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Predictive Validity in a Prospective Follow-up of PTSD in Preschool Children
Predictive Validity in a Prospective Follow-up of PTSD in Preschool Children MICHAEL S. SCHEERINGA, M.D., M.P.H., CHARLES H. ZEANAH, M.D., LEANN MYERS, PH.D., AND FRANK W. PUTNAM, M.D.
ABSTRACT Objective: To examine the predictive validity of an alternative to the DSM-IV for diagnosing posttraumatic stress disorder (PTSD) in preschool children and prospectively explore the course of PTSD symptomatology. Method: Sixty-two traumatized children, ages 20 months through 6 years, were assessed three times in 2 years with caregiver diagnostic interviews. Results: PTSD diagnosis at visit 1 significantly predicted degree of functional impairment 1 and 2 years later and predicted PTSD diagnosis 2 years later but not 1 year later. The lack of 1-year diagnostic continuity may be explained by children with new traumas. Unexpectedly, overall PTSD symptoms did not remit over time, regardless of community treatment; however, reexperiencing symptoms decreased and avoidance/numbing symptoms increased with time, with avoidance/numbing symptoms increasing at a faster rate in children with PTSD at visit 1. The previous finding that arousal may cause emotional numbing was not replicated. Significantly more children were functionally impaired at visits 2 (48.9%) and 3 (74.3%) than were diagnosed with PTSD (23.4% and 22.9%, respectively). Conclusions: This study demonstrates predictive validity for the alternative method of diagnosing PTSD in preschool children. The unremitting course of PTSD symptomatology in preschool children and rates of impairment that are higher than rates of diagnosis indicate the need for efficacious treatment. J. Am. Acad. Child Adolesc. Psychiatry, 2005;44(9):899–906.
Key Words: posttraumatic stress disorder, pre-
school, prospective, predictive validity.
Research on the course of posttraumatic stress disorder (PTSD) in preschool-age children represents a gap in our knowledge. Numerous studies in adults have shown that the course of PTSD is long-term, and one factor that increases this likelihood is childhood trauma (Breslau, 2001). Within this long-term course, there is a Accepted March 31, 2005. Drs. Scheeringa and Zeanah are with the Institute of Infant and Early Childhood Mental Health, Department of Psychiatry and Neurology, Tulane University School of Medicine; Dr. Myers is with the Department of Biostatistics, Tulane University School of Public Health and Tropical Medicine, New Orleans; and Dr. Putnam is with the Mayerson Center for Safe and Healthy Children, Children’s Hospital Medical Center, Cincinnati. This work was supported by NIMH grant (K08 MH01706). The authors thank the Medical Center of Louisiana Charity Hospital Trauma Center, nursing staff of the Surgical Intermediate Care Area, Crescent House, Metropolitan Battered Women’s Program, Tulane Hospital for Children Pediatric Hematology/Oncology Program, and Children’s Bureau of Greater New Orleans. Reprint requests to Dr. Michael S. Scheeringa, 1440 Canal Street, TB52, New Orleans, LA; e-mail: [email protected]. 0890-8567/05/4409–08992005 by the American Academy of Child and Adolescent Psychiatry. DOI: 10.1097/01.chi.0000169013.81536.71
gradual diminution of symptoms during 1 to 2 years in adults with PTSD (McFarlane and Yehuda, 1996). Because the early years of life are the time when the brain is developing the most rapidly, theories have been proposed that chronic fear responses during early childhood may create a more ominous course and permanently disturb the development of the central nervous system (Kaufman and Charney, 2001). In contrast, it is tempting to speculate that younger children are at less risk from the effects of trauma because they are protected by the support of their caregivers (Laor et al., 1997) and their limited abstraction capacities to be aware of dangers inherent in most traumas (Yule, 1994). This study, the first known longitudinal examination of PTSD in preschool-age children, examines these competing theories in a preliminary fashion by exploring the stability of the diagnosis over the course of 2 years and whether it predicts future functional impairment. Until recently, many believed that young children had only temporary reactions to life-threatening experiences, quickly putting the experiences behind them
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(Yule, 2001); however, as case studies and systematic research began to document, it became apparent that preschool-age children develop PTSD as clearly and severely as do other age groups. A series of systematic studies have demonstrated that the DSM-IV criteria for PTSD do not adequately take into account developmental issues for preschool children. In five studies by three teams of investigators, it has been shown that an alternative method of diagnosing PTSD is more valid in this age group (Ippen et al., 2004; Ohmi et al., 2002; Scheeringa et al., 1995, 2001, 2003). In two trauma cohort studies, none of the children met criteria for PTSD with DSM-IV criteria following serious trauma, but 25%–26% met the threshold for diagnosis using the alternative criteria. Because these children were highly symptomatic, with a mean of 6.1 PTSD symptoms (Ohmi et al., 2002; Scheeringa et al., 2003), the failure to meet the diagnostic threshold using DSM-IV criteria was particularly striking. Nevertheless, one of the remaining issues of diagnostic validity for young children is the predictive validity of competing diagnostic approaches. Predictive validity is the degree to which the diagnosis of a mental disorder predicts some important aspect, such as course, complications, and response to treatment (Spitzer and Williams, 1980). These aspects are important for the scientific purpose of establishing the validity of the diagnosis and for the clinical purposes of education and treatment. Laor et al. (1997) conducted the only other known longitudinal follow-up of traumatized preschool children. They followed 3- to 5-year-old children 30 months after Scud missile attacks in Israel. Their measures did not include a diagnosis of PTSD or a caregiver report of children’s PTSD symptoms, so their findings cannot speak to issues of diagnostic validity. They showed that stress symptoms decreased over time in the displaced group that had to move from their homes but that they did not in the undisplaced group, which may reflect the initially higher level of symptoms in the displaced group. Our longitudinal data also give us an opportunity to replicate the finding in older children (Weems et al., 2003) and adults (Flack et al., 2000; Litz et al., 1997) that chronic hyperarousal of PTSD predicts subsequent emotional numbing (EN). EN (consisting of loss of interest, detachment, and restricted affect) has been identified as distinct from the numbing symptoms in the avoidance/numbing criterion (criterion C) in factor analytic studies of PTSD in children and
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adolescents (Sack et al., 1997) and preschool children (Ippen et al., 2004). The demonstration of a lead–lag relationship between hyperarousal and EN would support a causal, mechanism-driven theory that chronic hyperarousal leads to the depletion of biological, cognitive, and emotional resources that characterize EN. Thus, the second aim of this study was to determine whether early signs and symptoms of hyperarousal in young children are associated with subsequent EN. Our three hypotheses are as follows: (1) children who were diagnosed with PTSD at the 1- and 2-year followup visits will be more likely to have been diagnosed with PTSD at visit 1; (2) children diagnosed with PTSD at visit 1 will show functional impairment in more domains at the 1- and 2-year follow-ups as compared with those not diagnosed at visit 1; and (3) children who have prominent hyperarousal symptoms after a trauma will be more likely to show EN 1 and 2 years later. An additional exploratory goal is to examine how the degree of functional impairment interrelates with the diagnosis and severity of PTSD. METHOD Participants Sixty-two traumatized children who were ages 20 months through 6 years were recruited (see Scheeringa et al., 2003 for details) from an inpatient unit of a level I trauma center (n = 21), three battered women’s shelters (n = 19), an outpatient mental health clinic (n = 9), a cancer center (n = 6), and by word of mouth (n = 7). The trauma center participants experienced automobile collisions and other acute accidental injuries. The battered women’s shelter participants witnessed domestic violence against their mothers. The cancer patients experienced highly invasive and repeated medical procedures while awake (spinal tap and bone marrow aspirations). Our inclusion criteria required that the children show at least one symptom of PTSD more than 2 months after the event. At least one symptom was required because we sought to make sure that we were not too liberal in the types of traumas that were included. Exclusion criteria included (1) disabling preexisting medical disorders, (2) severe developmental disorders, and (3) for the trauma service victims, a Glasgow Coma Scale score of £6 in the emergency department (a score <6 often prevents having a substantial memory of the event and produces cognitive deficits that would make them different from the other injured children). No potential subjects met the exclusion criteria. Three families refused to participate when they were approached. Measures Posttraumatic Stress Disorder Semi-structured Interview and Observational Record for Infants and Young Children (Scheeringa and Zeanah, 1994). This parent interview was used for visit 1 only. This
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measure contains all of the DSM-IV PTSD items plus alternative wording for five of the items (recollections, flashbacks, diminished interests, detachment, and irritability) to make them more developmentally sensitive for this age group, based on a series of diagnostic validity studies (Scheeringa et al., 1995, 2001, 2003). A diagnosis can be made either by the DSM-IV algorithm or by the empirically validated alternative algorithm for young children. The alternative algorithm does not require criterion A(2) (the child’s reaction at the time of the event) and requires only one item to meet the avoidance/numbing criterion as opposed to the DSM-IV requirement for three items. Symptoms must have been present for at least 1 month. A random sample of 18% of the interviews (n = 11) were double coded from videotape for interrater reliability. Cohen’s k for all 18 PTSD items was 0.75. Cohen’s k for scoring enough items to meet the alternative diagnostic threshold was 0.79. NIMH Diagnostic Interview Schedule for Children, Version IV (DISC). For visits 2 and 3, we used the DISC PTSD module instead of the Posttraumatic Stress Disorder Semi-structured Interview because the DISC contained separate sections for functional impairment. Each disorder module contains a separate section to assess symptom-related functional impairment in five domains (see below). The impairment criterion for each disorder may also be met by an item rating the child’s symptom-related emotional distress, consistent with the DSM-IV. The DISC has shown moderate to excellent test-retest reliability for specific disorders, including 0.54 for oppositional defiant disorder, 0.58 for separation anxiety disorder, 0.66 for major depressive disorder, and 0.79 for attention-deficit/hyperactivity disorder in a clinical sample but slightly lower values in a community sample (Shaffer et al., 2000). Accommodations were made in this study to measure the five PTSD items with different wording from the alternative method. Raters were trained to (1) record recollections with and without distress, (2) record flashbacks based on behavioral observations without verbal confirmation from a child about the nature of the flashback, and (3) record irritability if manifest as the new onset of extreme temper tantrums. A separate sheet of questions was added at the end to rate (4) the alternative wording for the diminished interests (constriction of play) and (5) detachment items (social withdrawal). This allowed, for example, diminished interests to be recorded by the DSM-IV wording by the original DISC question or by the alternative method wording with the added question. The module starts with an inventory of traumatic life events that was used to systematically track the occurrence of new events between visits. Emotional Numbing. EN is a subset of the seven possible items in the avoidance/numbing criterion of PTSD. We calculated an EN score as the sum of the three items (diminished interest, detachment, and restricted range of affect) from the diagnostic interviews that were used at each visit. The range was 0 to 3, identical to one of the measures used by Litz et al. (1997). Hyperarousal. We calculated hyperarousal as the sum of the five criterion D items (difficulty sleeping, irritability and anger, difficulty concentrating, hypervigilance, and exaggerated startle) from the diagnostic interview that was used at each visit. The range was 0 to 5, similar to the measure used by Litz et al. (1997). Functional Impairment. This included the five domains of impairment in the DISC: annoyed parent, prevented activities with family, prevented activities with peers, interfered with school work, and annoyed teacher. A continuous score was created by summing these items. A categorical score was derived by recording it if any of the five domains were recorded. Child distress was not included in the primary analyses to provide the purest measure of functional impairment.
Treatment. Treatment was defined as the child’s receiving one or more treatment sessions from a community provider. Twelve participants received treatment for their PTSD symptoms in the community before visit 1. Four of these plus five additional participants received community treatment between visits 1 and 2. Three of these continued to receive community treatment between visits 2 and 3. A total of 17 different participants received treatment at some time. The number of treatment sessions for each participant was not recorded. One child was placed on a stimulant medication after visit 1, and one child was placed on a selective serotonin reuptake inhibitor plus an a-adrenergic agonist after visit 2. Procedure The Tulane University Committee on the Use of Human Subjects approved this study. When participants arrived at the laboratory, the study was verbally explained to the caregivers, and they were given a consent form to read. Written informed consent was obtained. Voluntary assent was obtained from children. A variety of measures were obtained at the visit. Data are reported only on the measures listed above. From the index trauma to visit 1, the mean length of time was 11.2 months (SD = 11.0), the median was 7.5 months, and the range was 2–52 months. We attempted to reassess participants at 12-month intervals thereafter. The mean length of time between visits 1 and 2 was 13.7 months (SD = 2.9), the median was 14 months, and the range was 7–19 months. The mean length of time between visits 2 and 3 was 13.1 months (SD = 2.7), the median was 12 months, and the range was 9–20 months. Data Analysis Fisher exact test was used to test whether children who were diagnosed with PTSD at the follow-up visits had greater proportions that had been diagnosed with PTSD at visit 1. Linear regression tests were used to test whether a diagnosis of PTSD at visit 1 predicted functional impairment in the follow-up assessments. A mixed-models analysis was used to examine the longitudinal course of the number of PTSD symptoms over all three visits. This method allowed for the use of data from all participants because some had missing data at visits 2 and 3. A compound symmetry covariance structure was used. Where multiple tests were conducted, corrections for the a level of significance were not used because these analyses were exploratory. Spearman correlations were used to examine the bivariate relationships between hyperarousal and EN. The binomial distribution was used to calculate the probability that the rates of impairment were different from the rates of PTSD diagnosis.
RESULTS Predictive Validity of Visit 1 PTSD Diagnosis for 1- and 2-Year PTSD Diagnoses
Neither the presence of the PTSD diagnosis nor the number of PTSD symptoms at visit 1 was significantly related to child age, type of trauma, gender, race, maternal age, maternal employment, or the number of parents in the home. The rates of diagnosis of PTSD at each
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visit were 25.8% at visit 1 (16 diagnosed of 62), 23.4% at visit 2 (11 of 47), and 22.9% at visit 3 (8 of 35) (Table 1). Overall, 38.7% (n = 24) were diagnosed with PTSD at some point during the 2 years of this study. The tracking of subjects and diagnoses (and no diagnoses) at each visit is shown in Figure 1. Of the 16 children who were diagnosed at visit 1, the portion that was retained at visit 2 had a 30.8% rate of rediagnosis with PTSD, and the portion that was retained at visit 3 had a 50% rate of rediagnosis. Of the 46 children who were not diagnosed at visit 1, the portion that was retained at visit 2 had a 79.4% rate of not being diagnosed again, and the portion that was retained at visit 3 had a 91.3% rate of not being diagnosed again. The children who were diagnosed with PTSD at visit 2 did not have a significantly higher proportion of diagnoses of PTSD at visit 1 compared with the children who were not diagnosed with PTSD at visit 2 (Fisher exact test, p = .47, two sided). The children who were diagnosed with PTSD at visit 3, however, had a significantly higher proportion of diagnoses of PTSD at visit 1 as compared with the children who were not diagnosed with PTSD at visit 3 (Fisher exact test, p < .05, two sided). These findings suggest that there was greater stability of diagnostic status between visits 1 and 3 than between visits 1 and 2. Thus, visits 1 to 3 stability partially supports the predictive validity of the alternative method of diagnosing PTSD in preschool children. The lack of statistically significant stability between visits 1 and 2 seemed to be largely the result of seven participants who were not diagnosed at visit 1 with PTSD but were newly diagnosed at visit 2. Compared with the rest of the visit 2 sample, these seven children were significantly younger at visit 2 (52.7 versus 72.1 months, t = 2.96, df = 45, p < .01) and had a shorter length of time between their trauma and their visit 2 (19.9 versus 24.5
months, t = 2.55 for unequal variances, df = 26.5, p < .05). Six of the seven were boys, but this difference did not reach statistical significance (Fisher exact test, p = .10, two sided). Most important, five of the seven experienced new stressors between visits 1 and 2, including one who endured the suicide of a stepfather, one who endured the death of a close uncle, and three who witnessed new domestic violence. A sixth subject had extensive facial scarring from his original trauma and was being evaluated by plastic surgeons. In contrast, of the 40 other participants at visit 2 who were not newly diagnosed, only two endured new stressors in the interim. None of the participants diagnosed at visit 1 experienced new traumas between visits 1 and 2. Only one child (who had PTSD at all three visits) experienced a new major stressor between visits 2 and 3. Predictive Validity of Visit 1 PTSD Diagnosis for 1- and 2-Year Functional Impairment
The visit 1 PTSD group was impaired in significantly more domains 1 year later at visit 2 (2.2 of 5 possible) as compared with the visit 1 No-PTSD group (0.5) in a simple linear regression test (F = 23.21, df = 1, 45, p < .0001, R2 = 0.34). When child emotional distress was allowed as a sixth possible domain of impairment, the significant relationship was not changed, but the amount of variance accounted for actually decreased (R2 = 0.21). The visit 1 PTSD group was also impaired in significantly more domains 2 years later at visit 3 (3.1 of 5 possible) as compared with the visit 1 No-PTSD group (1.7; F = 6.82, df = 1, 33, p < .05, R2 = 0.17). When child emotional distress was allowed as a sixth possible domain of impairment, the significant relationship was not changed, and the amount of variance accounted for slightly decreased (R2 = 0.15).
TABLE 1 Rates of PTSD Diagnosis and Criteria B, C, and D at All Three Visits Visit 1 (n = 62) Visit 2 (n = 47) DSM-IV PTSD diagnosis Alternative PTSD diagnosis Reexperiencing Avoidance/numbinga Hyperarousal
0% 25.8% 67.7% 38.7% 45.2%
(n (n (n (n
= = = =
16) 42) 24) 28)
2.1% 23.4% 48.9% 44.7% 34.0%
(n (n (n (n (n
= = = = =
1) 11) 23) 21) 16)
Visit 3 (n = 35) 11.4% 22.9% 37.1% 42.9% 51.4%
(n (n (n (n (n
= = = = =
4) 8) 13) 15) 18)
Note: PTSD = posttraumatic stress disorder. The threshold for avoidance/numbing is the alternative method threshold of one symptom.
a
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Fig. 1 Retention of participants and PTSD/No-PTSD status at the three visits. PTSD = posttraumatic stress disorder.
Course of Total PTSD Symptomatology
We examined the course of total PTSD symptomatology at each visit in a mixed-models analysis. We incorporated into this analysis a test for the effect of time from trauma to visit 1 because there was a wide range and a test for the effect of treatment because 17 subjects received community treatment. The first model included PTSD diagnosis at visit 1 as the group variable (PTSD versus No-PTSD at visit 1), time between visits (the time variable) as a continuous variable (in months), and a group 3 time interaction term. The PTSD group had significantly higher levels of PTSD symptoms than did the No-PTSD group (F = 15.89, df = 1, 60, p < .001). There was no change in symptoms over time (F = 2.61, df = 1, 80, p = .11) and no significant interaction of group with time (F = 0.0, df = 1, 80, p = .97). A second model was tested with length of time from the trauma to the first assessment added as a predictor variable to determine whether this was a potential confounder. Time from the trauma was not significant, and the significance of the findings in the first model equation was not substantially changed. A third model was tested with community treatment added as a predictor variable to determine whether this was a potential confounder. Community treatment was not significant, and, again, the significance of the findings in the first model equation was not substantially altered. Thus, we concluded that the visit 1 PTSD group continued to have significantly more symptoms than the No-PTSD group over 2 years, there was no significant decrease in symptoms over 2 years, and there were no effects for time from trauma to assessment or for community treatment. A final model was created by dropping the group with time interaction term from the first model because it was nonsignificant, and the parameter estimates from this model equation were then used to create a graph to visualize the course of the number of PTSD symp-
toms corrected for the time from trauma. Three time points were chosen to approximate the three visits in our study: 4 months posttrauma approximated visit 1, 16 months posttrauma approximated visit 2, and 28 months posttrauma approximated visit 3 (Fig. 2). It is apparent that, at 4 months posttrauma, the group that was diagnosed with PTSD at visit 1 had an estimated mean of 6.1 PTSD symptoms and the nondiagnosed group had a mean of 2.7 PTSD symptoms. This number of symptoms did not diminish by even as much as one symptom over 2 years for either group. A power analysis indicated that to detect a decrease of one symptom for group means between two visits, at a significance level of 0.05 and a desired power of 0.80, a sample size of 78 is needed. To detect a decrease of two symptoms between visits, however, a sample size of 20 is needed. Thus, this study had sufficient power to detect a two-symptom or more change but not a one-symptom change.
Fig. 2 Number of PTSD symptoms over time from a mixed-models analysis equation adjusted for time from trauma. Visit 1 in this study is approximated by 4 months posttrauma, visit 2 by 16 months posttrauma, and visit 3 by 28 months posttrauma.
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Course of PTSD Criteria B, C, and D
The courses of each PTSD symptom criterion were also examined with mixed-models analyses to test for changes over time and between groups. The presence of reexperiencing symptoms (criterion B) decreased substantially over time, from being present in 67.7% of the sample at visit 1 to 37.1% at visit 3 (Table 1). A mixed-models analysis showed that the visit 1 PTSD group had significantly more reexperiencing symptoms than the visit 1 No-PTSD group (F = 8.23, df = 1,60, p < .01). The number of reexperiencing symptoms significantly decreased with time (F = 23.11, df = 1, 80, p < .0001; Fig. 3). There was no significant interaction of PTSD status with time (F = 0.13, df = 1,80, p = .72). There was no effect of time from trauma when this was added in a separate model. There was neither an effect of community treatment nor an effect of a community treatment with time interaction. The visit 1 PTSD group had significantly more symptoms of avoidance/numbing (criterion C) than the visit 1 No-PTSD group (F = 4.02, df = 1, 60, p < .05). The number of avoidance/numbing symptoms significantly increased with time (F = 9.24, df = 1, 80, p < .01), but there was a significant interaction of visit 1 PTSD status with time (F = 4.85, df =1, 80, p < .05). The visit 1 PTSD group increased their number of avoidance/numbing symptoms at a greater rate than did the visit 1 No-PTSD group (Fig. 3). There were no effects of time from trauma, community treatment, or com-
munity treatment with time interaction when these were added in separate models. The visit 1 PTSD group had significantly more hyperarousal symptoms (criterion D) than did the visit 1 NoPTSD group (F = 12.23, df = 1, 60, p < .001). There was no significant change in hyperarousal symptoms over time (F = 3.28, df = 1, 80, p = .074), and there was no significant interaction of visit 1 PTSD status with time (F = 1.44, df = 1, 80, p = 23; Fig. 3). There were no effects of time from trauma, community treatment, or community treatment with time interaction when these were added in separate models. Overall, the earlier finding of no significant change in PTSD symptoms over time appears more complicated when examined by criteria B, C, and D. The significant decrease in reexperiencing is ‘‘balanced’’ by the significant increase in avoidance/numbing, and the rate of increase in avoidance/numbing over time is greater for the visit 1 PTSD group as compared with the visit 1 NoPTSD group. We attempted to replicate in older populations the finding that chronic arousal symptoms (criterion D) may cause EN symptoms. The fist step was to examine the correlations between hyperarousal at all three visits and the EN variables at all three visits. The correlations between visit 1 hyperarousal and visit 1 EN (r = 0.06) and visit 2 EN (r = 0.14) and visit 3 EN (r = 0.31) were neither large nor significant. Visit 2 hyperarousal correlated significantly with visit 2 EN (r = 0.36, p < .05) but not with visit 3 EN (r = 0.23). Visit 3 hyperarousal did not correlate significantly with visit 3 EN (0.29). These largely nonsignificant relationships precluded any further analysis and did not support the theory that chronic arousal symptoms cause numbing symptoms in this population. Impaired but Not Diagnosed
Fig. 3 Longitudinal courses of criteria B, C, and D symptoms in the groups that were diagnosed (visit 1 PTSD) and not diagnosed (visit 1 No-PTSD) with PTSD at visit 1.
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At visit 2, according to parent ratings, significantly more children were impaired in at least one domain (48.9%) than had the full diagnosis of PTSD (23.4%; binomial test, p < .0001). At visit 3, this discrepancy between rates of impairment (74.3%) and PTSD diagnosis (22.9%) was even more pronounced (binomial test, p < .0001; Fig. 4). The significance of these findings did not change if child distress was allowed as a sixth domain of functional impairment. The most common domain of impairment at visit 2 was child distress (34%), followed by annoyed parents
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Fig. 4 Percentages of children with PTSD and impairment in 1, 2, 3, 4, or 5 domains at visits 2 and 3.
(32%), restricted participation in activities with the family (26%), restricted participation with peers (19%), annoyed teachers (17%), and school work (6%). The most common domain of impairment at visit 3 was parent annoyed (66%), restricted activities with the family (51%), child distress (40%), restricted participation with peers (37%), school work (31%), and teacher annoyed (29%). DISCUSSION
This first longitudinal study of PTSD diagnosis and symptomatology in preschool children makes several contributions. First, these findings support the predictive validity of the alternative method for diagnosing PTSD in infant and preschool children. Children diagnosed with PTSD at visit 1 predicted significantly more symptoms of PTSD and functional impairment in more domains over the course of 2 years than did the No-PTSD group. Second, the longitudinal analysis of the number of PTSD symptoms demonstrated that symptoms did not remit over 2 years, even with community treatment. This finding was unexpected. The majority of previous studies, albeit in older populations, found that PTSD rates and symptoms decrease with time but do not completely disappear (Breslau, 2001), although there have been exceptions, such as severe burns in adults (Madianos et al., 2001) and children terrified by brush fire (McFarlane, 1987). This suggests the disturbing possibility that young children who are vulnerable to developing PTSD after traumas are doubly vulnerable to a more unremitting course of illness. This raises questions about neurobiological vulnerability to traumatic experiences in young children with rapidly developing brains.
Third, as has been shown repeatedly in adult studies, the reexperiencing (criterion B) symptoms were more prominent initially and then faded relatively more with time (Blank, 1993). In contrast to previous studies, avoidance/numbing (criterion C) symptoms increased over time, particularly for the visit 1 PTSD group. Despite this increase in avoidance/numbing symptoms over time, we were not able to replicate the previous finding that chronic expression of hyperarousal seemed to drive the development of EN (a subset of avoidance/numbing; Flack et al., 2000; Litz et al., 1997; Weems et al., 2003). Fourth, substantially more children were considered functionally impaired by their caregivers than were diagnosed with PTSD. The rates of impairment were two to three times the rates of diagnosis, and the discrepancy appeared to grow between visits 2 and 3. This finding is consistent with the finding by Angold et al. (1999) in their large epidemiological study of 9- to 13-year-old children that 8.9% of non–mental health services users and 21.3% of service users were impaired but not diagnosed with any type of disorder. They suggested that these children would qualify for not otherwise specified (NOS) categories but that greater attention was needed to operationalize the NOS categories. Similarly, we hope that our finding stimulates attention on how to best operationalize the designations of children who are impaired and need treatment. Limitations
Assessment of avoidance/numbing symptoms may not be generalizable to older populations because of either the inherent developmental barriers that seem to prevent young children from developing all of these items (Scheeringa et al., 2003) or the absence of self-report for these relatively more abstract and internalized items or both. This was not a help-seeking cohort, so the results may not be generalizable to clinic populations. The types of traumatic events were heterogeneous in this sample and may not be generalizable to more homogeneous cohorts. Clinical Implications
PTSD symptomatology and associated functional impairment do not remit spontaneously in this young population. Contrary to examples of plasticity and resiliency in abnormal development, such as recovery from hemispherectomies to treat intractable epilepsy
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(Peacock, 1995) and popular notions that young children are more resilient, the data for PTSD in early childhood after serious trauma suggest otherwise. This ought to focus attention in the field on developing effective and accessible treatment for traumatized young children. These data highlight the need to treat the avoidance and numbing symptomatology in particular and to provide treatment as early as possible in children’s lives. Given the acknowledged importance of caregiving relationships for young children, for children who experience abuse and neglect from their caregivers, intervention plans also ought to consider placing children with supportive caregivers. No effective treatment for preschool children who experienced all types of traumatic events has yet been studied for efficacy. There is a substantial case study literature on the treatment of PTSD in preschool children (Gaensbauer and Siegel, 1995), and the efficacy of manual-based cognitivebehavioral treatment protocols for sexual abuse trauma has been demonstrated (Cohen and Mannarino, 1996), but an evidence-based protocol for all types of traumatic events is clearly needed. Given the finding in this study that two to three times as many children are functionally impaired from PTSD-related symptoms as are diagnosed, treatment ought not be restricted to only those who meet the diagnostic threshold. This ought to inspire thoughtful considerations for primary care providers who make referrals, frontline mental health clinicians who conduct triage and intake, and health insurance that sets restrictions on diagnosis-driven access to care. Disclosure: The authors have no financial relationships to disclose. REFERENCES Angold A, Costello E, Farmer E (1999), Impaired but undiagnosed. J Am Acad Child Adolesc Psychiatry 38:129–137 Blank A (1993), The longitudinal course of posttraumatic stress disorder. In: Posttraumatic Stress Disorder: DSM-IV and Beyond, Davidson J, Foa E, eds. Washington, DC: American Psychiatric Press, pp 3–22 Breslau N (2001), Outcomes of posttraumatic stress disorder. J Clin Psychiatry 62:55–59 Cohen J, Mannarino A (1996), A treatment outcome study for sexually abused preschool children: initial findings. J Am Acad Child Adolesc Psychiatry 35:42–50
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Flack W, Litz B, Hsieh F, Kaloupek D, Keane T (2000), Predictors of emotional numbing, revisited: a replication and extension. J Trauma Stress 13:611–618 Gaensbauer T, Siegel C (1995), Therapeutic approaches to posttraumatic stress disorder in infants and toddlers. Infant Ment Health J 16:292–305 Ippen C, Briscoe-Smith A, Lieberman A (2004), PTSD symptomatology in young children. Presented at the International Society for Traumatic Stress Studies 20th Annual Meeting, New Orleans, November 14–18 Kaufman J, Charney D (2001), Effects of early stress on brain structure and function: implications for understanding the relationship between child maltreatment and depression. Dev Psychopathol 13:451–471 Laor N, Wolmer L, Mayes L, Gershon A (1997), Israeli preschool children under Scuds: a 30-month follow-up. J Am Acad Child Adolesc Psychiatry 36:349–356 Litz B, Schlenger W, Weathers F, Caddell J, Fairbank J, LaVange L (1997), Predictors of emotional numbing in posttraumatic stress disorder. J Trauma Stress 10:607–617 Madianos M, Papaghelis M, Ioannovich J, Dafni R (2001), Psychiatric disorders in burn patients: a follow-up study. Psychother Psychosom 70:30–37 McFarlane A (1987), Posttraumatic phenomena in a longitudinal study of children following a natural disaster. J Am Acad Child Adolesc Psychiatry 26:764–769 McFarlane A, Yehuda R (1996), Resilience, vulnerability, and the course of posttraumatic reactions. In: Traumatic Stress: The Effects of Overwhelming Experience on Mind, Body, and Society, van der Kolk B, McFarlane A, Weisaeth L, eds. New York: Guilford Press, pp 155–181 Ohmi H, Kojima S, Awai Y et al. (2002), Post-traumatic stress disorder in pre-school aged children after a gas explosion. Eur J Pediatr 161:643–648 Peacock W (1995), Hemispherectomy for the treatment of intractable seizures in childhood. Neurosurg Clin N Am 6:549–563 Sack W, Seeley J, Clarke G (1997), Does PTSD transcend cultural barriers? A study from the Khmer Adolescent Refugee Project. J Am Acad Child Adolesc Psychiatry 36:49–54 Scheeringa M, Peebles C, Cook C, Zeanah C (2001), Toward establishing procedural, criterion, and discriminant validity for PTSD in early childhood. J Am Acad Child Adolesc Psychiatry 40:52–60 Scheeringa M, Zeanah C (1994), Posttraumatic Stress Disorder Semi-Structured Interview and Observational Record for Infants and Young Children. New Orleans: Tulane University Scheeringa M, Zeanah C, Drell M, Larrieu J (1995), Two approaches to the diagnosis of posttraumatic stress disorder in infancy and early childhood. J Am Acad Child Adolesc Psychiatry 34:191–200 Scheeringa M, Zeanah C, Myers L, Putnam F (2003), New findings on alternative criteria for PTSD in preschool children. J Am Acad Child Adolesc Psychiatry 42:561–570 Shaffer D, Fisher P, Lucas C (2000), NIMH Diagnostic Interview Schedule for Children Version IV (NIMH DISC-IV): description, differences from previous versions, and reliability of some common diagnoses. J Am Acad Child Adolesc Psychiatry 39:28–38 Spitzer R, Williams J (1980), Classification of mental disorders and DSMIII. In: Comprehensive Textbook of Psychiatry, Vol 4, Kaplan H, Freedman A, Sadock B, eds. Baltimore: Williams & Wilkins, pp 1035–1072 Weems C, Saltzman K, Reiss A (2003), A prospective test of the association between hyperarousal and emotional numbing in youth with a history of traumatic stress. J Clin Child Adolesc Psychol 32:166–171 Yule W (1994), Posttraumatic stress disorders. In: Child and Adolescent Psychiatry: Modern Approaches, 3rd ed., Rutter M, Taylor E, Hersov L, eds. Oxford: Blackwell Science, pp 392–406 Yule W (2001), Posttraumatic stress disorder in the general population and in children. J Clin Psychiatry 62:23–28
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ABSTRACT Objective: To examine the predictive validity of an alternative to the DSM-IV for diagnosing posttraumatic stress disorder (PTSD) in preschool children and prospectively explore the course of PTSD symptomatology. Method: Sixty-two traumatized children, ages 20 months through 6 years, were assessed three times in 2 years with caregiver diagnostic interviews. Results: PTSD diagnosis at visit 1 significantly predicted degree of functional impairment 1 and 2 years later and predicted PTSD diagnosis 2 years later but not 1 year later. The lack of 1-year diagnostic continuity may be explained by children with new traumas. Unexpectedly, overall PTSD symptoms did not remit over time, regardless of community treatment; however, reexperiencing symptoms decreased and avoidance/numbing symptoms increased with time, with avoidance/numbing symptoms increasing at a faster rate in children with PTSD at visit 1. The previous finding that arousal may cause emotional numbing was not replicated. Significantly more children were functionally impaired at visits 2 (48.9%) and 3 (74.3%) than were diagnosed with PTSD (23.4% and 22.9%, respectively). Conclusions: This study demonstrates predictive validity for the alternative method of diagnosing PTSD in preschool children. The unremitting course of PTSD symptomatology in preschool children and rates of impairment that are higher than rates of diagnosis indicate the need for efficacious treatment. J. Am. Acad. Child Adolesc. Psychiatry, 2005;44(9):899–906.
Key Words: posttraumatic stress disorder, pre-
school, prospective, predictive validity.
Research on the course of posttraumatic stress disorder (PTSD) in preschool-age children represents a gap in our knowledge. Numerous studies in adults have shown that the course of PTSD is long-term, and one factor that increases this likelihood is childhood trauma (Breslau, 2001). Within this long-term course, there is a Accepted March 31, 2005. Drs. Scheeringa and Zeanah are with the Institute of Infant and Early Childhood Mental Health, Department of Psychiatry and Neurology, Tulane University School of Medicine; Dr. Myers is with the Department of Biostatistics, Tulane University School of Public Health and Tropical Medicine, New Orleans; and Dr. Putnam is with the Mayerson Center for Safe and Healthy Children, Children’s Hospital Medical Center, Cincinnati. This work was supported by NIMH grant (K08 MH01706). The authors thank the Medical Center of Louisiana Charity Hospital Trauma Center, nursing staff of the Surgical Intermediate Care Area, Crescent House, Metropolitan Battered Women’s Program, Tulane Hospital for Children Pediatric Hematology/Oncology Program, and Children’s Bureau of Greater New Orleans. Reprint requests to Dr. Michael S. Scheeringa, 1440 Canal Street, TB52, New Orleans, LA; e-mail: [email protected]. 0890-8567/05/4409–08992005 by the American Academy of Child and Adolescent Psychiatry. DOI: 10.1097/01.chi.0000169013.81536.71
gradual diminution of symptoms during 1 to 2 years in adults with PTSD (McFarlane and Yehuda, 1996). Because the early years of life are the time when the brain is developing the most rapidly, theories have been proposed that chronic fear responses during early childhood may create a more ominous course and permanently disturb the development of the central nervous system (Kaufman and Charney, 2001). In contrast, it is tempting to speculate that younger children are at less risk from the effects of trauma because they are protected by the support of their caregivers (Laor et al., 1997) and their limited abstraction capacities to be aware of dangers inherent in most traumas (Yule, 1994). This study, the first known longitudinal examination of PTSD in preschool-age children, examines these competing theories in a preliminary fashion by exploring the stability of the diagnosis over the course of 2 years and whether it predicts future functional impairment. Until recently, many believed that young children had only temporary reactions to life-threatening experiences, quickly putting the experiences behind them
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(Yule, 2001); however, as case studies and systematic research began to document, it became apparent that preschool-age children develop PTSD as clearly and severely as do other age groups. A series of systematic studies have demonstrated that the DSM-IV criteria for PTSD do not adequately take into account developmental issues for preschool children. In five studies by three teams of investigators, it has been shown that an alternative method of diagnosing PTSD is more valid in this age group (Ippen et al., 2004; Ohmi et al., 2002; Scheeringa et al., 1995, 2001, 2003). In two trauma cohort studies, none of the children met criteria for PTSD with DSM-IV criteria following serious trauma, but 25%–26% met the threshold for diagnosis using the alternative criteria. Because these children were highly symptomatic, with a mean of 6.1 PTSD symptoms (Ohmi et al., 2002; Scheeringa et al., 2003), the failure to meet the diagnostic threshold using DSM-IV criteria was particularly striking. Nevertheless, one of the remaining issues of diagnostic validity for young children is the predictive validity of competing diagnostic approaches. Predictive validity is the degree to which the diagnosis of a mental disorder predicts some important aspect, such as course, complications, and response to treatment (Spitzer and Williams, 1980). These aspects are important for the scientific purpose of establishing the validity of the diagnosis and for the clinical purposes of education and treatment. Laor et al. (1997) conducted the only other known longitudinal follow-up of traumatized preschool children. They followed 3- to 5-year-old children 30 months after Scud missile attacks in Israel. Their measures did not include a diagnosis of PTSD or a caregiver report of children’s PTSD symptoms, so their findings cannot speak to issues of diagnostic validity. They showed that stress symptoms decreased over time in the displaced group that had to move from their homes but that they did not in the undisplaced group, which may reflect the initially higher level of symptoms in the displaced group. Our longitudinal data also give us an opportunity to replicate the finding in older children (Weems et al., 2003) and adults (Flack et al., 2000; Litz et al., 1997) that chronic hyperarousal of PTSD predicts subsequent emotional numbing (EN). EN (consisting of loss of interest, detachment, and restricted affect) has been identified as distinct from the numbing symptoms in the avoidance/numbing criterion (criterion C) in factor analytic studies of PTSD in children and
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adolescents (Sack et al., 1997) and preschool children (Ippen et al., 2004). The demonstration of a lead–lag relationship between hyperarousal and EN would support a causal, mechanism-driven theory that chronic hyperarousal leads to the depletion of biological, cognitive, and emotional resources that characterize EN. Thus, the second aim of this study was to determine whether early signs and symptoms of hyperarousal in young children are associated with subsequent EN. Our three hypotheses are as follows: (1) children who were diagnosed with PTSD at the 1- and 2-year followup visits will be more likely to have been diagnosed with PTSD at visit 1; (2) children diagnosed with PTSD at visit 1 will show functional impairment in more domains at the 1- and 2-year follow-ups as compared with those not diagnosed at visit 1; and (3) children who have prominent hyperarousal symptoms after a trauma will be more likely to show EN 1 and 2 years later. An additional exploratory goal is to examine how the degree of functional impairment interrelates with the diagnosis and severity of PTSD. METHOD Participants Sixty-two traumatized children who were ages 20 months through 6 years were recruited (see Scheeringa et al., 2003 for details) from an inpatient unit of a level I trauma center (n = 21), three battered women’s shelters (n = 19), an outpatient mental health clinic (n = 9), a cancer center (n = 6), and by word of mouth (n = 7). The trauma center participants experienced automobile collisions and other acute accidental injuries. The battered women’s shelter participants witnessed domestic violence against their mothers. The cancer patients experienced highly invasive and repeated medical procedures while awake (spinal tap and bone marrow aspirations). Our inclusion criteria required that the children show at least one symptom of PTSD more than 2 months after the event. At least one symptom was required because we sought to make sure that we were not too liberal in the types of traumas that were included. Exclusion criteria included (1) disabling preexisting medical disorders, (2) severe developmental disorders, and (3) for the trauma service victims, a Glasgow Coma Scale score of £6 in the emergency department (a score <6 often prevents having a substantial memory of the event and produces cognitive deficits that would make them different from the other injured children). No potential subjects met the exclusion criteria. Three families refused to participate when they were approached. Measures Posttraumatic Stress Disorder Semi-structured Interview and Observational Record for Infants and Young Children (Scheeringa and Zeanah, 1994). This parent interview was used for visit 1 only. This
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measure contains all of the DSM-IV PTSD items plus alternative wording for five of the items (recollections, flashbacks, diminished interests, detachment, and irritability) to make them more developmentally sensitive for this age group, based on a series of diagnostic validity studies (Scheeringa et al., 1995, 2001, 2003). A diagnosis can be made either by the DSM-IV algorithm or by the empirically validated alternative algorithm for young children. The alternative algorithm does not require criterion A(2) (the child’s reaction at the time of the event) and requires only one item to meet the avoidance/numbing criterion as opposed to the DSM-IV requirement for three items. Symptoms must have been present for at least 1 month. A random sample of 18% of the interviews (n = 11) were double coded from videotape for interrater reliability. Cohen’s k for all 18 PTSD items was 0.75. Cohen’s k for scoring enough items to meet the alternative diagnostic threshold was 0.79. NIMH Diagnostic Interview Schedule for Children, Version IV (DISC). For visits 2 and 3, we used the DISC PTSD module instead of the Posttraumatic Stress Disorder Semi-structured Interview because the DISC contained separate sections for functional impairment. Each disorder module contains a separate section to assess symptom-related functional impairment in five domains (see below). The impairment criterion for each disorder may also be met by an item rating the child’s symptom-related emotional distress, consistent with the DSM-IV. The DISC has shown moderate to excellent test-retest reliability for specific disorders, including 0.54 for oppositional defiant disorder, 0.58 for separation anxiety disorder, 0.66 for major depressive disorder, and 0.79 for attention-deficit/hyperactivity disorder in a clinical sample but slightly lower values in a community sample (Shaffer et al., 2000). Accommodations were made in this study to measure the five PTSD items with different wording from the alternative method. Raters were trained to (1) record recollections with and without distress, (2) record flashbacks based on behavioral observations without verbal confirmation from a child about the nature of the flashback, and (3) record irritability if manifest as the new onset of extreme temper tantrums. A separate sheet of questions was added at the end to rate (4) the alternative wording for the diminished interests (constriction of play) and (5) detachment items (social withdrawal). This allowed, for example, diminished interests to be recorded by the DSM-IV wording by the original DISC question or by the alternative method wording with the added question. The module starts with an inventory of traumatic life events that was used to systematically track the occurrence of new events between visits. Emotional Numbing. EN is a subset of the seven possible items in the avoidance/numbing criterion of PTSD. We calculated an EN score as the sum of the three items (diminished interest, detachment, and restricted range of affect) from the diagnostic interviews that were used at each visit. The range was 0 to 3, identical to one of the measures used by Litz et al. (1997). Hyperarousal. We calculated hyperarousal as the sum of the five criterion D items (difficulty sleeping, irritability and anger, difficulty concentrating, hypervigilance, and exaggerated startle) from the diagnostic interview that was used at each visit. The range was 0 to 5, similar to the measure used by Litz et al. (1997). Functional Impairment. This included the five domains of impairment in the DISC: annoyed parent, prevented activities with family, prevented activities with peers, interfered with school work, and annoyed teacher. A continuous score was created by summing these items. A categorical score was derived by recording it if any of the five domains were recorded. Child distress was not included in the primary analyses to provide the purest measure of functional impairment.
Treatment. Treatment was defined as the child’s receiving one or more treatment sessions from a community provider. Twelve participants received treatment for their PTSD symptoms in the community before visit 1. Four of these plus five additional participants received community treatment between visits 1 and 2. Three of these continued to receive community treatment between visits 2 and 3. A total of 17 different participants received treatment at some time. The number of treatment sessions for each participant was not recorded. One child was placed on a stimulant medication after visit 1, and one child was placed on a selective serotonin reuptake inhibitor plus an a-adrenergic agonist after visit 2. Procedure The Tulane University Committee on the Use of Human Subjects approved this study. When participants arrived at the laboratory, the study was verbally explained to the caregivers, and they were given a consent form to read. Written informed consent was obtained. Voluntary assent was obtained from children. A variety of measures were obtained at the visit. Data are reported only on the measures listed above. From the index trauma to visit 1, the mean length of time was 11.2 months (SD = 11.0), the median was 7.5 months, and the range was 2–52 months. We attempted to reassess participants at 12-month intervals thereafter. The mean length of time between visits 1 and 2 was 13.7 months (SD = 2.9), the median was 14 months, and the range was 7–19 months. The mean length of time between visits 2 and 3 was 13.1 months (SD = 2.7), the median was 12 months, and the range was 9–20 months. Data Analysis Fisher exact test was used to test whether children who were diagnosed with PTSD at the follow-up visits had greater proportions that had been diagnosed with PTSD at visit 1. Linear regression tests were used to test whether a diagnosis of PTSD at visit 1 predicted functional impairment in the follow-up assessments. A mixed-models analysis was used to examine the longitudinal course of the number of PTSD symptoms over all three visits. This method allowed for the use of data from all participants because some had missing data at visits 2 and 3. A compound symmetry covariance structure was used. Where multiple tests were conducted, corrections for the a level of significance were not used because these analyses were exploratory. Spearman correlations were used to examine the bivariate relationships between hyperarousal and EN. The binomial distribution was used to calculate the probability that the rates of impairment were different from the rates of PTSD diagnosis.
RESULTS Predictive Validity of Visit 1 PTSD Diagnosis for 1- and 2-Year PTSD Diagnoses
Neither the presence of the PTSD diagnosis nor the number of PTSD symptoms at visit 1 was significantly related to child age, type of trauma, gender, race, maternal age, maternal employment, or the number of parents in the home. The rates of diagnosis of PTSD at each
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visit were 25.8% at visit 1 (16 diagnosed of 62), 23.4% at visit 2 (11 of 47), and 22.9% at visit 3 (8 of 35) (Table 1). Overall, 38.7% (n = 24) were diagnosed with PTSD at some point during the 2 years of this study. The tracking of subjects and diagnoses (and no diagnoses) at each visit is shown in Figure 1. Of the 16 children who were diagnosed at visit 1, the portion that was retained at visit 2 had a 30.8% rate of rediagnosis with PTSD, and the portion that was retained at visit 3 had a 50% rate of rediagnosis. Of the 46 children who were not diagnosed at visit 1, the portion that was retained at visit 2 had a 79.4% rate of not being diagnosed again, and the portion that was retained at visit 3 had a 91.3% rate of not being diagnosed again. The children who were diagnosed with PTSD at visit 2 did not have a significantly higher proportion of diagnoses of PTSD at visit 1 compared with the children who were not diagnosed with PTSD at visit 2 (Fisher exact test, p = .47, two sided). The children who were diagnosed with PTSD at visit 3, however, had a significantly higher proportion of diagnoses of PTSD at visit 1 as compared with the children who were not diagnosed with PTSD at visit 3 (Fisher exact test, p < .05, two sided). These findings suggest that there was greater stability of diagnostic status between visits 1 and 3 than between visits 1 and 2. Thus, visits 1 to 3 stability partially supports the predictive validity of the alternative method of diagnosing PTSD in preschool children. The lack of statistically significant stability between visits 1 and 2 seemed to be largely the result of seven participants who were not diagnosed at visit 1 with PTSD but were newly diagnosed at visit 2. Compared with the rest of the visit 2 sample, these seven children were significantly younger at visit 2 (52.7 versus 72.1 months, t = 2.96, df = 45, p < .01) and had a shorter length of time between their trauma and their visit 2 (19.9 versus 24.5
months, t = 2.55 for unequal variances, df = 26.5, p < .05). Six of the seven were boys, but this difference did not reach statistical significance (Fisher exact test, p = .10, two sided). Most important, five of the seven experienced new stressors between visits 1 and 2, including one who endured the suicide of a stepfather, one who endured the death of a close uncle, and three who witnessed new domestic violence. A sixth subject had extensive facial scarring from his original trauma and was being evaluated by plastic surgeons. In contrast, of the 40 other participants at visit 2 who were not newly diagnosed, only two endured new stressors in the interim. None of the participants diagnosed at visit 1 experienced new traumas between visits 1 and 2. Only one child (who had PTSD at all three visits) experienced a new major stressor between visits 2 and 3. Predictive Validity of Visit 1 PTSD Diagnosis for 1- and 2-Year Functional Impairment
The visit 1 PTSD group was impaired in significantly more domains 1 year later at visit 2 (2.2 of 5 possible) as compared with the visit 1 No-PTSD group (0.5) in a simple linear regression test (F = 23.21, df = 1, 45, p < .0001, R2 = 0.34). When child emotional distress was allowed as a sixth possible domain of impairment, the significant relationship was not changed, but the amount of variance accounted for actually decreased (R2 = 0.21). The visit 1 PTSD group was also impaired in significantly more domains 2 years later at visit 3 (3.1 of 5 possible) as compared with the visit 1 No-PTSD group (1.7; F = 6.82, df = 1, 33, p < .05, R2 = 0.17). When child emotional distress was allowed as a sixth possible domain of impairment, the significant relationship was not changed, and the amount of variance accounted for slightly decreased (R2 = 0.15).
TABLE 1 Rates of PTSD Diagnosis and Criteria B, C, and D at All Three Visits Visit 1 (n = 62) Visit 2 (n = 47) DSM-IV PTSD diagnosis Alternative PTSD diagnosis Reexperiencing Avoidance/numbinga Hyperarousal
0% 25.8% 67.7% 38.7% 45.2%
(n (n (n (n
= = = =
16) 42) 24) 28)
2.1% 23.4% 48.9% 44.7% 34.0%
(n (n (n (n (n
= = = = =
1) 11) 23) 21) 16)
Visit 3 (n = 35) 11.4% 22.9% 37.1% 42.9% 51.4%
(n (n (n (n (n
= = = = =
4) 8) 13) 15) 18)
Note: PTSD = posttraumatic stress disorder. The threshold for avoidance/numbing is the alternative method threshold of one symptom.
a
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Fig. 1 Retention of participants and PTSD/No-PTSD status at the three visits. PTSD = posttraumatic stress disorder.
Course of Total PTSD Symptomatology
We examined the course of total PTSD symptomatology at each visit in a mixed-models analysis. We incorporated into this analysis a test for the effect of time from trauma to visit 1 because there was a wide range and a test for the effect of treatment because 17 subjects received community treatment. The first model included PTSD diagnosis at visit 1 as the group variable (PTSD versus No-PTSD at visit 1), time between visits (the time variable) as a continuous variable (in months), and a group 3 time interaction term. The PTSD group had significantly higher levels of PTSD symptoms than did the No-PTSD group (F = 15.89, df = 1, 60, p < .001). There was no change in symptoms over time (F = 2.61, df = 1, 80, p = .11) and no significant interaction of group with time (F = 0.0, df = 1, 80, p = .97). A second model was tested with length of time from the trauma to the first assessment added as a predictor variable to determine whether this was a potential confounder. Time from the trauma was not significant, and the significance of the findings in the first model equation was not substantially changed. A third model was tested with community treatment added as a predictor variable to determine whether this was a potential confounder. Community treatment was not significant, and, again, the significance of the findings in the first model equation was not substantially altered. Thus, we concluded that the visit 1 PTSD group continued to have significantly more symptoms than the No-PTSD group over 2 years, there was no significant decrease in symptoms over 2 years, and there were no effects for time from trauma to assessment or for community treatment. A final model was created by dropping the group with time interaction term from the first model because it was nonsignificant, and the parameter estimates from this model equation were then used to create a graph to visualize the course of the number of PTSD symp-
toms corrected for the time from trauma. Three time points were chosen to approximate the three visits in our study: 4 months posttrauma approximated visit 1, 16 months posttrauma approximated visit 2, and 28 months posttrauma approximated visit 3 (Fig. 2). It is apparent that, at 4 months posttrauma, the group that was diagnosed with PTSD at visit 1 had an estimated mean of 6.1 PTSD symptoms and the nondiagnosed group had a mean of 2.7 PTSD symptoms. This number of symptoms did not diminish by even as much as one symptom over 2 years for either group. A power analysis indicated that to detect a decrease of one symptom for group means between two visits, at a significance level of 0.05 and a desired power of 0.80, a sample size of 78 is needed. To detect a decrease of two symptoms between visits, however, a sample size of 20 is needed. Thus, this study had sufficient power to detect a two-symptom or more change but not a one-symptom change.
Fig. 2 Number of PTSD symptoms over time from a mixed-models analysis equation adjusted for time from trauma. Visit 1 in this study is approximated by 4 months posttrauma, visit 2 by 16 months posttrauma, and visit 3 by 28 months posttrauma.
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Course of PTSD Criteria B, C, and D
The courses of each PTSD symptom criterion were also examined with mixed-models analyses to test for changes over time and between groups. The presence of reexperiencing symptoms (criterion B) decreased substantially over time, from being present in 67.7% of the sample at visit 1 to 37.1% at visit 3 (Table 1). A mixed-models analysis showed that the visit 1 PTSD group had significantly more reexperiencing symptoms than the visit 1 No-PTSD group (F = 8.23, df = 1,60, p < .01). The number of reexperiencing symptoms significantly decreased with time (F = 23.11, df = 1, 80, p < .0001; Fig. 3). There was no significant interaction of PTSD status with time (F = 0.13, df = 1,80, p = .72). There was no effect of time from trauma when this was added in a separate model. There was neither an effect of community treatment nor an effect of a community treatment with time interaction. The visit 1 PTSD group had significantly more symptoms of avoidance/numbing (criterion C) than the visit 1 No-PTSD group (F = 4.02, df = 1, 60, p < .05). The number of avoidance/numbing symptoms significantly increased with time (F = 9.24, df = 1, 80, p < .01), but there was a significant interaction of visit 1 PTSD status with time (F = 4.85, df =1, 80, p < .05). The visit 1 PTSD group increased their number of avoidance/numbing symptoms at a greater rate than did the visit 1 No-PTSD group (Fig. 3). There were no effects of time from trauma, community treatment, or com-
munity treatment with time interaction when these were added in separate models. The visit 1 PTSD group had significantly more hyperarousal symptoms (criterion D) than did the visit 1 NoPTSD group (F = 12.23, df = 1, 60, p < .001). There was no significant change in hyperarousal symptoms over time (F = 3.28, df = 1, 80, p = .074), and there was no significant interaction of visit 1 PTSD status with time (F = 1.44, df = 1, 80, p = 23; Fig. 3). There were no effects of time from trauma, community treatment, or community treatment with time interaction when these were added in separate models. Overall, the earlier finding of no significant change in PTSD symptoms over time appears more complicated when examined by criteria B, C, and D. The significant decrease in reexperiencing is ‘‘balanced’’ by the significant increase in avoidance/numbing, and the rate of increase in avoidance/numbing over time is greater for the visit 1 PTSD group as compared with the visit 1 NoPTSD group. We attempted to replicate in older populations the finding that chronic arousal symptoms (criterion D) may cause EN symptoms. The fist step was to examine the correlations between hyperarousal at all three visits and the EN variables at all three visits. The correlations between visit 1 hyperarousal and visit 1 EN (r = 0.06) and visit 2 EN (r = 0.14) and visit 3 EN (r = 0.31) were neither large nor significant. Visit 2 hyperarousal correlated significantly with visit 2 EN (r = 0.36, p < .05) but not with visit 3 EN (r = 0.23). Visit 3 hyperarousal did not correlate significantly with visit 3 EN (0.29). These largely nonsignificant relationships precluded any further analysis and did not support the theory that chronic arousal symptoms cause numbing symptoms in this population. Impaired but Not Diagnosed
Fig. 3 Longitudinal courses of criteria B, C, and D symptoms in the groups that were diagnosed (visit 1 PTSD) and not diagnosed (visit 1 No-PTSD) with PTSD at visit 1.
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At visit 2, according to parent ratings, significantly more children were impaired in at least one domain (48.9%) than had the full diagnosis of PTSD (23.4%; binomial test, p < .0001). At visit 3, this discrepancy between rates of impairment (74.3%) and PTSD diagnosis (22.9%) was even more pronounced (binomial test, p < .0001; Fig. 4). The significance of these findings did not change if child distress was allowed as a sixth domain of functional impairment. The most common domain of impairment at visit 2 was child distress (34%), followed by annoyed parents
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Fig. 4 Percentages of children with PTSD and impairment in 1, 2, 3, 4, or 5 domains at visits 2 and 3.
(32%), restricted participation in activities with the family (26%), restricted participation with peers (19%), annoyed teachers (17%), and school work (6%). The most common domain of impairment at visit 3 was parent annoyed (66%), restricted activities with the family (51%), child distress (40%), restricted participation with peers (37%), school work (31%), and teacher annoyed (29%). DISCUSSION
This first longitudinal study of PTSD diagnosis and symptomatology in preschool children makes several contributions. First, these findings support the predictive validity of the alternative method for diagnosing PTSD in infant and preschool children. Children diagnosed with PTSD at visit 1 predicted significantly more symptoms of PTSD and functional impairment in more domains over the course of 2 years than did the No-PTSD group. Second, the longitudinal analysis of the number of PTSD symptoms demonstrated that symptoms did not remit over 2 years, even with community treatment. This finding was unexpected. The majority of previous studies, albeit in older populations, found that PTSD rates and symptoms decrease with time but do not completely disappear (Breslau, 2001), although there have been exceptions, such as severe burns in adults (Madianos et al., 2001) and children terrified by brush fire (McFarlane, 1987). This suggests the disturbing possibility that young children who are vulnerable to developing PTSD after traumas are doubly vulnerable to a more unremitting course of illness. This raises questions about neurobiological vulnerability to traumatic experiences in young children with rapidly developing brains.
Third, as has been shown repeatedly in adult studies, the reexperiencing (criterion B) symptoms were more prominent initially and then faded relatively more with time (Blank, 1993). In contrast to previous studies, avoidance/numbing (criterion C) symptoms increased over time, particularly for the visit 1 PTSD group. Despite this increase in avoidance/numbing symptoms over time, we were not able to replicate the previous finding that chronic expression of hyperarousal seemed to drive the development of EN (a subset of avoidance/numbing; Flack et al., 2000; Litz et al., 1997; Weems et al., 2003). Fourth, substantially more children were considered functionally impaired by their caregivers than were diagnosed with PTSD. The rates of impairment were two to three times the rates of diagnosis, and the discrepancy appeared to grow between visits 2 and 3. This finding is consistent with the finding by Angold et al. (1999) in their large epidemiological study of 9- to 13-year-old children that 8.9% of non–mental health services users and 21.3% of service users were impaired but not diagnosed with any type of disorder. They suggested that these children would qualify for not otherwise specified (NOS) categories but that greater attention was needed to operationalize the NOS categories. Similarly, we hope that our finding stimulates attention on how to best operationalize the designations of children who are impaired and need treatment. Limitations
Assessment of avoidance/numbing symptoms may not be generalizable to older populations because of either the inherent developmental barriers that seem to prevent young children from developing all of these items (Scheeringa et al., 2003) or the absence of self-report for these relatively more abstract and internalized items or both. This was not a help-seeking cohort, so the results may not be generalizable to clinic populations. The types of traumatic events were heterogeneous in this sample and may not be generalizable to more homogeneous cohorts. Clinical Implications
PTSD symptomatology and associated functional impairment do not remit spontaneously in this young population. Contrary to examples of plasticity and resiliency in abnormal development, such as recovery from hemispherectomies to treat intractable epilepsy
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(Peacock, 1995) and popular notions that young children are more resilient, the data for PTSD in early childhood after serious trauma suggest otherwise. This ought to focus attention in the field on developing effective and accessible treatment for traumatized young children. These data highlight the need to treat the avoidance and numbing symptomatology in particular and to provide treatment as early as possible in children’s lives. Given the acknowledged importance of caregiving relationships for young children, for children who experience abuse and neglect from their caregivers, intervention plans also ought to consider placing children with supportive caregivers. No effective treatment for preschool children who experienced all types of traumatic events has yet been studied for efficacy. There is a substantial case study literature on the treatment of PTSD in preschool children (Gaensbauer and Siegel, 1995), and the efficacy of manual-based cognitivebehavioral treatment protocols for sexual abuse trauma has been demonstrated (Cohen and Mannarino, 1996), but an evidence-based protocol for all types of traumatic events is clearly needed. Given the finding in this study that two to three times as many children are functionally impaired from PTSD-related symptoms as are diagnosed, treatment ought not be restricted to only those who meet the diagnostic threshold. This ought to inspire thoughtful considerations for primary care providers who make referrals, frontline mental health clinicians who conduct triage and intake, and health insurance that sets restrictions on diagnosis-driven access to care. Disclosure: The authors have no financial relationships to disclose. REFERENCES Angold A, Costello E, Farmer E (1999), Impaired but undiagnosed. J Am Acad Child Adolesc Psychiatry 38:129–137 Blank A (1993), The longitudinal course of posttraumatic stress disorder. In: Posttraumatic Stress Disorder: DSM-IV and Beyond, Davidson J, Foa E, eds. Washington, DC: American Psychiatric Press, pp 3–22 Breslau N (2001), Outcomes of posttraumatic stress disorder. J Clin Psychiatry 62:55–59 Cohen J, Mannarino A (1996), A treatment outcome study for sexually abused preschool children: initial findings. J Am Acad Child Adolesc Psychiatry 35:42–50
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