance use (yes/ no) Life stress (per score) Suicidal ideation (yes/ no) Suicide attempt in 12 months prior to T1 (yes/no)
Adjusted OR (95% CI)a including history of suicide attempt in 12 months before T1, n ¼ 1099
1.49 (0.80–2.77) 1.46 (0.78–2.75) 1.05 (1.00–1.11)*,b 1.05 (0.99–1.10) 1.01 (0.94–1.08)
1.00 (0.93–1.08)
3.37 (1.15–9.83)*
2.96 (0.98–8.96)
1.07 (0.91–1.26) 2.80 (1.47–5.35)**
1.05 (0.89–1.25) 2.41 (1.22–4.77)*
–
3.85 (1.33–11.17)*
*po0.05, **po0.01. a The OR for risk factors are all adjusted for each other in the logistic regression model. b Sex moderated these results (OR for interaction of sex by depression ¼ 1.08, CI ¼ 1.00–1.16, po0.05) such that depression was a predictor for girls but not for boys at this step.
Table 3 The effect of a suicide attempt between T1 and T2 on the potential risk factors at T2 (controlling for the risk factor and the presence of suicide attempt at T1) Risk factors (dependent measure) at T2
Substance usea (yes ¼ 6; no ¼ 43) Suicidal ideationa (Yes ¼ 19; No ¼ 30) Family relationshipsc Depressive symptomsd Anxiety symptomsd Life stressd
Prediction offered by the presence of suicide attempt to change in risk factor from T1 Adjusted OR (95% CI); p 4.80 (2.00–11.54); po0.01 3.85 (2.09-7.10); po0.001 Bb; t; p 0.08;2.73; po0.01 0.09; 3.25; po0.005 0.10; 3.45; po0.005 0.10; 3.26; po0.005
a
Coded as present or absent. Standardized regression coefficient. c Higher scores indicate better family relationships. d Higher scores indicate higher levels of symptoms and stress. b
behavior in the previous year is present, however, suicidal ideation identifies those adolescents likely to repeat their self-destructive behavior better than
the other risk factors. Distress measures (substance use, suicidal ideation, poor family relationships, depression, anxiety, and life stress—some of which are also risk factors for suicidality) appear to be exacerbated compared to baseline when assessed following self-destructive acts, and may serve as a mechanism by which future suicide attempt is potentiated by past attempt. Typically, suicide attempt has been studied as an outcome—the hypothesized result of psychological, environmental, and other risk factors that trigger these behaviors (e.g., King et al., 2001; Yip et al., 2004). Yet it is also possible that suicidal acts themselves may impact the environment in which an adolescent functions. Substance use became non-significant as a risk factor for suicidal behaviors when previous suicide attempt was added in the model, likely because of its rarity in this Asian culture. There were only 27 youth who acknowledged using substance(s) (i.e., drugs, cigarettes, or alcohol) during the past 12 months; six of them attempted suicide in the time period of the study. Relatively high-frequency behaviors in the West may denote more pathology in Hong Kong where they are much less common, as suggested by our past findings in relation to other risk behaviors (Lam, Stewart, Ho, & Youth Sexuality Study Task Force, 2001). It is noteworthy that the number of suicide attempts from T1 to T2 nearly doubled. During the time period in between the two surveys, the singer, actor, and popular celebrity, Leslie Cheung, committed suicide. In the months that followed there was a sharp increase in the suicide deaths in Hong Kong that have been attributed to the sensational media coverage that followed (Yip et al., 2005). It is possible that the attempts also increased during the period that followed Leslie Cheung’s suicide. At T2, we identified 38 participants who reported a single suicide attempt and 27 who had made two or more attempts since the year prior to the baseline through the follow-up period. In post hoc analyses we considered whether they were different on the variables examined in this study. At T2, multiple attempters were significantly more depressed than single attempters (M, SD ¼ 33.16, 8.64 versus 23.22, 9.00, po0.001). They were also more anxious (25.48, 7.55 versus 21.34, 5.55, po0.05), reported more stressful events (3.93, 2.67 versus 1.76, 1.72, po0.001) and worse family relationships (6.57, 1.75 versus 7.64, 1.47, po0.01). They were more likely to
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
report substance abuse (OR ¼ 5.83, CI ¼ 1.40–24.25, po0.05) and suicidal ideation (OR ¼ 8.91, CI ¼ 2.86–27.74, po0.001) in the previous year. These findings provide some additional support to our hypothesis that suggests that each suicide attempt is associated with increased risk for further suicidal acts. Culture may moderate the findings that a suicide attempt is associated with increased stress in social and family interactions. In the West, Chiles et al. (1989) have described changes in the environment after an attempt as family members and close friends responded to the act with feelings of guilt and empathic support. Aldridge (1998) has likewise suggested that the ‘‘sick role’’ played by the suicidal individual may actually unite the family after a suicide attempt. Given the importance in Chinese culture of bringing honor to the family and avoiding disgrace (Ho, 1996), suicidal behaviors are likely to cause significant familial distress. It is notable that, in our study, family relationships deteriorated for suicide attempters from T1 to T2. Whether suicide attempts elicit different responses from social groups in the West than they do in Hong Kong remains a question for further cross-cultural study. The present study has both clinical and research implications. A suicide attempt may be accompanied by dynamic processes that lower the threshold for the next attempt. Previous attempt plus recent suicidal ideation are the two most salient risk factors. In the absence of information about a previous attempt, depressive symptoms, substance use, and suicidal ideation are important indicators of risk. Joiner et al. (2005) have proposed that, once an attempt is made, future attempts are disinhibited. Our study focuses instead on some of the critical change variables associated with a destructive spiral associated with the suicidal behavior, which include increased substance use, increased suicidal ideation, poorer family relationships, increased levels of depression and anxiety, and increased life stress. If the interventionists can target these factors, they may reduce the risk of repeated suicidality. The survey method over a relatively long period of time of 1 year does not allow us to determine the timing of the increased distress observed at T2. It is possible that increased distress preceded and precipitated the attempt rather than followed it. Although information about the complex temporal relationships is necessary to elaborate the model, at this point it is notable that distress was up a notch following a pre-T1 suicide attempt. It is quite
239
reasonable to assume that there could be multiple contributors to the distress, many of which could have preceded the post-T1 attempt. However, it is the presence (or persistence) of this distress following a pre-T1 suicide attempt that is at the crux of the model because of its possible influence over the future attempts. Future studies are necessary to elaborate the timing, the source, and the persistence of increased distress noted at T2. Repeated contacts over shorter periods of time, collecting both quantitative and qualitative information, are needed. It is also important to acknowledge that the trait and the crescendo models have been separated for simplicity. There are likely to be components of trait risk that apply even if a previous attempt enhances the risk for a future attempt. For example, a family history of suicidality and gender (acting through biological and psychosocial variables) are considered ‘‘immutable’’ risk factors. However, once an attempt has been made, other factors may also come into play, some as a result of the attempt. We are not aware of any completed suicides in our cohort in between the surveys. Prior to the T2 survey, school representatives were asked if any of their students had completed suicide after T1. No suicide deaths were reported. It is possible, but not likely, that older students who left or dropped out of school may have completed suicide without the knowledge of the school administration. However, Hong Kong remains a communal culture, and the death of a child who has been a student in the school is likely to be well known. The talk after the T1 survey might have had a salutary effect on some of the listeners and we do not know if it affected the results. However, there has been a general effort through the Department of Health in Hong Kong to increase awareness of depression and suicidality in the schools. This talk, therefore, would be only one component of an environment designed to enhance help-seeking among suicidal youth. Other limitations of our study include the exclusive use of self-report methods. There may be under-reporting of suicide attempts despite the anonymous nature of the survey. Our study was not powered to detect small effect sizes, even though the sample size is respectable for a study of suicide attempters. When attempters were broken down by sex, very small groups resulted with little power to detect differences. Other analyses, such as those examining the influence of drug use, also involved
ARTICLE IN PRESS 240
J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
small sample sizes and should be cautiously considered. We did not assess some important additional risk factors such as impulsivity and sexual abuse. Furthermore, some of the univariate predictors may be mediated by those that retain direct effects in the multivariate model. For example, stressors may exert their influence on suicidality by increasing depressive symptoms, or substance use may disinhibit and predispose towards suicidal ideation. Larger sample sizes and multiple data collection points are needed to investigate such mediational models. Conclusions Depressive symptoms, substance use, and suicidal ideation predicted a suicide attempt within the next 12 months in adolescents in Hong Kong. For youth who reported that they had not made a pre-T1 suicide attempt, substance use and suicidal ideation were strong predictors. When a recent suicide attempt was included in the model, only suicidal ideation and pre-T1 attempt were significant independent predictive factors for future attempt. Our findings support the model that proposes that a previous suicide attempt is an independent and powerful predictor of future attempts. Although the timing of this exacerbation cannot be determined, suicide attempt between T1 and T2 was associated with worse family relationships and increase in substance use, suicidal ideation, depression, anxiety, and life stress at T2. Repeat attempters may therefore be vulnerable to exacerbated risk factors that persist or are enhanced following a suicide attempt. Acknowledgments We thank Charles D. Spielberger and Paul Yung for granting permission to use the original and Chinese version of the State–Trait Anxiety Inventory. We thank Daniel Ho for his involvement in the fieldwork and data management, and Ben Cowling and Irene Wong for their statistical advice. We also thank the Healthy District Steering Committee, Central and Western District Board for financial support and, the Chairman, Mr. W.H. Lai for arranging social workers to follow up the students who were screened as at risk, participating schools in the district, parents, and students for their cooperation.
References Aldridge, D. (1998). The politics of symptoms and marital conflict. In Suicide: The tragedy of hopelessness. London and Philadelphia: Jessica Kingsley Publishers. Centers for Disease Control and Prevention (CDC). (1998). Youth risk behavior surveillance—United States, 1997. Morbidity and Mortality Weekly Report, 47(SS-3), 1–89. Chiles, J., Strosahl, K., Ping, Z. Y., Michael, M., Jamelka, R., Senn, B., et al. (1989). Depression, hopelessness and suicidal behavior in Chinese and American psychiatric patients. American Journal of Psychiatry, 146, 339–344. Clark, D. C., Gibbons, R. D., Fawcett, J., & Scheftner, W. A. (1989). What is the mechanism by which suicide attempts predispose to later suicide attempts? A mathematical model. Journal of Abnormal Psychology, 98(1), 42–49. CSRP. (2005). Statistics. Hong Kong Jockey Club Centre for Suicide Research and Prevention, University of Hong Kong, Hong Kong. URL: /http://csrp.hku.hk/WEB/eng/statistics. aspS [WWW page]. Grunbaum, J. A., Kann, L. K., Kinchen, S. A., Williams, B., Ross, J. G., Lowry, R., et al. (2002). Youth risk behavior surveillance—United States, 2001. CDC MMWR surveillance summaries (Vol. 51(SS04), pp. 1–64), June 28, 2002. URL: /http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5104a1.htmS [WWW page]. Hawton, K., & Fagg, J. (1988). Suicide and other causes of death, following attempted suicide. The British Journal of Psychiatry, 152, 359–366. Hawton, K., Harriss, L., & Zahl, D. (2006). Deaths from all causes in a long-term follow-up study of 11,583 deliberate self-harm patients. Psychological Medicine, 36(3), 397–405. Ho, D. Y. F. (1996). Filial piety and its psychological consequences. In M. H. Bond (Ed.), The handbook of Chinese psychology (pp. 155–165). New York: Oxford University Press. Joiner, T. E., Conwell, Y., Fitzpatrick, K. K., Witte, T. K., Schmidt, N. B., Berlim, M. T., et al. (2005). Four studies on how past and current suicidality relate even when ‘‘everything but the kitchen sink’’ is covaried. Journal of Abnormal Psychology, 114(2), 291–303. King, R. A., Schwab-Stone, M., Flisher, A. J., Greenwald, S., Kramer, R. A., Goodman, S. H., et al. (2001). Psychosocial and risk behavior correlates of youth suicide attempts and suicidal ideation. Journal of American Academy of Child and Adolescent Psychiatry, 40, 837–845. Krug, E. G., Mercy, J. A., Dahlberg, L. L., & Zwi, A. B. (2002). The first world report on violence and health. The Lancet, 5(360), 1083–1088. Lam, T. H., Stewart, S. M., Ho, L. M. & Youth Sexuality Study Task Force. (2001). Prevalence and correlates of smoking and sexual activity among Hong Kong adolescents. Journal of Adolescent Health, 29, 352–358. Lam, T. H., Stewart, S. M., Yip, P. S. F., Leung, G. M., Ho, L. M., Ho, D. S. Y., et al. (2004). Suicidality and cultural values among Hong Kong adolescents. Social Science & Medicine, 58, 487–498. Lewinsohn, P., Rohde, P., & Seeley, J. (1994). Psychosocial risk factors for future adolescent suicide attempts. Journal of Consulting and Clinical Psychology, 62, 297–305.
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241 Radloff, L. S. (1977). The CES-D scale: A self-report depression scale for research in the general population. Applied Psychological Measurement, 1, 385–401. Spielberger, C. D., Gorsuch, R. L., & Lushene, R. E. (1970). Manual for the state– trait anxiety inventory. Palo Alto, CA: Consulting Psychologists Press. Stewart, S. M., Lewinsohn, P., Lee, P. W. H., Ho, L. M., & Kennard, B. D. (2002). Symptoms patterns in depression and ‘‘subthreshold’’ depression among adolescents in Hong Kong and the United States. Journal of Cross-Cultural Psychology, 33, 559–576. Tzeng, W. C., & Lipson, J. G. (2004). The cultural context of suicide stigma in Taiwan. Qualitative Health Research, 14(3), 345–358. WHO Statistical Information System. (2005). WHO mortality database. URL: /http://www3.who.int/whosis/menu.cfm? path=whosis,mortS [WWW page]. Wong, J. P. S., Ho, S. Y., & Lam, T. H. (2004). Central and western district adolescent health survey 2002– 2003 full baseline report. Department of Community Medicine, The University of Hong Kong.
241
Wong, J. P. S., Stewart, S. M., Ho, S. Y., Rao, U., & Lam, T. H. (2005). Exposure to suicide and suicidal behaviors among Hong Kong adolescents. Social Science & Medicine, 61, 591–599. Yip, P. S. F., Fu, K. W., Yang, K. C. T., Ip, B. Y. T., Chan, C. L. W., Chen, E. Y. H., et al. (2005). The effects of a celebrity suicide on suicide rates in Hong Kong. Journal of Affective Disorders, 93, 245–252. Yip, P. S. F., Liu, K. Y., Lam, T. H., Stewart, S. M., Chen, E., & Fan, S. (2004). Suicidality among high school students in Hong Kong, SAR. Suicide and Life-Threatening Behavior, 34(3), 284–297. Yung, P. M. B., Chui-Kam, S., French, P., & Chan, T. M. (2002). A controlled trail of music and pre-operative anxiety in Chinese men undergoing transurethral resection of the prostate. Journal of Advanced Nursing, 39, 532–539. Zahl, D. L., & Hawton, K. (2004). Repetition of deliberate selfharm and subsequent suicide risk: Long-term follow-up study of 11,583 patients. The British Journal of Psychiatry, 185, 70–75.
Social Science & Medicine 66 (2008) 232–241 www.elsevier.com/locate/socscimed
Repeat suicide attempts in Hong Kong community adolescents Joy P.S. Wonga, Sunita M. Stewartb,, Cindy Claassenb, Peter W.H. Leea, Uma Raob, T.H. Lama a
University of Hong Kong, Hong Kong UT Southwestern Medical Center at Dallas, Dallas, TX, USA
b
Available online 4 October 2007
Abstract It has been well documented that a history of suicide attempts confers risk for subsequent attempts; however, efforts to explain how variables may change after a previous attempt and in turn relate to future suicide attempts are rare in the literature. This study presents longitudinal data on adolescent suicide attempts in Hong Kong, and examines whether the data support the ‘‘crescendo’’ model to explain repeat suicide attempts. One thousand and ninety-nine community adolescents aged 12–18 years were evaluated at two assessment points 12 months apart (T1 and T2). The study assessed (1) risk factors at T1 for a suicide attempt between T1 and T2, (2) whether a suicide attempt during the 12 months prior to T1 predicted an attempt between the two assessment points, and (3) whether the indicators of distress worsened from T1 to T2 if an attempt had taken place in the interim. The results indicated that: (1) depressive symptoms, substance use, and suicidal ideation measured at T1 were independent predictors of a suicide attempt between T1 and T2; (2) suicide attempt in the year prior to T1 predicted suicide attempt between T1 and T2 after controlling for other predictors; and (3) suicide attempt between T1 and T2 was a predictive factor for a negative change from T1 to T2 in substance use, suicidal ideation, family relationships, depression, anxiety, and life stress. These findings are consistent with the ‘‘crescendo’’ model proposing that the risk of repeat attempts is enhanced following a previous suicide attempt. r 2007 Elsevier Ltd. All rights reserved. Keywords: Repeat suicide attempt; Crescendo model; Hong Kong; Adolescent
Introduction This study presents longitudinal data on repeat suicide attempts in a community sample of adolescents in Hong Kong, China. We examined our data in the light of the ‘‘crescendo’’ model of suicidality Corresponding author.
E-mail addresses: [email protected] (J.P.S. Wong), [email protected] (S.M. Stewart), [email protected] (C. Claassen), [email protected] (P.W.H. Lee), [email protected] (U. Rao), [email protected] (T.H. Lam). 0277-9536/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.socscimed.2007.08.031
(Clark, Gibbons, Fawcett, & Scheftner, 1989), which states that the chances of a repeat attempt are increased once a suicide attempt occurs. Specifically, we determined whether, among the adolescents in Hong Kong, a past attempt is a strong predictor of future attempts. We also examined whether the data were concordant with the hypothesis derived from the crescendo model, that an attempt exacerbates distress, which may then act as a further underlying contributor to future attempts. Two concerns guided this study. First, although suicide is a worldwide problem (Krug, Mercy,
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
Dahlberg, & Zwi, 2002), most empirical information about suicidal behaviors comes from mainstream western cultures. In order to develop generalizable theory, it is important to examine other cultures. Information about Hong Kong, arguably the most modernized city in Asia, may provide a preview of what is to follow in other urban areas in the region. Furthermore, information about Chinese groups in their home cultures may be relevant for Chinese immigrants who now reside in many western multicultural cities. A second concern is that although a suicide attempt increases the risk for completed suicide (Hawton & Fagg, 1988; Hawton, Harriss, & Zahl, 2006), and repeat attempters face an even greater risk (Zahl & Hawton, 2004), underlying factors that promote repeat attempts are not well understood. The Hong Kong context Suicide rates are rapidly rising in Hong Kong: there was a 50% increase in completed suicide from 1997 to 2003 (CSRP, 2005). The rates of suicide death per 100 000 young persons aged 15–19 were 13.0 in boys and 2.7 in girls (8.0 overall) in the United States (WHO Statistical Information System, 2005). In contrast, in Hong Kong the rates were lower overall (5.2), and more similar between boys (5.1) and girls (5.3) (WHO Statistical Information System, 2005). In 2001, 12 month suicide attempt rates among 14–18 year olds was 8.4% (8.3% in boys and 8.4% in girls) in Hong Kong (data for 14–18 year olds derived from Yip et al., 2004). The rate in the United States for this age group was 8.8% (11.2% in girls and 6.2% in boys) (Grunbaum et al., 2002). Thus, the attempt rates are similar in both cultures, though parallel to the completed suicide rate there is less of a discrepancy between genders in Hong Kong. In Hong Kong, the adolescent suicide studies have primarily investigated correlates rather than risk factors (Wong, Stewart, Ho, Rao, & Lam, 2005; Yip et al., 2004), with cross-sectional findings that resemble those typically found in western samples (e.g., King et al., 2001). While these studies represent significant preliminary work in Hong Kong, theory-driven prospective research is still lacking. There may be some important differences in relation to attitudes towards suicidality in western and Chinese cultures. The western perception of suicide as a reflection of distress is not shared by Chinese groups (Chiles et al., 1989), and there is
233
a less likelihood of family and friends rallying to the patient’s support following a suicide attempt. A suicide attempt is seen as a negation of the duties of an individual to his or her parents, violating the important value of filial piety, and resulting in stigma in the social community (Tzeng & Lipson, 2004). Repeat attempts: proposed models Although it is known that a history of suicide attempts confers risk for subsequent attempts, efforts to explain how variables may change after a previous attempt, and in turn relate to future suicide attempts, are rare in the literature. Clark et al. (1989) proposed two mechanisms that relate past to future suicide attempts. In the ‘‘trait’’ hypothesis, suicidal individuals continue to be at an equal risk for a future attempt whether a previous attempt has been made or not. In the ‘‘crescendo’’ hypothesis, risk for the past and the future suicide attempts is not stable. Following an attempt, an individual’s risk for future attempts becomes higher. Joiner et al. (2005) have proposed that, following an attempt, the mechanisms that normally act to prevent the individuals from making a suicide attempt (e.g., fear) become less effective because of habituation. There may also be negative effects of the act itself on the environment and on the individual, which promote future suicidal acts. One example of risk exacerbation occurs when a suicide attempt precipitates social distancing among individuals in the attempter’s support system, increasing isolation and distress experienced by the attempter. Relevant to the Chinese culture, discovery of a non-lethal suicide attempt may anger family members who do not see the act as a sign of distress but rather as ‘‘selfishness’’, and an indicator of disrespect for the family (Tzeng & Lipson, 2004). We explored the fit of our longitudinal data to the trait and the crescendo models presented in Fig. 1. Specifically, we reasoned that if repeat suicide acts were the result of persisting risk uninfluenced by a previous act (the trait model), the addition of information about a previous attempt to known risk factors would not enhance the prediction for another act. Such a model would be consistent with the solid line in the figure. In contrast, if a previous suicide attempt added independent prediction over and above the risk factors assessed at baseline, the
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
234
Methods Crescendo Hypothesis Level of Risk
Procedure Trait Hypothesis
Suicide Attempt
T1
Suicide Attempt Time
T2
Future
Fig. 1. Schematic presentation of risk in the trait and crescendo models.
data would be consistent with the dotted line depicting the crescendo model. We also hypothesized that there would be an increase in reported distress after the attempt in this social context. If this hypothesis is supported by the data, future suicidal acts may be promoted by the distress following an attempt.
This study is an extension of our cross-sectional survey examining suicidal behaviors in adolescents (Wong et al., 2005). Participants in the community sample at T1 and T2 were matched based on the unique identifiers that allowed tracking without revealing identity. Parents provided passive consent. On the day of the survey, students whose parents had not refused consent were informed of the purpose of the survey, of the right to refuse participation, and assured of the confidentiality of personal data. Students completed the questionnaire either in the classroom or assembly hall depending on the location provided by the school. A talk on stress and distress followed the survey. Students were encouraged to seek help if they experienced psychological symptoms, and provided referrals to mental health staff. This study was approved by the Ethics Committee of the Faculty of Medicine, University of Hong Kong. Participants
Research objectives Our study included participants who had made one or more previous suicide attempts at baseline, and some who made attempt(s) between the two time points of the study. We examined whether: 1. Prospectively obtained risk factors at baseline (T1) for suicide attempt by follow-up 12 months later (T2) were similar to those found in our cross-sectional study (Wong et al., 2005). We examined demographics (age, sex, parental education), individual psychopathology (depressive and anxiety symptoms, and substance use), environmental stress/protection (life stress and family relationships), suicidal ideation, and exposure to suicide attempts. 2. A suicide attempt prior to T1 was an independent predictor of a suicide attempt between T1 and the follow-up assessment 12 months later (T2), over and above the prediction by other risk factors at T1. 3. The occurrence of a suicide attempt between T1 and T2 predicted an increase in distress at T2 over the T1 assessment.
All the participants were Cantonese-speaking Hong Kong Chinese youth. Of the 2176 potential participants (61% boys and 39% girls) aged 12–18 at T1, we obtained complete data on 1747 (66% boys and 34% girls). Data for 1099 (66.7% boys and 33.3% girls) of the 1747 who provided complete questionnaires at T1 could be matched at T2 (attrition rate: 37%). The sex ratios for the original sample, T1, and T2 were not significantly different. The reasons for the loss of participants between T1 and T2 included that some students had dropped out of school by the following year (15% do so at the end of compulsory education across Hong Kong), had changed schools, were absent on the day of the survey, or had missing data that precluded a unique match. The final group consisted of 732 (66.7%) boys and 367 (33.3%) girls. Measures All the measures were administered in Chinese. The variables used in the present study were selected from a battery of survey instruments, many of which had been used in the previous local studies. Items which had not been previously used in the Hong Kong context with Chinese adolescents were
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
translated using a forward/backward translation procedure. Discrepancies between the original and the backward translations were examined and final wording achieved by discussion among bilingual professionals. The final version of the questionnaire was piloted in two classes outside the district (n ¼ 90), with minor changes and clarifications applied after the pilot. The following measures were obtained at both T1 and T2 unless otherwise noted: Demographics (obtained only at T1) Sex, age, and parental education were recorded. Parental education was reported as the average of mother’s and father’s years of education. Family structure: Participants indicated biological parents’ marital status. Responses were coded into intact married families or all the other categories. Psychopathology Depressive symptoms were assessed using the Center for Epidemiological Studies—Depression Scale (Radloff, 1977). The 20-item scale, designed to measure depressive symptoms in community samples, has been widely used in Hong Kong adolescents (e.g., Lam et al., 2004). We also calculated the number of participants that fell into the highest 10% of distribution, based on the findings that this demarcation on a depression scale reflects significant dysfunction, regardless of categorical diagnosis (Stewart, Lewinsohn, Lee, Ho, & Kennard, 2002). Cronbach’s alpha for the sample of this study at T1 was 0.85. Anxiety was measured using the 10 state items of the Chinese version of the State–Trait Anxiety Scale (Spielberger, Gorsuch, & Lushene, 1970). This scale has been previously translated and used in Hong Kong (Yung, Chui-Kam, French, & Chan, 2002). Cronbach’s alpha for the sample of this study at T1 was 0.85. The validity of the STAI is supported by correlations of 0.64, 0.43, and 0.35 with depressive symptoms, unpleasant family relationships, and life stress, respectively (Wong, Ho, & Lam., 2004). Substance use was assessed by questions in three categories of use: tobacco, alcohol, and other substance use (stimulants, inhalants, and cough syrup). Each participant was asked an initial question regarding the specific drug, which allowed categorization into never user, past user, recreational user, and current user. All the users then indicated how frequently they had used each substance in the last 30 days. Those who indicated
235
at least weekly use of any substance were coded as ‘‘users’’. Environmental stress/protection Life stress: Fourteen items relevant to the Hong Kong context were extracted from the Life Stress Inventory (Lewinsohn, Rohde, & Seeley, 1994). The participants indicated (yes/no) whether they had experienced specific events in the past 12 months. Examples of the events specified were: ‘‘Close relative or friend died’’, ‘‘Family’s financial situation got worse’’, and ‘‘More conflicts with friends’’. In addition a write-in item was also used. The number of events was totalled for a life stress score. Validity was supported by correlations of 0.35, 0.46, and 0.37 with anxiety symptoms, depressive symptoms, and poor family relationships, respectively (Wong et al., 2004). Family relationships were assessed by five items. Participants were asked to subjectively rate the quality of the general relationships with and between their parents, and between themselves and their siblings on a five-point Likert scale, and their overall family life on a four-point Likert scale. The scales were standardized and combined for analyses. Cronbach’s alpha for the study sample at T1 was 0.79. These questions have been used in previous adolescent studies in Hong Kong (Lam et al., 2004), and the initial validity is supported by correlations of 0.49 and 0.58 with anxiety and depressive symptoms, respectively (Wong et al., 2004). Suicide-related variables Suicidal ideation: We asked participants a single question from the Youth Risk Behavior Survey (Centers for Disease Control and Prevention, 1998): ‘‘During the past 12 months, did you ever seriously consider attempting suicide?’’ This question has been widely used in the West and previously used in Hong Kong adolescent samples (e.g., Lam et al., 2004). Exposure to suicide attempt by others was assessed by asking the participants if anyone they knew had made a suicide attempt in the previous 12 months. Those who indicated that they knew a suicide attempter were coded as ‘‘exposed’’ whereas those who indicated that they did not were coded as ‘‘unexposed’’. Suicide attempt in the previous 12 months was obtained using the question, ‘‘During the past 12 months, how many times did you actually attempt suicide?’’ with responses of 0, 1, and 2 times or more.
ARTICLE IN PRESS 236
J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
Any attempt prior to T1 was examined as a predictor of an attempt occurring in the months between T1 and T2. Twenty-four youth reported that they had made an attempt in the year prior to T1. Of these youth, 15 (62.5%) indicated that they had made one attempt, and 9 (37.5%) said they had made more than one attempt. A new attempt made between T1 and T2 and reported at the time of T2 assessment was considered to be an outcome event, and used to designate the participants as ‘‘suicide attempters’’ (n ¼ 49) or ‘‘non-attempters’’ (n ¼ 1050) during analyses examining the prospective predictive value of the risk factors reported at T1. Twenty-eight of these 49 (57.1%) indicated that they had made one attempt, and 21 (42.9%) said they had made more than a single attempt. To assess the third aim of our study, we examined whether an attempt made between the two surveys was associated with a worsening from baseline levels of potential risk factors at T2. Results Methods of analysis SPSS 11.0 was used for all the statistical analysis with the level of significance set at po0.05. To investigate our first aim, T1 variables were assessed for prediction to suicidal behavior in the year that intervened between the two surveys. In this first set of analyses, a MANOVA was used to identify the significant risk factors for continuous measures and logistic regression for categorical measures. Multiple logistic regression analyses were then used to prospectively determine the unique contribution of T1 characteristics in predicting a suicide attempt between T1 and T2. The first step of the regression analysis was conducted without inclusion of suicide attempt prior to T1 as a predictor for attempt between T1 and T2. The second step included suicide attempt prior to T1 as a predictor, and assessed our second aim. To investigate our third aim, the regression analyses were used to determine whether a suicide attempt occurring between the two surveys was associated with changes in the individual psychopathology, environmental stress/protection, and suicide ideation from T1 to T2. T1 measures of the same risk variables were included in modelling so that change over time would be assessed. In all the regression analyses, moderation of the findings by sex was tested by assessing the interac-
tion between each predictor and sex separately; only significant interactions are reported. Prospective modelling of suicidal behavior occurring between T1 and T2 The MANOVA (with sex and presence/absence of an attempt between the surveys as independent variables) was significant for attempt status (df ¼ 1038) (Wilk’s Lambda F ¼ 5.67, po0.001), for sex (F ¼ 10.95, po0.001), and for attempt status by sex (F ¼ 4.97, po0.001). T1 differences between those who did (n ¼ 49) and did not report a suicide attempt between T1 and T2 are shown in Table 1. The attempters were more likely to be girls, with higher T1 levels of depression, anxiety, stress, substance use, and suicidal ideation. They were also more likely to have made a pre-T1 suicide attempt. These results are consistent with our cross-sectional data (Wong et al., 2005). Girls reported more stressful events and higher levels of depressive symptoms than boys. They were more likely to report suicidal ideation in the year before, had been exposed to suicide attempts by others, and to have made an attempt before baseline. Girls who went on to attempt suicide showed more depressive symptoms at baseline, in comparison both to non-attempting girls and to boys who attempted suicide between T1 and T2. Suicide attempt prior to T1 and other risk factors: overlapping or independent variance? All T1 risk factors except pre-T1 suicide attempt were entered in the initial step of a multivariate regression analysis to determine their ability to predict subsequent suicidal behavior. The effect of a pre-T1 suicide attempt was assessed in the final step in the modelling. T1 levels of depression, substance use, and suicidal ideation were found to contribute significant independent risk for subsequent suicidal behavior in the whole group of participants. The effect of depression on the subsequent suicidal behavior was moderated by gender: depression was a significant independent risk factor for suicidal acts among girls, but not among boys. When pre-T1 suicidal behavior was added in the second set of the analysis (second column of numbers in Table 2), only T1 suicidal ideation and the presence of a preT1 suicide attempt were significant predictors of post-T1 suicidal behavior. Information about previous suicidal behavior was therefore independent
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
237
Table 1 Risk factors at T1 for a suicide attempt between T1 and T2 Risk factors at T1
Demographics Age Number of girls (%) Parental educationa Living in a single-parent family (%) Psychopathology Depressive symptomsb Depression score in top 10% n (%) Anxiety symptomsb Substance use (%)
Controls (no attempt between T1 and T2) Mean (SD)
Attempters (attempt between T1 p for effect o0.05 and T2) Mean (SD)
Boys (n ¼ 708)
Girls (n ¼ 342)
Boys (n ¼ 24)
Girls (n ¼ 25)
Total (n ¼ 49)
14.22 (1.22) – 3.79 (0.56)
15.22 14.55 (1.43) (1.57) – 342 (32.6) 3.67 (0.62) 3.75 (0.58)
15.09 (1.55) – 3.70 (0.71)
14.67 (1.31) 25 (51.0) O 3.69 (0.57)
66 (9.3)
45 (13.2)
111 (10.6)
14.25 (0.87) – 3.67 (0.42) 2 (8.3)
3 (12.0)
5 (10.2)
19.83 (7.19) 43 (6.1)
22.67 (8.42) 54 (15.8)
20.76 (7.72) 21.67 (6.41) 97 (9.2) 0
31.73 (8.30) 10 (40.0)
26.70 (8.92) 10 (20.4)
18.97 (4.63) 13 (1.8)
19.82 (5.56) 8 (2.3)
19.24 (4.97) 22.21 (6.19) 21 (2.0) 3 (12.5)
21.33 (4.80) 3 (12.0)
21.77 (5.49) 6 (12.2)
Total (n ¼ 1050)
Environmental stress/protective variables 1.64 (1.70) 2.09 (1.80) 1.79 (1.74) Life stressb Family relationshipsa
7.92 (1.62) 7.70 (1.68) 7.85 (1.64)
Suicide-related variables Suicidal ideation (%) 79 (11.2) Exposure to suicide attempt (%) 36 (5.1) Suicide attempt in 12 months 9 (1.3) prior to T1 (%)
56 (16.4) 39 (11.4) 7 (2.0)
135 (12.9) 75 (7.1) 16 (1.5)
Attempt status
Sex Attempt by sex O
O
O
O
O
O
O O
2.32 (1.91) 7.95 (1.69)
3.73 (2.16) 3.02 (2.14) O
9 (37.5) 1 (4.2) 2 (8.3)
10 (40.0) 4 (16.0) 6 (24.0)
O
7.68 (1.71) 7.81 (1.68)
19 (38.8) 5 (10.2) 8 (16.3)
O O
O O O
Note: The continuous variables were analyzed by an initial MANOVA which was significant (po0.001) for attempt status, sex, and attempt status by sex. Categorical variables were compared using chi-square analyses. a Higher scores indicate better parental education and family relationships. b Higher scores indicate higher levels of symptoms and stress.
of other risk factors in predicting a future suicide attempt. Change in risk factors from initial measure at T1 to postsuicide attempt at T2 The presence of an attempt between the two surveys was examined as a correlate of change in risk variables. Table 3 shows that suicide attempts occurring between T1 and T2 were significantly associated with increased substance use, suicidal ideation, depressive symptoms, anxiety, life stress, and poorer family relationships at T2 compared to T1. Sex by attempt status interactions were not significant, suggesting that there were similar
changes over time for the boys and the girls who made an attempt. Thus, at reevaluation after a suicide attempt, some of the factors that place the adolescent at risk for future suicidal behavior were exacerbated even further, showing increased strength compared to their baseline levels. Discussion Findings for this prospective study extend our cross-sectional results, suggesting that, in the absence of recent suicidal behavior among adolescents, depression, substance use, and suicidal ideation are important and independent predictors of subsequent suicidal behavior. When suicidal
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
238
Table 2 Unique contribution of risk factors at T1 for predicting suicide attempt between T1 and T2 Adjusted OR (95% CI)a for T1 predictors for all the participants, n ¼ 1099 Sex Depressive symptoms (per score) Anxiety symptoms (per score) Substance use (yes/ no) Life stress (per score) Suicidal ideation (yes/ no) Suicide attempt in 12 months prior to T1 (yes/no)
Adjusted OR (95% CI)a including history of suicide attempt in 12 months before T1, n ¼ 1099
1.49 (0.80–2.77) 1.46 (0.78–2.75) 1.05 (1.00–1.11)*,b 1.05 (0.99–1.10) 1.01 (0.94–1.08)
1.00 (0.93–1.08)
3.37 (1.15–9.83)*
2.96 (0.98–8.96)
1.07 (0.91–1.26) 2.80 (1.47–5.35)**
1.05 (0.89–1.25) 2.41 (1.22–4.77)*
–
3.85 (1.33–11.17)*
*po0.05, **po0.01. a The OR for risk factors are all adjusted for each other in the logistic regression model. b Sex moderated these results (OR for interaction of sex by depression ¼ 1.08, CI ¼ 1.00–1.16, po0.05) such that depression was a predictor for girls but not for boys at this step.
Table 3 The effect of a suicide attempt between T1 and T2 on the potential risk factors at T2 (controlling for the risk factor and the presence of suicide attempt at T1) Risk factors (dependent measure) at T2
Substance usea (yes ¼ 6; no ¼ 43) Suicidal ideationa (Yes ¼ 19; No ¼ 30) Family relationshipsc Depressive symptomsd Anxiety symptomsd Life stressd
Prediction offered by the presence of suicide attempt to change in risk factor from T1 Adjusted OR (95% CI); p 4.80 (2.00–11.54); po0.01 3.85 (2.09-7.10); po0.001 Bb; t; p 0.08;2.73; po0.01 0.09; 3.25; po0.005 0.10; 3.45; po0.005 0.10; 3.26; po0.005
a
Coded as present or absent. Standardized regression coefficient. c Higher scores indicate better family relationships. d Higher scores indicate higher levels of symptoms and stress. b
behavior in the previous year is present, however, suicidal ideation identifies those adolescents likely to repeat their self-destructive behavior better than
the other risk factors. Distress measures (substance use, suicidal ideation, poor family relationships, depression, anxiety, and life stress—some of which are also risk factors for suicidality) appear to be exacerbated compared to baseline when assessed following self-destructive acts, and may serve as a mechanism by which future suicide attempt is potentiated by past attempt. Typically, suicide attempt has been studied as an outcome—the hypothesized result of psychological, environmental, and other risk factors that trigger these behaviors (e.g., King et al., 2001; Yip et al., 2004). Yet it is also possible that suicidal acts themselves may impact the environment in which an adolescent functions. Substance use became non-significant as a risk factor for suicidal behaviors when previous suicide attempt was added in the model, likely because of its rarity in this Asian culture. There were only 27 youth who acknowledged using substance(s) (i.e., drugs, cigarettes, or alcohol) during the past 12 months; six of them attempted suicide in the time period of the study. Relatively high-frequency behaviors in the West may denote more pathology in Hong Kong where they are much less common, as suggested by our past findings in relation to other risk behaviors (Lam, Stewart, Ho, & Youth Sexuality Study Task Force, 2001). It is noteworthy that the number of suicide attempts from T1 to T2 nearly doubled. During the time period in between the two surveys, the singer, actor, and popular celebrity, Leslie Cheung, committed suicide. In the months that followed there was a sharp increase in the suicide deaths in Hong Kong that have been attributed to the sensational media coverage that followed (Yip et al., 2005). It is possible that the attempts also increased during the period that followed Leslie Cheung’s suicide. At T2, we identified 38 participants who reported a single suicide attempt and 27 who had made two or more attempts since the year prior to the baseline through the follow-up period. In post hoc analyses we considered whether they were different on the variables examined in this study. At T2, multiple attempters were significantly more depressed than single attempters (M, SD ¼ 33.16, 8.64 versus 23.22, 9.00, po0.001). They were also more anxious (25.48, 7.55 versus 21.34, 5.55, po0.05), reported more stressful events (3.93, 2.67 versus 1.76, 1.72, po0.001) and worse family relationships (6.57, 1.75 versus 7.64, 1.47, po0.01). They were more likely to
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
report substance abuse (OR ¼ 5.83, CI ¼ 1.40–24.25, po0.05) and suicidal ideation (OR ¼ 8.91, CI ¼ 2.86–27.74, po0.001) in the previous year. These findings provide some additional support to our hypothesis that suggests that each suicide attempt is associated with increased risk for further suicidal acts. Culture may moderate the findings that a suicide attempt is associated with increased stress in social and family interactions. In the West, Chiles et al. (1989) have described changes in the environment after an attempt as family members and close friends responded to the act with feelings of guilt and empathic support. Aldridge (1998) has likewise suggested that the ‘‘sick role’’ played by the suicidal individual may actually unite the family after a suicide attempt. Given the importance in Chinese culture of bringing honor to the family and avoiding disgrace (Ho, 1996), suicidal behaviors are likely to cause significant familial distress. It is notable that, in our study, family relationships deteriorated for suicide attempters from T1 to T2. Whether suicide attempts elicit different responses from social groups in the West than they do in Hong Kong remains a question for further cross-cultural study. The present study has both clinical and research implications. A suicide attempt may be accompanied by dynamic processes that lower the threshold for the next attempt. Previous attempt plus recent suicidal ideation are the two most salient risk factors. In the absence of information about a previous attempt, depressive symptoms, substance use, and suicidal ideation are important indicators of risk. Joiner et al. (2005) have proposed that, once an attempt is made, future attempts are disinhibited. Our study focuses instead on some of the critical change variables associated with a destructive spiral associated with the suicidal behavior, which include increased substance use, increased suicidal ideation, poorer family relationships, increased levels of depression and anxiety, and increased life stress. If the interventionists can target these factors, they may reduce the risk of repeated suicidality. The survey method over a relatively long period of time of 1 year does not allow us to determine the timing of the increased distress observed at T2. It is possible that increased distress preceded and precipitated the attempt rather than followed it. Although information about the complex temporal relationships is necessary to elaborate the model, at this point it is notable that distress was up a notch following a pre-T1 suicide attempt. It is quite
239
reasonable to assume that there could be multiple contributors to the distress, many of which could have preceded the post-T1 attempt. However, it is the presence (or persistence) of this distress following a pre-T1 suicide attempt that is at the crux of the model because of its possible influence over the future attempts. Future studies are necessary to elaborate the timing, the source, and the persistence of increased distress noted at T2. Repeated contacts over shorter periods of time, collecting both quantitative and qualitative information, are needed. It is also important to acknowledge that the trait and the crescendo models have been separated for simplicity. There are likely to be components of trait risk that apply even if a previous attempt enhances the risk for a future attempt. For example, a family history of suicidality and gender (acting through biological and psychosocial variables) are considered ‘‘immutable’’ risk factors. However, once an attempt has been made, other factors may also come into play, some as a result of the attempt. We are not aware of any completed suicides in our cohort in between the surveys. Prior to the T2 survey, school representatives were asked if any of their students had completed suicide after T1. No suicide deaths were reported. It is possible, but not likely, that older students who left or dropped out of school may have completed suicide without the knowledge of the school administration. However, Hong Kong remains a communal culture, and the death of a child who has been a student in the school is likely to be well known. The talk after the T1 survey might have had a salutary effect on some of the listeners and we do not know if it affected the results. However, there has been a general effort through the Department of Health in Hong Kong to increase awareness of depression and suicidality in the schools. This talk, therefore, would be only one component of an environment designed to enhance help-seeking among suicidal youth. Other limitations of our study include the exclusive use of self-report methods. There may be under-reporting of suicide attempts despite the anonymous nature of the survey. Our study was not powered to detect small effect sizes, even though the sample size is respectable for a study of suicide attempters. When attempters were broken down by sex, very small groups resulted with little power to detect differences. Other analyses, such as those examining the influence of drug use, also involved
ARTICLE IN PRESS 240
J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241
small sample sizes and should be cautiously considered. We did not assess some important additional risk factors such as impulsivity and sexual abuse. Furthermore, some of the univariate predictors may be mediated by those that retain direct effects in the multivariate model. For example, stressors may exert their influence on suicidality by increasing depressive symptoms, or substance use may disinhibit and predispose towards suicidal ideation. Larger sample sizes and multiple data collection points are needed to investigate such mediational models. Conclusions Depressive symptoms, substance use, and suicidal ideation predicted a suicide attempt within the next 12 months in adolescents in Hong Kong. For youth who reported that they had not made a pre-T1 suicide attempt, substance use and suicidal ideation were strong predictors. When a recent suicide attempt was included in the model, only suicidal ideation and pre-T1 attempt were significant independent predictive factors for future attempt. Our findings support the model that proposes that a previous suicide attempt is an independent and powerful predictor of future attempts. Although the timing of this exacerbation cannot be determined, suicide attempt between T1 and T2 was associated with worse family relationships and increase in substance use, suicidal ideation, depression, anxiety, and life stress at T2. Repeat attempters may therefore be vulnerable to exacerbated risk factors that persist or are enhanced following a suicide attempt. Acknowledgments We thank Charles D. Spielberger and Paul Yung for granting permission to use the original and Chinese version of the State–Trait Anxiety Inventory. We thank Daniel Ho for his involvement in the fieldwork and data management, and Ben Cowling and Irene Wong for their statistical advice. We also thank the Healthy District Steering Committee, Central and Western District Board for financial support and, the Chairman, Mr. W.H. Lai for arranging social workers to follow up the students who were screened as at risk, participating schools in the district, parents, and students for their cooperation.
References Aldridge, D. (1998). The politics of symptoms and marital conflict. In Suicide: The tragedy of hopelessness. London and Philadelphia: Jessica Kingsley Publishers. Centers for Disease Control and Prevention (CDC). (1998). Youth risk behavior surveillance—United States, 1997. Morbidity and Mortality Weekly Report, 47(SS-3), 1–89. Chiles, J., Strosahl, K., Ping, Z. Y., Michael, M., Jamelka, R., Senn, B., et al. (1989). Depression, hopelessness and suicidal behavior in Chinese and American psychiatric patients. American Journal of Psychiatry, 146, 339–344. Clark, D. C., Gibbons, R. D., Fawcett, J., & Scheftner, W. A. (1989). What is the mechanism by which suicide attempts predispose to later suicide attempts? A mathematical model. Journal of Abnormal Psychology, 98(1), 42–49. CSRP. (2005). Statistics. Hong Kong Jockey Club Centre for Suicide Research and Prevention, University of Hong Kong, Hong Kong. URL: /http://csrp.hku.hk/WEB/eng/statistics. aspS [WWW page]. Grunbaum, J. A., Kann, L. K., Kinchen, S. A., Williams, B., Ross, J. G., Lowry, R., et al. (2002). Youth risk behavior surveillance—United States, 2001. CDC MMWR surveillance summaries (Vol. 51(SS04), pp. 1–64), June 28, 2002. URL: /http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5104a1.htmS [WWW page]. Hawton, K., & Fagg, J. (1988). Suicide and other causes of death, following attempted suicide. The British Journal of Psychiatry, 152, 359–366. Hawton, K., Harriss, L., & Zahl, D. (2006). Deaths from all causes in a long-term follow-up study of 11,583 deliberate self-harm patients. Psychological Medicine, 36(3), 397–405. Ho, D. Y. F. (1996). Filial piety and its psychological consequences. In M. H. Bond (Ed.), The handbook of Chinese psychology (pp. 155–165). New York: Oxford University Press. Joiner, T. E., Conwell, Y., Fitzpatrick, K. K., Witte, T. K., Schmidt, N. B., Berlim, M. T., et al. (2005). Four studies on how past and current suicidality relate even when ‘‘everything but the kitchen sink’’ is covaried. Journal of Abnormal Psychology, 114(2), 291–303. King, R. A., Schwab-Stone, M., Flisher, A. J., Greenwald, S., Kramer, R. A., Goodman, S. H., et al. (2001). Psychosocial and risk behavior correlates of youth suicide attempts and suicidal ideation. Journal of American Academy of Child and Adolescent Psychiatry, 40, 837–845. Krug, E. G., Mercy, J. A., Dahlberg, L. L., & Zwi, A. B. (2002). The first world report on violence and health. The Lancet, 5(360), 1083–1088. Lam, T. H., Stewart, S. M., Ho, L. M. & Youth Sexuality Study Task Force. (2001). Prevalence and correlates of smoking and sexual activity among Hong Kong adolescents. Journal of Adolescent Health, 29, 352–358. Lam, T. H., Stewart, S. M., Yip, P. S. F., Leung, G. M., Ho, L. M., Ho, D. S. Y., et al. (2004). Suicidality and cultural values among Hong Kong adolescents. Social Science & Medicine, 58, 487–498. Lewinsohn, P., Rohde, P., & Seeley, J. (1994). Psychosocial risk factors for future adolescent suicide attempts. Journal of Consulting and Clinical Psychology, 62, 297–305.
ARTICLE IN PRESS J.P.S. Wong et al. / Social Science & Medicine 66 (2008) 232–241 Radloff, L. S. (1977). The CES-D scale: A self-report depression scale for research in the general population. Applied Psychological Measurement, 1, 385–401. Spielberger, C. D., Gorsuch, R. L., & Lushene, R. E. (1970). Manual for the state– trait anxiety inventory. Palo Alto, CA: Consulting Psychologists Press. Stewart, S. M., Lewinsohn, P., Lee, P. W. H., Ho, L. M., & Kennard, B. D. (2002). Symptoms patterns in depression and ‘‘subthreshold’’ depression among adolescents in Hong Kong and the United States. Journal of Cross-Cultural Psychology, 33, 559–576. Tzeng, W. C., & Lipson, J. G. (2004). The cultural context of suicide stigma in Taiwan. Qualitative Health Research, 14(3), 345–358. WHO Statistical Information System. (2005). WHO mortality database. URL: /http://www3.who.int/whosis/menu.cfm? path=whosis,mortS [WWW page]. Wong, J. P. S., Ho, S. Y., & Lam, T. H. (2004). Central and western district adolescent health survey 2002– 2003 full baseline report. Department of Community Medicine, The University of Hong Kong.
241
Wong, J. P. S., Stewart, S. M., Ho, S. Y., Rao, U., & Lam, T. H. (2005). Exposure to suicide and suicidal behaviors among Hong Kong adolescents. Social Science & Medicine, 61, 591–599. Yip, P. S. F., Fu, K. W., Yang, K. C. T., Ip, B. Y. T., Chan, C. L. W., Chen, E. Y. H., et al. (2005). The effects of a celebrity suicide on suicide rates in Hong Kong. Journal of Affective Disorders, 93, 245–252. Yip, P. S. F., Liu, K. Y., Lam, T. H., Stewart, S. M., Chen, E., & Fan, S. (2004). Suicidality among high school students in Hong Kong, SAR. Suicide and Life-Threatening Behavior, 34(3), 284–297. Yung, P. M. B., Chui-Kam, S., French, P., & Chan, T. M. (2002). A controlled trail of music and pre-operative anxiety in Chinese men undergoing transurethral resection of the prostate. Journal of Advanced Nursing, 39, 532–539. Zahl, D. L., & Hawton, K. (2004). Repetition of deliberate selfharm and subsequent suicide risk: Long-term follow-up study of 11,583 patients. The British Journal of Psychiatry, 185, 70–75.