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Prediction of Insomnia Severity Based on Cognitive, Metacognitive, and Emotional Variables in College Students
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Prediction of Insomnia Severity based on Cognitive, Metacognitive and Emotional Variables in College Students Hoda Doos Ali Vand M.A., Banafsheh Gharraee PhD., Ali-Asghar Asgharnejad Farid PhD., MirFarhad Ghaleh Bandi MD.
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Cite this article as: Hoda Doos Ali Vand M.A., Banafsheh Gharraee PhD., Ali-Asghar Asgharnejad Farid PhD., MirFarhad Ghaleh Bandi MD., Prediction of Insomnia Severity based on Cognitive, Metacognitive and Emotional Variables in College Students, Explore, http://dx.doi.org/10.1016/j.explore.2014.04.005 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Prediction of Insomnia Severity based on Cognitive, Metacognitive and Emotional Variables in College Students
Hoda Doos Ali Vand1, Banafsheh Gharraee2*, Ali-Asghar Asgharnejad Farid 3, MirFarhad Ghaleh Bandi 4
1
M.A. in Clinical Psychology, Tehran Institute of Psychiatry – Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences , Department of Clinical Psychology, Tehran, I. R. Iran.
2
PhD. in Clinical Psychology, Assistant Prof of Mental Health Research Center, Tehran Institute of Psychiatry –Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences , Department of Clinical Psychology, Tehran, I. R. Iran.
3
PhD. in Clinical Psychology, Assistant Prof of Mental Health Research Center, Tehran Institute of Psychiatry –Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences , Department of Clinical Psychology, Tehran, I. R. Iran.
4
MD. in Psychiatry, Associate Prof of Mental Health Research Center, Tehran Institute of Psychiatry – Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences , Department of Psychiatry, Tehran, I. R. Iran.
*Corresponding Author: Assistant Prof Mental Health Research Center, Tehran Institute of Psychiatry – Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences, Department of Clinical Psychology, Tehran, I. R. Iran., P.O. Box 1445613111, Email: [email protected] * Correspondence should be sent to: Banafsheh gharaee, Ph.D, University of Medical Sciences & Health Services, Psychiatry Institute, Department of Clinical Psychology, Tehran, Iran P. O. Box 1445613111
Tel: 00989123386397 Fax: 00982166551575 Email: [email protected]
Prediction of Insomnia Severity based on Cognitive, Metacognitive and Emotional Variables in College Students
Abstract Objective: Insomnia is the most common sleep disorder whose origin is attributed to various variables. The current study aims to predict the symptoms of insomnia by investigating some of its predictors.
Methods: Numerous variables such as depression and anxiety symptoms, worry, pre-sleep arousal (cognitive arousal and somatic arousal), dysfunctional cognitions and metacognitive beliefs about sleep were assessed as insomnia predictors. 400 students of Tehran University of Medical Sciences completed Depression- Anxiety- Stress Scale (DASS), Penn State Worry Questionnaire (PSWQ), Pre-Sleep Arousal Scale (PSAS), Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-10), Metacognitions Questionnaire-insomnia (MCQ-I), and Insomnia Severity Index (ISI).
Results: All variables were significantly correlated with insomnia symptoms (P<0.001). Stepwise multiple regression analysis suggested a predictive model for insomnia including cognitive arousal, dysfunctional beliefs about sleep, metacognitive beliefs about sleep, and depressive symptoms.
Conclusions: The findings underline the significant role of cognitive and metacognitive variables for predicting insomnia symptoms. Moreover, the results suggest that metacognitive beliefs about sleep may need to be considered as a significant component in the context of insomnia.
Keywords: Insomnia, Depression, Anxiety, Worry, Arousal, Cognition, Metacognition.
INTRODUCTION Insomnia is defined as difficulty in falling asleep, difficulty in remaining asleep, early morning awakening and/or non-restorative sleep, associated with daytime consequences [1]. In the last decade, national and international studies have consistently shown that insomnia is a common problem in the general population of many countries [2-4]. It is estimated that about one-third of the general population present at least one of the insomnia symptoms and when daytime consequences of insomnia are included, the prevalence will be between 9% and 15% [5]. Insomnia is associated with varieties of psychiatric conditions especially depression and anxiety [6-8] and it seems that there is a bi-directional relationship between these variables and insomnia [9] .
Over the years, several models have been presented in the context of insomnia helping researchers to understand the variables that cause and perpetuate this condition [10-13]. These models identify persistent insomnia as a problem with several dimensions and it is proposed that many mechanisms contribute to its maintenance reciprocally. Although there are differences between these models, all of them consider physiological, cognitive, affective, and behavioral factors as prominent variables in developing insomnia [14].
It has been documented that cognitive processes play a significant role in insomnia and other disorders with concomitant sleep disruption [15, 16]. It is stated that dysfunctional beliefs and attitudes toward sleep are the most researched cognitive phenomenon in the context of insomnia. Five important classes of unhelpful beliefs about sleep have been proposed: misconceptions about the causes of insomnia, misattributions or amplifications of the consequences of insomnia, unrealistic sleep expectations, diminished perception of control over sleep, and faulty beliefs about sleep promoting practices [10]. Another cognitive phenomenon is pre-sleep worry that is viewed as an important variable preventing the individual from falling asleep. It has been shown that people with insomnia frequently experience unpleasant intrusive thoughts and excessive and uncontrollable worry as a disturbing factor during the pre-sleep period [17].
There has been a surge of interest in the role of arousal as an integrative approach in understanding insomnia (especially primary insomnia (PI) or psychophysiological insomnia). This perspective assumes that psychological and physiological components play a reciprocal role in development and maintenance of chronic insomnia. It is proposed that arousal is expressed in terms of somatic, cognitive and cortical activation [18].
In recent years, some studies have provided evidence supporting the idea that metacognitive beliefs and strategies play an important role in primary insomnia. “Metacognition can be defined as internal cognitive factors that control, monitor and appraise thinking. It can be subdivided into metacognitive knowledge (e.g., I must worry in order to cope), experience (e.g., a feeling of knowing) and strategies (e.g., ways of controlling thoughts and protecting beliefs)” [19]. It is shown that insomniac patients selectively attend to salient internal and external threat cues [20]. Harvey (2003) found that primary insomniac patients endorse more positive belief statements about worry [21]. Moreover, it is demonstrated that using thought control strategies, for instance worry, reappraisal, thought suppression and punishment, is very common in people with primary insomnia [22]. In addition, hardly do they try to sleep and tend to control sleep onset anxiously [23] .
Medical students is a specific group that suffers more from insomnia; they have thus received special attention in insomnia researches [24]. To have an appropriate description of the profile of individuals with insomnia, it is helpful to examine several variables simultaneously in a specific population. Investigating correlates of insomnia in individuals with less severe insomnia rather than treatment-seeking individuals can help with developing effective early intervention programs to prevent the development of chronic insomnia and the pursuant mental health disorders [25].
According to these issues, the first objective of the present study is to determine relations of some important variables with insomnia symptoms in Iranian students. Specially, examining the relationship between metacognitions and insomnia symptoms in a nonclinical population was in authors’ interest. The second objective is to determine the priority of these variables in prediction of insomnia severity. According to the search conducted by the authors, no study in insomnia literature has examined all of these variables together. The current study is new with regard to including metacognitions along with other variables to determine its priority among other components. In this study, depressive and anxiety symptoms, worry, pre-sleep arousal (cognitive and somatic arousal), dysfunctional beliefs about sleep and metacognitive beliefs about sleep are assessed as predictors of insomnia severity.
METHODS Participants Multistage cluster sampling was used to select a representative population from Tehran University of Medical Sciences. At first, 4 schools including medicine; nursing and midwifery; rehabilitation; management and medical information were selected randomly. Then, in every school, according to the proportion of students in any academic level, some classes were selected randomly and questionnaires were distributed among the students. According to community size, 430 medical students of Tehran University were invited to participate.
Procedures The current study was carried out as a correlational retrospective study in which insomnia symptoms were the criterion variable and depressive and anxiety symptoms, pre-sleep arousal, dysfunctional beliefs and attitudes about sleep and metacognition beliefs related to insomnia were the prediction variables. The first pages of the questionnaires informed participants of the purpose and nature of the study. In addition, this section assured them of their anonymity and asked participants to provide informed consent by marking a statement before completing other questionnaires. In addition to the six published scales and basic demographic information, questions relating to mental or physical disorder, hypnotic use, and work shift were also included. Participants were asked whether they had a medical or psychiatric disorder which, according to their physician or psychiatrist, could cause insomnia. If the response was yes, they would be asked to explain more about that problem. In addition, participants who took hypnotic drugs or had work shifts at night were excluded. The study was approved by the ethical and research committee of Tehran University of Medical Sciences.
Measures Depression, Anxiety and Stress Scale (DASS-21): DASS-21 is a 4-point Likert scale (0=did not apply to me at all; 3=applied to me very much, or most of the time) with three factors that measure: (1) three negative emotional states of depression (seven items); (2) anxiety (seven items); and (3) stress (seven items). It is a short version of the DASS 42-item scale [26, 27]. DASS-
21 is of great validity and reliability among Iranian specialists. Validity coefficients are reported as 0.81 for depression, 0.78 for anxiety, 0.80 for mental pressure and 0.82 for total scale. Internal consistency coefficients are also reported as 0.85 for depression factor, 0.75 for anxiety, and 0.87 for mental pressure. Test-retest reliability of the total scale for 3 weeks is reported as 0.82 [28]. In this study, depression and anxiety subscales of DASS-21 were used for measuring depressive and anxiety symptoms. Penn State Worry Questionnaire (PSWQ): This self-report questionnaire consists of 16 items. It is designed to measure the excessiveness, duration and uncontrollability of worry as experienced in GAD patients. The PSWQ is of high reliability, adequate temporal stability and substantial validity in the assessment of trait worry [29-30].PSWQ has exhibited good psychometric properties in Iran. Cronbach alpha equals 0.88 for the total questionnaire, and test-retest reliability of the total scale for 1 month is reported as 0.79 [31]. Pre-Sleep Arousal Scale (PSAS): PSAS is a self-report scale containing 16 items. This fivepoint Likert scale (1, “not at all” to 5, “extremely”) has two subscales (somatic and cognitive arousal) [32]. Internal consistency of the PSAS has been adequate (α=.76 and .81 for the somatic and cognitive scales, respectively), and high PSAS scores have been associated with sleep onset difficulties [33].This scale was translated into Persian for the purpose of the study. Results supported the internal consistency (α=.72 and .84 for the somatic and cognitive scales, respectively) and its concurrent validity with Pittsburgh Sleep Quality Index (PSQI) (r=.71, P< .01). Test-retest reliability of the total scale for 2 weeks in 30 participants was .88 (P<.01).
Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-10): This scale assesses sleeprelated beliefs and is the short version of DBAS-30 [34, 10]. Each statement contains a 10centimeter horizontal line with poles labeled ‘‘strongly agree’’ and ‘‘strongly disagree’’. The total score is based on the average score of all items and ranges from 0 to 10. Studies have demonstrated DBAS-10 to be a satisfactory instrument [34].This scale was translated into Persian for the purpose of the study. Results supported the internal consistency (α=.91) and its concurrent validity with PSQI (r=.45, P< .05). Test-retest reliability of total scale for 2 weeks in 30 participants was .83 (P<.01).
Metacognitions Questionnaire–Insomnia (MCQ-I): The Metacognitions Questionnaire – Insomnia (MCQ-I) is a 60-item and a self-report measure that assesses metacognitive beliefs in insomnia. It is demonstrated that primary insomniac patients score significantly higher than normal sleepers on MCQ-I. The MCQ-I has been correlated significantly with MCQ-30. This questionnaire is of adequate validity and reliability [35].This scale was translated into Persian for the purpose of the study. Results supported the internal consistency (α=.95) and its concurrent
validity with MCQ-30 (r=.38, P< .05). Test-retest reliability of total scale for 2 weeks in 30 participants was .87 (P<.01).
Insomnia Severity Index (ISI): ISI was employed for the assessment of insomnia severity in the population under study [36]. This questionnaire has seven items that measure: (1) severity of sleep onset; (2) sleep maintenance and early morning waking; (3) satisfaction with current sleeping patterns; (4) interference with daily functioning; and (5) noticeability of sleep impairment and the associated degree of worry and anxiety. Participants were asked to rate their perception of each ISI item on a 5-point scale (0=not at all; 4=very much). Scores range between 0 and 28. Higher scores indicate a high perception of insomnia. This scale was translated into Persian for the purpose of the study. Results showed that this scale has satisfactory internal consistency (α=.81) and test-retest reliability for 2 weeks in 30 participants was .72 (r=.72, P<.01). Its concurrent validity with PSQI was .80 (P< .01). Analysis The data were first summarized to provide descriptive statistics. The correlation between variables was analyzed with Pearson correlations. T-tests were used to test for gender and marital status differences on insomnia severity. To examine differences on insomnia severity between the three residency status groups (dormitory, with parents, personal home) and between the four academic level groups, analysis of variance was used. Stepwise multiple regression analysis was conducted with the aim of identifying independent predictors of insomnia severity, and the relative importance of specific predictors of insomnia. Variables that have been shown in previous studies to correlate with insomnia (depression, anxiety, worry, pre-sleep arousal, dysfunctional beliefs about sleep, and metacognitive beliefs about sleep) were used as independent variables in the regression. All data were analyzed using the SPSS 18.0 software package. Table 1 show the descriptive statistics of the demographic variables and table 2 shows means and standard deviations of all variables in this study.
RESULTS 6.9% of students did not return their questionnaires and were excluded from the study. Only 1% of the population had medical or psychiatric disorder and were excluded from the study. Finally, a total of 400 students (166 male, 234 female) composed our study population. Participants were students between the ages of 20 and 46. Of these participants, 44.8% were undergraduate students (N=179), 18% were master students (N=72), 6.5% were Ph.D students (N=26), and 30.8% were medical students (N=123). The mean age was 22.18 (SD=4.06 years). Moreover, 60.3% (N=241) were living in dormitory, 32.3% (N=129) were living with their parents and 7.5% (N=30) had their own private houses. 91.5% (N=366) were single and 8.5% (N=34) were married. The participants who did not return their questionnaires did not differ significantly from those who returned their questionnaires.
ANOVA was used to determine whether there were any statistical differences between different gender groups as well as groups of different marital statuses in insomnia severity. The results of ANOVA showed that different gender groups (F = 10.56, P < 0.001) as well as groups belonging to different marital statuses (F= 6.765, P<0.05) experienced significantly different severities of insomnia which was higher in females and in singles than males and the married.
To determine whether individuals with different residency status and academic levels exhibited statistical differences of insomnia severity, analysis of variance with Tukey post hoc test was employed. Analysis of variance showed that there were significant differences of insomnia severity for individuals with different residency statuses (F = 4.31, P<0.01), but no significant differences of insomnia severity between individuals of different academic levels (F = 1.79, P = 0.14). Post hoc tests revealed that pairwise differences among the means were significant for
individuals living in dormitory and the ones living with parents (P< 0.05) as well as the ones living in dormitory and having their own private house (P<0.05) and individuals living in dormitory had higher mean scores on the ISI. Table 3 presents the Pearson correlations between predictor variables and severity of insomnia. Inspection of the correlation matrix revealed that DASS-21, PSWQ, PSAS, DBAS-10 and MCQI were correlated significantly with ISI scores. The strongest correlation was between cognitive arousal and ISI scores. To examine whether depressive and anxiety symptoms, worry, pre-sleep arousal (cognitive and somatic arousal), dysfunctional beliefs about sleep and metacognitive beliefs about sleep were related to insomnia symptoms, stepwise regression analyses were utilized. The following variables were entered as predictor variables: dysfunctional beliefs about sleep (DBAS-10), metacognitive beliefs about sleep (MCQ-I), worry (PSWQ), cognitive arousal (PSAS1), somatic arousal (PSAS2), anxiety (DASS-A), depression (DASS-D). Table 4 shows the results of the hierarchical regression analyses.
As shown in Table 4, R (for regression) was significantly different from zero [F=73.91, P<0.001]. Cognitive arousal, dysfunctional beliefs about sleep, metacognitive beliefs about sleep and depressive symptoms contributed significantly to the prediction of insomnia severity as indicated by the β weights displayed in Table 4.
DISCUSSION The first objective of the present study was to determine the correlation of depressive and anxiety symptoms, worry, pre-sleep arousal (cognitive and somatic arousal), dysfunctional beliefs about sleep, and metacognitive beliefs about sleep with insomnia severity. The results showed that all predictive variables were significantly correlated with insomnia symptoms. The second objective of the present study was to determine the priority of these variables in predicting insomnia severity. There was evidence that cognitive arousal, dysfunctional beliefs about sleep, metacognitive beliefs about sleep and depressive symptoms contributed significantly to the prediction of insomnia severity. Cognitive arousal accounted for the greatest degree of variance in the prediction of insomnia symptoms followed by dysfunctional beliefs about sleep, metacognitive beliefs about sleep and depressive symptoms. In total, these variables accounted for 42% of variance of insomnia symptoms. However, anxiety, worry and somatic arousal were excluded from the model.
This study, similar to the previous studies [37-38], revealed a positive correlation between depressive symptoms and insomnia (r=0.37). But the weight of depressive symptoms in predicting insomnia was low. There is evidence suggesting bidirectional relationship between depression and insomnia [9]. A review study [39] showed that insomnia had predictive value for future depression. Thus, although there is a relationship between these two variables, the association does not seem to be a simple causal relationship. In one study that depression was the first variable in predicting insomnia, it was considered along with medical conditions [40]. In the current study, depression was considered along with cognitive and metacognitive variables and this may reduce the proportion of depression in predicting insomnia. Moreover, the means of depression and insomnia severity according to guidelines of ISI and DASS-21 are not at a severe level (22-28= severe clinical insomnia; 21-27=severe depression) in the population of the current study and this may account for the low correlation between insomnia severity and depressive
symptoms. Our study showed that insomnia severity is related with depressive symptoms in nonclinical students with a different culture.
The relationship between dysfunctional beliefs about sleep and insomnia symptoms is supported in the current study. This finding is consistent with other studies that showed sleep-disruptive beliefs playing an important role in sleep difficulties [41-43]. People with insomnia indicate dysfunctional beliefs and attitudes about sleep frequently. These unhelpful cognitions are less flexible and, thus, are more maladaptive than the sleep-related beliefs of normal sleepers [44]. Cognitive models of insomnia suggest a central role for such disruptive beliefs about sleep in insomnia [12]. However, there may be a bidirectional relationship between these two variables and dysfunctional beliefs may be a result of chronic poor sleep.
Results of the current study showed that pre-sleep arousal can predict severity of insomnia. Despite the fact that both cognitive and somatic arousal had a positive significant correlation with insomnia symptoms, cognitive arousal was a more important variable than somatic arousal in predicting insomnia symptoms and somatic arousal was excluded from the model. In total, it is shown that cognitive arousal has a stronger correlation than somatic arousal with insomnia. Lichstein and Rosenthal [45] found that insomniacs attributed their difficulties in sleeping to cognitive arousal (i.e., the mind being very active at bedtime, thinking, worrying, planning, analyzing, difficulty in controlling thoughts) rather than somatic arousal (i.e., being aware of one's body as restless, shifting, sweaty, etc.). It is revealed that although both cognitive and somatic arousal are significantly associated with sleep disturbances, the strongest association was between cognitive arousal and sleep difficulties [46].On the other hand, it seems that cognition and physiology are not two completely opposing systems, but they should be considered as simultaneous systems. In other words, if someone notices that they are aroused cognitively, they will become physiologically aroused and vice versa [12]. It is suggested that cognitive arousal seems to be a type of physiological arousal, although being an arousal of central nervous system (CNS) rather than autonomic nervous system (ANS) [11]. One possible explanation for this finding is that a subjective rather than an objective measure was employed for somatic arousal (i.e. PSAS) and with respect to this idea that somatic arousal is better operationalized in terms of physiological scales [11], this may reduce the proportion of the somatic arousal in prediction of insomnia severity.
In recent years, metacognition has received considerable attention in the insomnia literature. As cited by Wells (2000), when there is a threatening discrepancy between the perceived self-state and the ideal state, Self-Regulatory Executive Function (S-REF) is activated [47]. In the context of insomnia, it seems this threatening difference is being awake when the desired aim of the
individual is sleeping. Therefore, it is proposed that at the automatic processing level, physical, cognitive and external cues are threatening. In other words, for insomniacs whose desired goal is sleeping, wakefulness could be an important threat at bedtime [35].The obtained results showed that there is a positive correlation between metacognition and insomnia symptoms (r=0.47). Waine et al [35] found that primary insomniac patients score significantly higher than normal sleepers on Metacognitions Questionnaire –Insomnia. In addition, there were significant associations between Metacognitions Questionnaire –Insomnia and both sleep onset latency and Pittsburgh Sleep Quality Index scores. Thus, the current study confirmed the role of metacognitive beliefs in insomnia and this finding is consistent with previous studies that indicated the components of SRE-F in insomnia patients [22, 21]. But the current study is new with regard to showing that this relationship also exists in a nonclinical population.
Although worry was significantly correlated with insomnia symptoms (r=0.35), it was finally excluded from the predictive model of insomnia. It is worth to note that a recent study examined rumination in relation with worry in insomnia patients [48]. In this study, results of MANOVA showed no significant effect of worry, although there were significant differences on several sleep logs in subjects with high and low ruminations. One possibility that is mentioned by these authors is that previous measures have been capturing rumination rather than worry and previous researchers have misattributed sleep difficulties to worry rather than rumination. The cognitive content of rumination is focused on making attributions for disturbed mood and symptoms such as concentration difficulties [49], whereas worry may be more focused on future, negative consequences of the current mood state [50]. However, another explanation that seems more acceptable is that PSWQ measures general worry and is not designed to capture worries that are specific to sleep [48]. It is not impossible that such similar points affect the proportion of worry in predicting insomnia in the current study. The obtained results showed that there is a positive correlation between anxiety symptoms and insomnia severity (r=0.38), but anxiety was excluded from the final model. One study by Ohayon & Roth [8] showed that when insomnia and anxiety disorders were considered together, insomnia often appeared in the same time (>38%) or after (>34%) the anxiety disorder. Moreover, as cited by Jansson-Frojmark and Lindblom [9], associations between anxiety and insomnia could be biased towards stronger relationships in the patient population, which may not be representative of the population as a whole sample. Thus, given that the participants were a nonclinical population, it is not surprising that anxiety was excluded from the predicting model. Moreover, the means of insomnia severity and anxiety according to guidelines of ISI and DASS21 are not at a severe level (22-28= severe clinical insomnia; 15-19= severe anxiety) in the population under study and this may reduce the correlation between insomnia severity and anxiety symptoms.
Family and cultural attitudes and beliefs are strongly influential whether or not sleeping behavior is perceived as problematic [51]. It is shown that decisions parents make regarding their children’s sleep are influenced by various factors, such as economic conditions, family size, available space, and even climate conditions [52]. Iran is a pluralistic society with many unique subcultures; such a cultural diversity may lead to variations in sleep-wake patterns and sleep habits. But, in general, the Iranian culture emphasizes the development of interdependence and family closeness. Most of the participants of this research were living in dormitory (60.3%) and one may expect to see more severe sleep problems because of difficulty in sleeping with others in a room. However, with regard to Iranian collective culture, living in dormitory did not influence sleep much negatively. In addition, Iranians live in a religious society and some recommended religious instructions (for example reading Quran or some prayer) that are followed by Iranians before going to bed may help them with reducing their anxiety and facilitate their sleep. This is an interesting issue that can be examined in other studies. Replication of previous relationship between variables in the present study showed that these relationships also exist in a different culture. However, in order to develop a more effective treatment, it is important to examine the role of cultural processes in sleep regulation and psychopathology; future studies are recommended to consider the influence of Iranian culture on sleep problems.
The obtained results must be interpreted with respect to some limitations. The current research was a cross-sectional (a class of research methods that involve observation of all of a population, or a representative subset, at one specific point in time) study. With respect to this aspect of the study, no specific causality between insomnia symptoms, cognitive arousal, dysfunctional beliefs about sleep, metacognitive beliefs about sleep, and depressive symptoms could be precluded. Future studies are recommended to address this limitation by a longitudinal design. Another issue which relates to the population studied in this research (i.e. university students who were generally healthy and well-educated), is the limitation in generalizability of the obtained results to the Iranian young adult population. In addition, a reasonable concern is that university students are not representative of treatment-seeking individuals [53], though clinical sleep disorders are common in young adults [54]. Although it is common to employ self-reports in insomnia researches and it is found that self-report measures of insomnia are generally highly correlated with objective measures [55], it does introduce the possibility of reporting bias.
IMPLICATIONS AND CONCLUSION
Although many researchers have studied the relationship between similar variables and insomnia symptoms, according to the current search, no study has considered all these variables together to date. As a conclusion, the results of the current study were consistent with those of previous studies in regard with the role of cognitive arousal on insomnia. Influence of dysfunctional beliefs about sleep on insomnia has been indicated in Harvey’s model [12]. It is proposed that unhelpful beliefs about sleep and the benefits of worry are likely to fuel excessive cognitive activity. In addition, the evidence that metacognitive beliefs about sleep predicted insomnia suggests the possibility of new models of insomnia that includes such factors. Including metacognitive beliefs specific to insomnia along with other variables to determine its priority among other components was in the interest of the current study.
The finding that depressive symptoms were a predictor of insomnia endorses the role of emotional variables in insomnia. According to the obtained results, cognitive variables are the most important variables in predicting insomnia. Given the current models of insomnia [12] which consider dysfunctional beliefs as important alongside a wide range of components, the findings of the current study may be interpreted as relatively surprising as the results indicated that cognitive factors were more strongly related to insomnia symptoms than other factors. The authors of the current study did not conduct any structural interview for excluding participants with mood and anxiety disorders and just used self-reports. It was expected that similar to previous studies, depression and anxiety have a primary role in predicting insomnia severity but the present study showed that cognitive and metacognitive factors play a more important role in insomnia severity. One reason to this finding may be that a nonclinical population was used in this study. This study also provided evidence of the need for further research on the influence of cognitive arousal, dysfunctional beliefs, metacognitive beliefs and depression on the insomnia. In total, replications of the current study with treatment-seeking patients or clinical populations are useful.
Finally, the authors of the current paper would like to express their appreciation to Dr. Colin A. Espie and Dr. Niall M. Broomfield who helped and supported the authors of this paper with their permission for using MCQ-I.
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Table 1 Descriptive statistics for demographic variables
Gender
Residency status
Group
Frequency
Percent
male
166
41.5
female
234
58.5
dormitory
241
60.3
with parents
129
32.3
personal home
30
7.5
Undergraduate
179
44.8
Master of Science
72
18.0
PhD
26
6.5
Medical student
123
30.8
single
366
91.5
married
34
8.5
medicine
152
38
rehabilitation
98
24.5
nursing and midwifery
91
22.8
management and medical information
59
14.8
Academic levels
Marital status
School
Table 2 Means and standard deviations of study variables Variable
M
SD
Depression (DASS-D)
9.57
8.95
Anxiety (DASS-A)
7.92
7.79
Worry (PSWQ)
43.78
11.10
Cognitive arousal (PSAS-C)
19.89
5.71
Somatic arousal (PSAS-S)
13.10
5.38
Dysfunctional beliefs about sleep (DBAS)
5.21
2.03
Metacognitive beliefs about sleep (MCQ-I)
116.35
26.42
Insomnia severity (ISI)
9.79
5.03
Note: DASS-D= Depression, Anxiety and Stress Scale- depression subscale; DASS-A= Depression, Anxiety and Stress Scale- Anxiety subscale; PSWQ = Penn State Worry Questionnaire; PASA-C= Pre-Sleep Arousal Scalecognitive subscale; PSAS-S= Pre-Sleep Arousal Scale- somatic subscale; DBAS-10= Dysfunctional Beliefs and Attitudes about Sleep Scale; MCQ-I= Metacognitions Questionnaire –Insomnia; ISI= Insomnia Severity Index.
Table 3
DASS-D
1
DASS-A
0.67*
1
PSWQ
0.48*
0.50*
1
PASA-C
0.39*
0.40*
0.47* 1
PSAS-S
0.41*
0.60*
0.42* 0.44*
1
DBAS-10
0.25*
0.35*
0.31* 0.31*
0.43*
1
MCQ-I
0.35*
0.30*
0.41* 0.53*
0.40*
0.42*
1
ISI
0.37*
0.38*
0.35* 0.58*
0.42*
0.42*
0.47*
ISI
MCQ-I
DBAS-10
PSAS-S
PSAS-C
PSWQ
DASS-D
variables
DASS-A
Intercorrelations for variables
1
Note: DASS-D= Depression, Anxiety and Stress Scale- depression subscale; DASS-A= Depression, Anxiety and Stress Scale- Anxiety subscale; PSWQ = Penn State Worry Questionnaire; PASA-C= Pre-Sleep Arousal Scale- cognitive subscale; PSAS-S= Pre-Sleep Arousal Scale- somatic subscale; DBAS-10= Dysfunctional Beliefs and Attitudes about Sleep Scale; MCQ-I= Metacognitions Questionnaire –Insomnia; ISI= Insomnia Severity Index. *p<0.001
Table 4 Standard multiple regression statistics for ISI with independent variables B
β
t
sig
-3.752
0.001
Intercept
-3.486
Cognitive arousal
0.352
0.400
8.546
0.001
Dysfunctional beliefs about 0.055 sleep
0.224
5.285
0.001
Metacognitive beliefs about sleep
0.024
0.126
2.629
0.009
depression
0.062
0.111
2.626
0.009
R R2 Adjusted R2
0.654* 0.428 0.422*
F
73.918
DF
(4, 395)
*p<0.001
Prediction of Insomnia Severity based on Cognitive, Metacognitive and Emotional Variables in College Students Hoda Doos Ali Vand M.A., Banafsheh Gharraee PhD., Ali-Asghar Asgharnejad Farid PhD., MirFarhad Ghaleh Bandi MD.
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Cite this article as: Hoda Doos Ali Vand M.A., Banafsheh Gharraee PhD., Ali-Asghar Asgharnejad Farid PhD., MirFarhad Ghaleh Bandi MD., Prediction of Insomnia Severity based on Cognitive, Metacognitive and Emotional Variables in College Students, Explore, http://dx.doi.org/10.1016/j.explore.2014.04.005 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Prediction of Insomnia Severity based on Cognitive, Metacognitive and Emotional Variables in College Students
Hoda Doos Ali Vand1, Banafsheh Gharraee2*, Ali-Asghar Asgharnejad Farid 3, MirFarhad Ghaleh Bandi 4
1
M.A. in Clinical Psychology, Tehran Institute of Psychiatry – Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences , Department of Clinical Psychology, Tehran, I. R. Iran.
2
PhD. in Clinical Psychology, Assistant Prof of Mental Health Research Center, Tehran Institute of Psychiatry –Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences , Department of Clinical Psychology, Tehran, I. R. Iran.
3
PhD. in Clinical Psychology, Assistant Prof of Mental Health Research Center, Tehran Institute of Psychiatry –Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences , Department of Clinical Psychology, Tehran, I. R. Iran.
4
MD. in Psychiatry, Associate Prof of Mental Health Research Center, Tehran Institute of Psychiatry – Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences , Department of Psychiatry, Tehran, I. R. Iran.
*Corresponding Author: Assistant Prof Mental Health Research Center, Tehran Institute of Psychiatry – Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences, Department of Clinical Psychology, Tehran, I. R. Iran., P.O. Box 1445613111, Email: [email protected] * Correspondence should be sent to: Banafsheh gharaee, Ph.D, University of Medical Sciences & Health Services, Psychiatry Institute, Department of Clinical Psychology, Tehran, Iran P. O. Box 1445613111
Tel: 00989123386397 Fax: 00982166551575 Email: [email protected]
Prediction of Insomnia Severity based on Cognitive, Metacognitive and Emotional Variables in College Students
Abstract Objective: Insomnia is the most common sleep disorder whose origin is attributed to various variables. The current study aims to predict the symptoms of insomnia by investigating some of its predictors.
Methods: Numerous variables such as depression and anxiety symptoms, worry, pre-sleep arousal (cognitive arousal and somatic arousal), dysfunctional cognitions and metacognitive beliefs about sleep were assessed as insomnia predictors. 400 students of Tehran University of Medical Sciences completed Depression- Anxiety- Stress Scale (DASS), Penn State Worry Questionnaire (PSWQ), Pre-Sleep Arousal Scale (PSAS), Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-10), Metacognitions Questionnaire-insomnia (MCQ-I), and Insomnia Severity Index (ISI).
Results: All variables were significantly correlated with insomnia symptoms (P<0.001). Stepwise multiple regression analysis suggested a predictive model for insomnia including cognitive arousal, dysfunctional beliefs about sleep, metacognitive beliefs about sleep, and depressive symptoms.
Conclusions: The findings underline the significant role of cognitive and metacognitive variables for predicting insomnia symptoms. Moreover, the results suggest that metacognitive beliefs about sleep may need to be considered as a significant component in the context of insomnia.
Keywords: Insomnia, Depression, Anxiety, Worry, Arousal, Cognition, Metacognition.
INTRODUCTION Insomnia is defined as difficulty in falling asleep, difficulty in remaining asleep, early morning awakening and/or non-restorative sleep, associated with daytime consequences [1]. In the last decade, national and international studies have consistently shown that insomnia is a common problem in the general population of many countries [2-4]. It is estimated that about one-third of the general population present at least one of the insomnia symptoms and when daytime consequences of insomnia are included, the prevalence will be between 9% and 15% [5]. Insomnia is associated with varieties of psychiatric conditions especially depression and anxiety [6-8] and it seems that there is a bi-directional relationship between these variables and insomnia [9] .
Over the years, several models have been presented in the context of insomnia helping researchers to understand the variables that cause and perpetuate this condition [10-13]. These models identify persistent insomnia as a problem with several dimensions and it is proposed that many mechanisms contribute to its maintenance reciprocally. Although there are differences between these models, all of them consider physiological, cognitive, affective, and behavioral factors as prominent variables in developing insomnia [14].
It has been documented that cognitive processes play a significant role in insomnia and other disorders with concomitant sleep disruption [15, 16]. It is stated that dysfunctional beliefs and attitudes toward sleep are the most researched cognitive phenomenon in the context of insomnia. Five important classes of unhelpful beliefs about sleep have been proposed: misconceptions about the causes of insomnia, misattributions or amplifications of the consequences of insomnia, unrealistic sleep expectations, diminished perception of control over sleep, and faulty beliefs about sleep promoting practices [10]. Another cognitive phenomenon is pre-sleep worry that is viewed as an important variable preventing the individual from falling asleep. It has been shown that people with insomnia frequently experience unpleasant intrusive thoughts and excessive and uncontrollable worry as a disturbing factor during the pre-sleep period [17].
There has been a surge of interest in the role of arousal as an integrative approach in understanding insomnia (especially primary insomnia (PI) or psychophysiological insomnia). This perspective assumes that psychological and physiological components play a reciprocal role in development and maintenance of chronic insomnia. It is proposed that arousal is expressed in terms of somatic, cognitive and cortical activation [18].
In recent years, some studies have provided evidence supporting the idea that metacognitive beliefs and strategies play an important role in primary insomnia. “Metacognition can be defined as internal cognitive factors that control, monitor and appraise thinking. It can be subdivided into metacognitive knowledge (e.g., I must worry in order to cope), experience (e.g., a feeling of knowing) and strategies (e.g., ways of controlling thoughts and protecting beliefs)” [19]. It is shown that insomniac patients selectively attend to salient internal and external threat cues [20]. Harvey (2003) found that primary insomniac patients endorse more positive belief statements about worry [21]. Moreover, it is demonstrated that using thought control strategies, for instance worry, reappraisal, thought suppression and punishment, is very common in people with primary insomnia [22]. In addition, hardly do they try to sleep and tend to control sleep onset anxiously [23] .
Medical students is a specific group that suffers more from insomnia; they have thus received special attention in insomnia researches [24]. To have an appropriate description of the profile of individuals with insomnia, it is helpful to examine several variables simultaneously in a specific population. Investigating correlates of insomnia in individuals with less severe insomnia rather than treatment-seeking individuals can help with developing effective early intervention programs to prevent the development of chronic insomnia and the pursuant mental health disorders [25].
According to these issues, the first objective of the present study is to determine relations of some important variables with insomnia symptoms in Iranian students. Specially, examining the relationship between metacognitions and insomnia symptoms in a nonclinical population was in authors’ interest. The second objective is to determine the priority of these variables in prediction of insomnia severity. According to the search conducted by the authors, no study in insomnia literature has examined all of these variables together. The current study is new with regard to including metacognitions along with other variables to determine its priority among other components. In this study, depressive and anxiety symptoms, worry, pre-sleep arousal (cognitive and somatic arousal), dysfunctional beliefs about sleep and metacognitive beliefs about sleep are assessed as predictors of insomnia severity.
METHODS Participants Multistage cluster sampling was used to select a representative population from Tehran University of Medical Sciences. At first, 4 schools including medicine; nursing and midwifery; rehabilitation; management and medical information were selected randomly. Then, in every school, according to the proportion of students in any academic level, some classes were selected randomly and questionnaires were distributed among the students. According to community size, 430 medical students of Tehran University were invited to participate.
Procedures The current study was carried out as a correlational retrospective study in which insomnia symptoms were the criterion variable and depressive and anxiety symptoms, pre-sleep arousal, dysfunctional beliefs and attitudes about sleep and metacognition beliefs related to insomnia were the prediction variables. The first pages of the questionnaires informed participants of the purpose and nature of the study. In addition, this section assured them of their anonymity and asked participants to provide informed consent by marking a statement before completing other questionnaires. In addition to the six published scales and basic demographic information, questions relating to mental or physical disorder, hypnotic use, and work shift were also included. Participants were asked whether they had a medical or psychiatric disorder which, according to their physician or psychiatrist, could cause insomnia. If the response was yes, they would be asked to explain more about that problem. In addition, participants who took hypnotic drugs or had work shifts at night were excluded. The study was approved by the ethical and research committee of Tehran University of Medical Sciences.
Measures Depression, Anxiety and Stress Scale (DASS-21): DASS-21 is a 4-point Likert scale (0=did not apply to me at all; 3=applied to me very much, or most of the time) with three factors that measure: (1) three negative emotional states of depression (seven items); (2) anxiety (seven items); and (3) stress (seven items). It is a short version of the DASS 42-item scale [26, 27]. DASS-
21 is of great validity and reliability among Iranian specialists. Validity coefficients are reported as 0.81 for depression, 0.78 for anxiety, 0.80 for mental pressure and 0.82 for total scale. Internal consistency coefficients are also reported as 0.85 for depression factor, 0.75 for anxiety, and 0.87 for mental pressure. Test-retest reliability of the total scale for 3 weeks is reported as 0.82 [28]. In this study, depression and anxiety subscales of DASS-21 were used for measuring depressive and anxiety symptoms. Penn State Worry Questionnaire (PSWQ): This self-report questionnaire consists of 16 items. It is designed to measure the excessiveness, duration and uncontrollability of worry as experienced in GAD patients. The PSWQ is of high reliability, adequate temporal stability and substantial validity in the assessment of trait worry [29-30].PSWQ has exhibited good psychometric properties in Iran. Cronbach alpha equals 0.88 for the total questionnaire, and test-retest reliability of the total scale for 1 month is reported as 0.79 [31]. Pre-Sleep Arousal Scale (PSAS): PSAS is a self-report scale containing 16 items. This fivepoint Likert scale (1, “not at all” to 5, “extremely”) has two subscales (somatic and cognitive arousal) [32]. Internal consistency of the PSAS has been adequate (α=.76 and .81 for the somatic and cognitive scales, respectively), and high PSAS scores have been associated with sleep onset difficulties [33].This scale was translated into Persian for the purpose of the study. Results supported the internal consistency (α=.72 and .84 for the somatic and cognitive scales, respectively) and its concurrent validity with Pittsburgh Sleep Quality Index (PSQI) (r=.71, P< .01). Test-retest reliability of the total scale for 2 weeks in 30 participants was .88 (P<.01).
Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-10): This scale assesses sleeprelated beliefs and is the short version of DBAS-30 [34, 10]. Each statement contains a 10centimeter horizontal line with poles labeled ‘‘strongly agree’’ and ‘‘strongly disagree’’. The total score is based on the average score of all items and ranges from 0 to 10. Studies have demonstrated DBAS-10 to be a satisfactory instrument [34].This scale was translated into Persian for the purpose of the study. Results supported the internal consistency (α=.91) and its concurrent validity with PSQI (r=.45, P< .05). Test-retest reliability of total scale for 2 weeks in 30 participants was .83 (P<.01).
Metacognitions Questionnaire–Insomnia (MCQ-I): The Metacognitions Questionnaire – Insomnia (MCQ-I) is a 60-item and a self-report measure that assesses metacognitive beliefs in insomnia. It is demonstrated that primary insomniac patients score significantly higher than normal sleepers on MCQ-I. The MCQ-I has been correlated significantly with MCQ-30. This questionnaire is of adequate validity and reliability [35].This scale was translated into Persian for the purpose of the study. Results supported the internal consistency (α=.95) and its concurrent
validity with MCQ-30 (r=.38, P< .05). Test-retest reliability of total scale for 2 weeks in 30 participants was .87 (P<.01).
Insomnia Severity Index (ISI): ISI was employed for the assessment of insomnia severity in the population under study [36]. This questionnaire has seven items that measure: (1) severity of sleep onset; (2) sleep maintenance and early morning waking; (3) satisfaction with current sleeping patterns; (4) interference with daily functioning; and (5) noticeability of sleep impairment and the associated degree of worry and anxiety. Participants were asked to rate their perception of each ISI item on a 5-point scale (0=not at all; 4=very much). Scores range between 0 and 28. Higher scores indicate a high perception of insomnia. This scale was translated into Persian for the purpose of the study. Results showed that this scale has satisfactory internal consistency (α=.81) and test-retest reliability for 2 weeks in 30 participants was .72 (r=.72, P<.01). Its concurrent validity with PSQI was .80 (P< .01). Analysis The data were first summarized to provide descriptive statistics. The correlation between variables was analyzed with Pearson correlations. T-tests were used to test for gender and marital status differences on insomnia severity. To examine differences on insomnia severity between the three residency status groups (dormitory, with parents, personal home) and between the four academic level groups, analysis of variance was used. Stepwise multiple regression analysis was conducted with the aim of identifying independent predictors of insomnia severity, and the relative importance of specific predictors of insomnia. Variables that have been shown in previous studies to correlate with insomnia (depression, anxiety, worry, pre-sleep arousal, dysfunctional beliefs about sleep, and metacognitive beliefs about sleep) were used as independent variables in the regression. All data were analyzed using the SPSS 18.0 software package. Table 1 show the descriptive statistics of the demographic variables and table 2 shows means and standard deviations of all variables in this study.
RESULTS 6.9% of students did not return their questionnaires and were excluded from the study. Only 1% of the population had medical or psychiatric disorder and were excluded from the study. Finally, a total of 400 students (166 male, 234 female) composed our study population. Participants were students between the ages of 20 and 46. Of these participants, 44.8% were undergraduate students (N=179), 18% were master students (N=72), 6.5% were Ph.D students (N=26), and 30.8% were medical students (N=123). The mean age was 22.18 (SD=4.06 years). Moreover, 60.3% (N=241) were living in dormitory, 32.3% (N=129) were living with their parents and 7.5% (N=30) had their own private houses. 91.5% (N=366) were single and 8.5% (N=34) were married. The participants who did not return their questionnaires did not differ significantly from those who returned their questionnaires.
ANOVA was used to determine whether there were any statistical differences between different gender groups as well as groups of different marital statuses in insomnia severity. The results of ANOVA showed that different gender groups (F = 10.56, P < 0.001) as well as groups belonging to different marital statuses (F= 6.765, P<0.05) experienced significantly different severities of insomnia which was higher in females and in singles than males and the married.
To determine whether individuals with different residency status and academic levels exhibited statistical differences of insomnia severity, analysis of variance with Tukey post hoc test was employed. Analysis of variance showed that there were significant differences of insomnia severity for individuals with different residency statuses (F = 4.31, P<0.01), but no significant differences of insomnia severity between individuals of different academic levels (F = 1.79, P = 0.14). Post hoc tests revealed that pairwise differences among the means were significant for
individuals living in dormitory and the ones living with parents (P< 0.05) as well as the ones living in dormitory and having their own private house (P<0.05) and individuals living in dormitory had higher mean scores on the ISI. Table 3 presents the Pearson correlations between predictor variables and severity of insomnia. Inspection of the correlation matrix revealed that DASS-21, PSWQ, PSAS, DBAS-10 and MCQI were correlated significantly with ISI scores. The strongest correlation was between cognitive arousal and ISI scores. To examine whether depressive and anxiety symptoms, worry, pre-sleep arousal (cognitive and somatic arousal), dysfunctional beliefs about sleep and metacognitive beliefs about sleep were related to insomnia symptoms, stepwise regression analyses were utilized. The following variables were entered as predictor variables: dysfunctional beliefs about sleep (DBAS-10), metacognitive beliefs about sleep (MCQ-I), worry (PSWQ), cognitive arousal (PSAS1), somatic arousal (PSAS2), anxiety (DASS-A), depression (DASS-D). Table 4 shows the results of the hierarchical regression analyses.
As shown in Table 4, R (for regression) was significantly different from zero [F=73.91, P<0.001]. Cognitive arousal, dysfunctional beliefs about sleep, metacognitive beliefs about sleep and depressive symptoms contributed significantly to the prediction of insomnia severity as indicated by the β weights displayed in Table 4.
DISCUSSION The first objective of the present study was to determine the correlation of depressive and anxiety symptoms, worry, pre-sleep arousal (cognitive and somatic arousal), dysfunctional beliefs about sleep, and metacognitive beliefs about sleep with insomnia severity. The results showed that all predictive variables were significantly correlated with insomnia symptoms. The second objective of the present study was to determine the priority of these variables in predicting insomnia severity. There was evidence that cognitive arousal, dysfunctional beliefs about sleep, metacognitive beliefs about sleep and depressive symptoms contributed significantly to the prediction of insomnia severity. Cognitive arousal accounted for the greatest degree of variance in the prediction of insomnia symptoms followed by dysfunctional beliefs about sleep, metacognitive beliefs about sleep and depressive symptoms. In total, these variables accounted for 42% of variance of insomnia symptoms. However, anxiety, worry and somatic arousal were excluded from the model.
This study, similar to the previous studies [37-38], revealed a positive correlation between depressive symptoms and insomnia (r=0.37). But the weight of depressive symptoms in predicting insomnia was low. There is evidence suggesting bidirectional relationship between depression and insomnia [9]. A review study [39] showed that insomnia had predictive value for future depression. Thus, although there is a relationship between these two variables, the association does not seem to be a simple causal relationship. In one study that depression was the first variable in predicting insomnia, it was considered along with medical conditions [40]. In the current study, depression was considered along with cognitive and metacognitive variables and this may reduce the proportion of depression in predicting insomnia. Moreover, the means of depression and insomnia severity according to guidelines of ISI and DASS-21 are not at a severe level (22-28= severe clinical insomnia; 21-27=severe depression) in the population of the current study and this may account for the low correlation between insomnia severity and depressive
symptoms. Our study showed that insomnia severity is related with depressive symptoms in nonclinical students with a different culture.
The relationship between dysfunctional beliefs about sleep and insomnia symptoms is supported in the current study. This finding is consistent with other studies that showed sleep-disruptive beliefs playing an important role in sleep difficulties [41-43]. People with insomnia indicate dysfunctional beliefs and attitudes about sleep frequently. These unhelpful cognitions are less flexible and, thus, are more maladaptive than the sleep-related beliefs of normal sleepers [44]. Cognitive models of insomnia suggest a central role for such disruptive beliefs about sleep in insomnia [12]. However, there may be a bidirectional relationship between these two variables and dysfunctional beliefs may be a result of chronic poor sleep.
Results of the current study showed that pre-sleep arousal can predict severity of insomnia. Despite the fact that both cognitive and somatic arousal had a positive significant correlation with insomnia symptoms, cognitive arousal was a more important variable than somatic arousal in predicting insomnia symptoms and somatic arousal was excluded from the model. In total, it is shown that cognitive arousal has a stronger correlation than somatic arousal with insomnia. Lichstein and Rosenthal [45] found that insomniacs attributed their difficulties in sleeping to cognitive arousal (i.e., the mind being very active at bedtime, thinking, worrying, planning, analyzing, difficulty in controlling thoughts) rather than somatic arousal (i.e., being aware of one's body as restless, shifting, sweaty, etc.). It is revealed that although both cognitive and somatic arousal are significantly associated with sleep disturbances, the strongest association was between cognitive arousal and sleep difficulties [46].On the other hand, it seems that cognition and physiology are not two completely opposing systems, but they should be considered as simultaneous systems. In other words, if someone notices that they are aroused cognitively, they will become physiologically aroused and vice versa [12]. It is suggested that cognitive arousal seems to be a type of physiological arousal, although being an arousal of central nervous system (CNS) rather than autonomic nervous system (ANS) [11]. One possible explanation for this finding is that a subjective rather than an objective measure was employed for somatic arousal (i.e. PSAS) and with respect to this idea that somatic arousal is better operationalized in terms of physiological scales [11], this may reduce the proportion of the somatic arousal in prediction of insomnia severity.
In recent years, metacognition has received considerable attention in the insomnia literature. As cited by Wells (2000), when there is a threatening discrepancy between the perceived self-state and the ideal state, Self-Regulatory Executive Function (S-REF) is activated [47]. In the context of insomnia, it seems this threatening difference is being awake when the desired aim of the
individual is sleeping. Therefore, it is proposed that at the automatic processing level, physical, cognitive and external cues are threatening. In other words, for insomniacs whose desired goal is sleeping, wakefulness could be an important threat at bedtime [35].The obtained results showed that there is a positive correlation between metacognition and insomnia symptoms (r=0.47). Waine et al [35] found that primary insomniac patients score significantly higher than normal sleepers on Metacognitions Questionnaire –Insomnia. In addition, there were significant associations between Metacognitions Questionnaire –Insomnia and both sleep onset latency and Pittsburgh Sleep Quality Index scores. Thus, the current study confirmed the role of metacognitive beliefs in insomnia and this finding is consistent with previous studies that indicated the components of SRE-F in insomnia patients [22, 21]. But the current study is new with regard to showing that this relationship also exists in a nonclinical population.
Although worry was significantly correlated with insomnia symptoms (r=0.35), it was finally excluded from the predictive model of insomnia. It is worth to note that a recent study examined rumination in relation with worry in insomnia patients [48]. In this study, results of MANOVA showed no significant effect of worry, although there were significant differences on several sleep logs in subjects with high and low ruminations. One possibility that is mentioned by these authors is that previous measures have been capturing rumination rather than worry and previous researchers have misattributed sleep difficulties to worry rather than rumination. The cognitive content of rumination is focused on making attributions for disturbed mood and symptoms such as concentration difficulties [49], whereas worry may be more focused on future, negative consequences of the current mood state [50]. However, another explanation that seems more acceptable is that PSWQ measures general worry and is not designed to capture worries that are specific to sleep [48]. It is not impossible that such similar points affect the proportion of worry in predicting insomnia in the current study. The obtained results showed that there is a positive correlation between anxiety symptoms and insomnia severity (r=0.38), but anxiety was excluded from the final model. One study by Ohayon & Roth [8] showed that when insomnia and anxiety disorders were considered together, insomnia often appeared in the same time (>38%) or after (>34%) the anxiety disorder. Moreover, as cited by Jansson-Frojmark and Lindblom [9], associations between anxiety and insomnia could be biased towards stronger relationships in the patient population, which may not be representative of the population as a whole sample. Thus, given that the participants were a nonclinical population, it is not surprising that anxiety was excluded from the predicting model. Moreover, the means of insomnia severity and anxiety according to guidelines of ISI and DASS21 are not at a severe level (22-28= severe clinical insomnia; 15-19= severe anxiety) in the population under study and this may reduce the correlation between insomnia severity and anxiety symptoms.
Family and cultural attitudes and beliefs are strongly influential whether or not sleeping behavior is perceived as problematic [51]. It is shown that decisions parents make regarding their children’s sleep are influenced by various factors, such as economic conditions, family size, available space, and even climate conditions [52]. Iran is a pluralistic society with many unique subcultures; such a cultural diversity may lead to variations in sleep-wake patterns and sleep habits. But, in general, the Iranian culture emphasizes the development of interdependence and family closeness. Most of the participants of this research were living in dormitory (60.3%) and one may expect to see more severe sleep problems because of difficulty in sleeping with others in a room. However, with regard to Iranian collective culture, living in dormitory did not influence sleep much negatively. In addition, Iranians live in a religious society and some recommended religious instructions (for example reading Quran or some prayer) that are followed by Iranians before going to bed may help them with reducing their anxiety and facilitate their sleep. This is an interesting issue that can be examined in other studies. Replication of previous relationship between variables in the present study showed that these relationships also exist in a different culture. However, in order to develop a more effective treatment, it is important to examine the role of cultural processes in sleep regulation and psychopathology; future studies are recommended to consider the influence of Iranian culture on sleep problems.
The obtained results must be interpreted with respect to some limitations. The current research was a cross-sectional (a class of research methods that involve observation of all of a population, or a representative subset, at one specific point in time) study. With respect to this aspect of the study, no specific causality between insomnia symptoms, cognitive arousal, dysfunctional beliefs about sleep, metacognitive beliefs about sleep, and depressive symptoms could be precluded. Future studies are recommended to address this limitation by a longitudinal design. Another issue which relates to the population studied in this research (i.e. university students who were generally healthy and well-educated), is the limitation in generalizability of the obtained results to the Iranian young adult population. In addition, a reasonable concern is that university students are not representative of treatment-seeking individuals [53], though clinical sleep disorders are common in young adults [54]. Although it is common to employ self-reports in insomnia researches and it is found that self-report measures of insomnia are generally highly correlated with objective measures [55], it does introduce the possibility of reporting bias.
IMPLICATIONS AND CONCLUSION
Although many researchers have studied the relationship between similar variables and insomnia symptoms, according to the current search, no study has considered all these variables together to date. As a conclusion, the results of the current study were consistent with those of previous studies in regard with the role of cognitive arousal on insomnia. Influence of dysfunctional beliefs about sleep on insomnia has been indicated in Harvey’s model [12]. It is proposed that unhelpful beliefs about sleep and the benefits of worry are likely to fuel excessive cognitive activity. In addition, the evidence that metacognitive beliefs about sleep predicted insomnia suggests the possibility of new models of insomnia that includes such factors. Including metacognitive beliefs specific to insomnia along with other variables to determine its priority among other components was in the interest of the current study.
The finding that depressive symptoms were a predictor of insomnia endorses the role of emotional variables in insomnia. According to the obtained results, cognitive variables are the most important variables in predicting insomnia. Given the current models of insomnia [12] which consider dysfunctional beliefs as important alongside a wide range of components, the findings of the current study may be interpreted as relatively surprising as the results indicated that cognitive factors were more strongly related to insomnia symptoms than other factors. The authors of the current study did not conduct any structural interview for excluding participants with mood and anxiety disorders and just used self-reports. It was expected that similar to previous studies, depression and anxiety have a primary role in predicting insomnia severity but the present study showed that cognitive and metacognitive factors play a more important role in insomnia severity. One reason to this finding may be that a nonclinical population was used in this study. This study also provided evidence of the need for further research on the influence of cognitive arousal, dysfunctional beliefs, metacognitive beliefs and depression on the insomnia. In total, replications of the current study with treatment-seeking patients or clinical populations are useful.
Finally, the authors of the current paper would like to express their appreciation to Dr. Colin A. Espie and Dr. Niall M. Broomfield who helped and supported the authors of this paper with their permission for using MCQ-I.
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Table 1 Descriptive statistics for demographic variables
Gender
Residency status
Group
Frequency
Percent
male
166
41.5
female
234
58.5
dormitory
241
60.3
with parents
129
32.3
personal home
30
7.5
Undergraduate
179
44.8
Master of Science
72
18.0
PhD
26
6.5
Medical student
123
30.8
single
366
91.5
married
34
8.5
medicine
152
38
rehabilitation
98
24.5
nursing and midwifery
91
22.8
management and medical information
59
14.8
Academic levels
Marital status
School
Table 2 Means and standard deviations of study variables Variable
M
SD
Depression (DASS-D)
9.57
8.95
Anxiety (DASS-A)
7.92
7.79
Worry (PSWQ)
43.78
11.10
Cognitive arousal (PSAS-C)
19.89
5.71
Somatic arousal (PSAS-S)
13.10
5.38
Dysfunctional beliefs about sleep (DBAS)
5.21
2.03
Metacognitive beliefs about sleep (MCQ-I)
116.35
26.42
Insomnia severity (ISI)
9.79
5.03
Note: DASS-D= Depression, Anxiety and Stress Scale- depression subscale; DASS-A= Depression, Anxiety and Stress Scale- Anxiety subscale; PSWQ = Penn State Worry Questionnaire; PASA-C= Pre-Sleep Arousal Scalecognitive subscale; PSAS-S= Pre-Sleep Arousal Scale- somatic subscale; DBAS-10= Dysfunctional Beliefs and Attitudes about Sleep Scale; MCQ-I= Metacognitions Questionnaire –Insomnia; ISI= Insomnia Severity Index.
Table 3
DASS-D
1
DASS-A
0.67*
1
PSWQ
0.48*
0.50*
1
PASA-C
0.39*
0.40*
0.47* 1
PSAS-S
0.41*
0.60*
0.42* 0.44*
1
DBAS-10
0.25*
0.35*
0.31* 0.31*
0.43*
1
MCQ-I
0.35*
0.30*
0.41* 0.53*
0.40*
0.42*
1
ISI
0.37*
0.38*
0.35* 0.58*
0.42*
0.42*
0.47*
ISI
MCQ-I
DBAS-10
PSAS-S
PSAS-C
PSWQ
DASS-D
variables
DASS-A
Intercorrelations for variables
1
Note: DASS-D= Depression, Anxiety and Stress Scale- depression subscale; DASS-A= Depression, Anxiety and Stress Scale- Anxiety subscale; PSWQ = Penn State Worry Questionnaire; PASA-C= Pre-Sleep Arousal Scale- cognitive subscale; PSAS-S= Pre-Sleep Arousal Scale- somatic subscale; DBAS-10= Dysfunctional Beliefs and Attitudes about Sleep Scale; MCQ-I= Metacognitions Questionnaire –Insomnia; ISI= Insomnia Severity Index. *p<0.001
Table 4 Standard multiple regression statistics for ISI with independent variables B
β
t
sig
-3.752
0.001
Intercept
-3.486
Cognitive arousal
0.352
0.400
8.546
0.001
Dysfunctional beliefs about 0.055 sleep
0.224
5.285
0.001
Metacognitive beliefs about sleep
0.024
0.126
2.629
0.009
depression
0.062
0.111
2.626
0.009
R R2 Adjusted R2
0.654* 0.428 0.422*
F
73.918
DF
(4, 395)
*p<0.001