Overall, the present study suggests that exposure to a PTE is associated with a higher probability of psychiatric morbidity than no history of a PTE. More specifically, this study found that exposure at any age, that is, in childhood or adulthood, compared with no exposure to a PTE was significantly related to higher rates of a psychiatric disorder as well as dysthymic disorder, panic disorder, alcohol or drug use disorder, and antisocial personality disorder. Examining differences in prevalence rates of disorders between a PTE first experienced in childhood and one experienced in adulthood, this study found that, controlling for significant demographic variables among the 3 groups, panic disorder, agoraphobia, and any diagnosis were significantly more likely to be associated with childhood onset of a PTE than adult onset of a PTE. No study, to our knowledge, has examined differences in prevalence rates of a range of psychiatric disorders among these 3 groups of individuals. However, other surveys have generally found that individuals exposed to a PTE relative to individuals with no such exposure report elevated levels of comorbidity as well as high rates of panic disorder, alcohol or drug use disorders, and antisocial personality disorder [1
]. However, unlike the current study, these studies focused on specific PTEs or specific disorders.
This study found that panic disorder was significantly more likely to be associated with a PTE with childhood onset than a PTE with onset in adulthood, independent of the number of PTEs and demographic difference between the 2 groups (ie, age). When comparing rape and physical assault during childhood and adulthood and controlling for sex and number of traumas, the finding for panic disorder was duplicated. In addition, PTSD and agoraphobia were found to be significantly related to childhood rape and physical abuse relative to these experiences in adulthood. All 3 diagnoses (ie, panic disorder, agoraphobia, and PTSD) involve strong autonomic arousal, fear response, and fight-flight action tendencies. Early experiences with uncontrollable stressful events may lead to perceptions of lack of control and helplessness; vulnerability factors for the development of these disorder [29
]. Another study using a nonrepresentative sample also found that physical abuse and sexual assault in childhood rather than such an event in adulthood are more likely to predispose individuals to PTSD [17
]. Furthermore, research has consistently found that a history of childhood abuse increases susceptibility to lifetime PTSD (see reference [30
] for review). Likewise, exposure to childhood sexual abuse and physical abuse has been shown to be linked to increased rates of panic disorder in adults (eg, reference [31
]) and in a large unselected birth cohort of young people studied at the age of 21 years, even after adjustment for prospectively assessed confounding factors [29
]. Given the high levels of comorbidity of PTSD with panic disorder and agoraphobia [7
], it is possible that childhood rape and physical assault are associated with a constellation of symptoms that transcend a single diagnosis. Longitudinal prospective studies research should examine the temporal relationship of a range of childhood PTEs and trauma-related disorders and how these disorders might covary with one another.
The only other study, to our knowledge, that examined whether individuals exposed to childhood trauma (specifically sexual assault) were more likely to develop disorders than those exposed in adulthood found, in contrast to the current study, that childhood sexual assault was more likely to be followed by onset of depression and substance use disorder [16
]. Besides the obvious differences between the 2 studies in terms of trauma populations (childhood sexual assault vs general PTEs) and sites (Los Angeles vs Chile) as well as methodology (eg, DSM, Third Edition
, verse DSM-III-R
criteria, no assessment of PTSD) that might have accounted for discrepant findings, the study by Burnam et al [16
] did not control for the number of traumas.
Limitations of the present study warrant attention. The study, like most epidemiologic studies, did not use an in-depth or validated index of trauma or a complete list of PTEs, which may have diluted findings. Also, the study omitted disorders that we expect from prior clinical research to be more strongly associated with early trauma than trauma later in life, such as borderline personality disorder. Because this study was cross-sectional, a direct cause-effect relationship cannot be assumed between trauma exposure and subsequent disorders. Confounding factors, such as social, family, and contextual factors, or premorbid factors, such as a preexisting disorder or loss of parent, may account for both trauma exposure (as an adult or in childhood) and risk of certain disorders. The relationship between the trauma and disorder could also have been mediated by any of the aforementioned factors. Also, characteristics of the childhood trauma, which have been proposed to play a key role in the genesis of PTSD and other psychiatric disorders [13
], were not examined in the current study or the only study, to date, that compared first onset of trauma in childhood compared with first onset in adulthood. Because of inadequate statistical power, the present study was unable to examine if our results were duplicated when comparing child-only traumatized people (with no adult trauma) with adult-only traumatized people (with no child trauma). Another limitation was the reliance on retrospective data, recall of trauma in the distant past, which may be prone to inaccuracies. It also remains unknown if our findings will vary cross-culturally. The political violence of Chile that occurred from toward the end of 1970 until the late 1980s and the economic inequality that exists among Chileans relative to countries in North America might restrict the generalizability of our findings to other countries. Comparing findings on rates of psychiatric disorders in the National Comorbidity Survey conducted in the United States [7
] with findings in the present study, the rates of panic disorder are similar and the rates of agoraphobia are higher. Rates of alcohol use disorders, PTSD, and trauma exposure are considerably lower in Chile[34
]. Finally, although the present analyses controlled for demographic variables between trauma in childhood, in adulthood, and no trauma, correcting for these confounds may have eliminated true group differences. For example, early trauma often results in poorer school performance, and in this study (and others), lower education was related to alcohol or drug use. In our analyses, differences between first child and adult trauma for alcohol or drug use were no longer significant once we controlled for educational status.
Despite these limitations, the findings of this study, consistent with the extant empirical literature, demonstrate that a PTE at any time in an individual’s life is associated with psychiatric morbidity. Our study extends the literature in that our results suggest that panic disorder rather than a range of other psychiatric disorders is related to a PTE that first occurs in childhood as opposed to adulthood. Furthermore, individuals with childhood interpersonal trauma exposure are more likely to suffer from lifetime panic disorder, agoraphobia, or PTSD compared with those who experience interpersonal trauma as an adult. Research should examine the specificity of these disorders in relation to various types of childhood PTEs.