BACKGROUND: Retrospective studies show that childhood adversity is associated with systemic inflammation in adulthood. Few prospective studies have examined whether childhood adversity influences inflammation in an observable manner during childhood or adolescence and if these effects are sustained over time. METHODS: Using longitudinal data from the Avon Longitudinal Study of Parents and Children, we examined associations between acute adverse events at seven time points prior to age 8 and inflammation at ages 10 and 15. Inflammatory markers at age 10 included interleukin-6 (IL-6; N=4655) and C-reactive protein (CRP; N=4647), and CRP was measured again at age 15 (N=3286). We further evaluated whether body mass index (BMI), depression, or cigarette smoking mediated associations between adverse events and inflammation. RESULTS: Adverse events in middle childhood (occurring between ages 6 to 8), as well as cumulative adversity from birth to 8 years, were associated with higher levels of IL-6 and CRP at age 10. Adverse events reported in early childhood (1.5years) or middle childhood, and cumulative adversity from birth through 8years predicted increased levels of CRP at age 15, and these associations persisted after adjustment for CRP at age 10. Some, but not all, of these associations were mediated by BMI. CONCLUSIONS: This study documents that exposure to adverse events prior to age 8 is associated with elevated inflammation at age 10 and in mid-adolescence. These findings provide prospective evidence for a biological mechanism by which early experiences may shape long-term health. Future studies with earlier assessments of inflammation are necessary in order to elucidate potential sensitive periods and mechanisms that link childhood adversity to later disease vulnerability.
BACKGROUND: Although the proposal for a dissociative subtype of posttraumatic stress disorder (PTSD) in DSM-5 is supported by considerable clinical and neurobiological evidence, this evidence comes mostly from referred samples in Western countries. Cross-national population epidemiologic surveys were analyzed to evaluate generalizability of the subtype in more diverse samples. METHODS: Interviews were administered to 25,018 respondents in 16 countries in the World Health Organization World Mental Health Surveys. The Composite International Diagnostic Interview was used to assess 12-month DSM-IV PTSD and other common DSM-IV disorders. Items from a checklist of past-month nonspecific psychological distress were used to assess dissociative symptoms of depersonalization and derealization. Differences between PTSD with and without these dissociative symptoms were examined across a variety of domains, including index trauma characteristics, prior trauma history, childhood adversity, sociodemographic characteristics, psychiatric comorbidity, functional impairment, and treatment seeking. RESULTS: Dissociative symptoms were present in 14.4% of respondents with 12-month DSM-IV/Composite International Diagnostic Interview PTSD and did not differ between high and low/middle income countries. Symptoms of dissociation in PTSD were associated with high counts of re-experiencing symptoms and net of these symptom counts with male sex, childhood onset of PTSD, high exposure to prior (to the onset of PTSD) traumatic events and childhood adversities, prior histories of separation anxiety disorder and specific phobia, severe role impairment, and suicidality. CONCLUSION: These results provide community epidemiologic data documenting the value of the dissociative subtype in distinguishing a meaningful proportion of severe and impairing cases of PTSD that have distinct correlates across a diverse set of countries.
BACKGROUND: A growing literature indicates that genetic variation, in combination with adverse early life experiences, shapes risk for later mental illness. Recent work also suggests that molecular variation at the ADCYAP1R1 locus is associated with posttraumatic stress disorder (PTSD) in women. We sought to test whether childhood maltreatment (CM) interacts with ADCYAP1R1 genotype to predict PTSD in women. METHODS: Data were obtained from 495 adult female participants from the Detroit Neighborhood Health Study. Genotyping of rs2267735, an ADCYAP1R1 variant, was conducted via TaqMan assay. PTSD, depression, and CM exposure were assessed via structured interviews. Main and interacting effects of ADCYAP1R1 and CM levels on past month PTSD and posttraumatic stress (PTS) severity were examined using logistic regression and a general linear model, respectively. As a secondary analysis, we also assessed main and interacting effects of ADCYAP1R1 and CM variation on risk of past-month depression diagnosis and symptom severity. RESULTS: No significant main effects were observed for ADCYAP1R1 genotype on either PTSD/PTS severity. In contrast, a significant ADCYAP1R1 × CM interaction was observed for both past month PTSD and PTS severity, with carriers of the "C" allele showing enhanced risk for these outcomes among women exposed to CM. No significant main or interaction effects were observed for past month depression/depression severity. CONCLUSIONS: Genetic variation at the ADCYAP1R1 locus interacts with CM to shape risk of later PTSD, but not depression, among women. The molecular mechanisms contributing to this interaction require further investigation.
BACKGROUND: Posttraumatic stress disorder (PTSD) is a debilitating anxiety disorder. Surveys of the general population suggest that while 50-85% of Americans will experience a traumatic event in their lifetime, only 2-50% will develop PTSD. Why some individuals develop PTSD following trauma exposure while others remain resilient is a central question in the field of trauma research. For more than half a century, the role of genetic influences on PTSD has been considered as a potential vulnerability factor. However, despite the exponential growth of molecular genetic studies over the past decade, limited progress has been made in identifying true genetic variants for PTSD. METHODS: In an attempt to aid future genome wide association studies (GWAS), this paper presents a systematic review of 28 genetic association studies of PTSD. Inclusion criteria required that 1) all participants were exposed to Criterion A traumatic events, 2) polymorphisms of relevant genes were genotyped and assessed in relation to participants' PTSD status, 3) quantitative methods were used, and 4) articles were published in English and in peer-reviewed journals. In the examination of these 28 studies, particular attention was given to variables related to trauma exposure (e.g. number of traumas, type of trauma). RESULTS: Results indicated that most articles did not report on the GxE interaction in the context of PTSD or present data on the main effects of E despite having data available. Furthermore, some studies that did consider the GxE interaction had significant findings, underscoring the importance of examining how genotypes can modify the effect of trauma on PTSD. Additionally, results indicated that only a small number of genes continue to be studied and that there were marked differences in methodologies across studies, which subsequently limited robust conclusions. CONCLUSIONS: As trauma exposure is a necessary condition for the PTSD diagnosis, this paper identifies gaps in the current literature as well as provides recommendations for how future GWAS studies can most effectively incorporate trauma exposure data in both the design and analysis phases of studies.
BACKGROUND: Child maltreatment is a potent risk factor for psychopathology. Although the developmental timing of first exposure to maltreatment is considered important in shaping risk of future psychopathology, no consensus exists on whether earlier or later exposures are more deleterious. This study examines whether age at first exposure to abuse is associated with subsequent depression and suicidal ideation. METHODS: Data were drawn from the National Longitudinal Study of Adolescent Health (n = 15,701). Timing of first maltreatment exposure was classified using: (1) a crude measure capturing early childhood (ages 0-5), middle childhood (ages 6-10), or adolescence (ages 11-17); and (2) a refined measure capturing infancy (ages 0-2), preschool (ages 3-5), latency (ages 6-8), prepubertal (ages 9-10), pubertal (ages 11-13), or adolescence (ages 14-17). We examined whether timing of first exposure was associated with depression and suicidal ideation in early adulthood in the entire sample and among those exposed to maltreatment. RESULTS: Respondents exposed to abuse, particularly physical abuse, at any age had a higher odds of depression and suicidal ideation in young adulthood than non-maltreated respondents. Among maltreated respondents, exposure during early childhood (ages 0-5), particularly preschool (ages 3-5), was most strongly associated with depression. Respondents first exposed to physical abuse during preschool had a 77% increase in the odds of depression and those first exposed to sexual abuse during early childhood had a 146% increase in the odds of suicidal ideation compared to respondents maltreated as adolescents. CONCLUSIONS: Developmental timing of first exposure to maltreatment influences risk for depression and suicidal ideation. Whether these findings are evidence for biologically based sensitive periods requires further study.
Worry is the defining feature of generalized anxiety disorder (GAD), and rumination is a central process in depression. GAD and depression are highly comorbid, and worry and rumination reflect similar perseverative cognitive processes. Prior studies have largely assessed these emotion regulation strategies at the trait level, which has resulted in a limited understanding of their phasic characteristics, including associated physiological processes. We addressed this limitation by examining the relationship between spontaneous state-level worry and rumination and heart rate variability (HRV)-a physiological measure of emotion regulation-in response to emotion-eliciting film clips. We found differential associations between worry and rumination in relation to HRV, such that, worry was more consistently associated with HRV across emotional contexts than rumination was. Findings highlight functional distinctions between worry and rumination that have implications for understanding their associations with mood and anxiety disorders and, more broadly, for theories of emotion regulation and psychopathology.
OBJECTIVES: We examine gender differences in population rates of various types of interpersonal violence in a U.S. national sample and investigate gender as a moderator of the associations between interpersonal violence and lifetime mental disorders and suicide attempts. METHODS: Data were drawn from the National Comorbidity Survey-Replication study; 5,692 women and men completed interviews assessing lifetime exposure to nine types of interpersonal violence, Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) mental health diagnoses, and suicide attempts. RESULTS: Approximately 46% of women and 42% of men reported one or more types of interpersonal violence. Women were more likely to experience kidnapping, physical assault by an intimate partner, rape, sexual assault, and stalking, whereas men were more likely to experience mugging or physical assault by someone other than parents or an intimate partner. Interpersonal violence was associated with risk for many mental disorders and attempted suicide. Although women were at higher risk for several forms of interpersonal violence, the impact of interpersonal violence on mental health outcomes did not vary by gender. CONCLUSIONS: It is clearly important to identify and provide mental health treatment to women after interpersonal violence exposure. Findings also underscore the need for prevention and intervention efforts for women and men, including routine screening for interpersonal violence by health care providers and appropriate treatment to address mental health conditions.
BACKGROUND: Although irritability is a core symptom of DSM-IV major depressive disorder (MDD) for youth but not adults, clinical studies find comparable rates of irritability between nonbipolar depressed adults and youth. Including irritability as a core symptom of adult MDD would allow detection of depression-equivalent syndromes with primary irritability hypothesized to be more common among males than females. We carried out a preliminary examination of this issue using cross-national community-based survey data from 21 countries in the World Mental Health (WMH) Surveys (n = 110,729). METHODS: The assessment of MDD in the WHO Composite International Diagnostic Interview includes one question about persistent irritability. We examined two expansions of the definition of MDD involving this question: (1) cases with dysphoria and/or anhedonia and exactly four of nine Criterion A symptoms plus irritability; and (2) cases with two or more weeks of irritability plus four or more other Criterion A MDD symptoms in the absence of dysphoria or anhedonia. RESULTS: Adding irritability as a tenth Criterion A symptom increased lifetime prevalence by 0.4% (from 11.2 to 11.6%). Adding episodes of persistent irritability increased prevalence by an additional 0.2%. Proportional prevalence increases were significantly higher, but nonetheless small, among males compared to females. Rates of severe role impairment were significantly lower among respondents with this irritable depression who did not meet conventional DSM-IV criteria than those with DSM-IV MDD. CONCLUSION: Although limited by the superficial assessment in this single question on irritability, results do not support expanding adult MDD criteria to include irritable mood.
BACKGROUND: Potentially traumatic events (PTEs) are common in the population, yet, the impact of total burden and specific types of PTEs on physical health has not been systematically investigated. METHODS: Data were drawn from the Detroit Neighborhood Health Study, a community sample of predominately African Americans living in Detroit, Michigan, interviewed in 2008-2009 (N = 1,547) and in 2009-2010 (N = 1,054). Kaplan-Meier and Cox proportional hazards models were used. RESULTS: Respondents with the highest levels of PTE exposure (8+ events) had an average age of adverse physical health condition diagnosis that was 15 years earlier than respondents with no exposure. There was a monotonic relation between number of PTEs and arthritis risk. Compared to those who reported no lifetime events, respondents with 1-2, 3-4, 5-7, and 8+ traumatic events had 1.06, 1.12, 1.73, and 2.44 times the hazard of arthritis. Assaultive violence (HR = 1.7; 95% CI 1.2-2.3) and other threats to physical integrity (HR = 1.5, 95% CI 1.1-2.1) were particularly strong risk factors for arthritis. CONCLUSIONS: These results provide novel evidence linking PTEs, particularly those involving violence and threat to life, to elevated risk for arthritic conditions. Efforts to prevent or mitigate traumatic event exposures may have a broad range of benefits for health.
CONTEXT: Although suicide is the third leading cause of death among US adolescents, little is known about the prevalence, correlates, or treatment of its immediate precursors, adolescent suicidal behaviors (ie, suicide ideation, plans, and attempts). OBJECTIVES: To estimate the lifetime prevalence of suicidal behaviors among US adolescents and the associations of retrospectively reported, temporally primary DSM-IV disorders with the subsequent onset of suicidal behaviors. DESIGN: Dual-frame national sample of adolescents from the National Comorbidity Survey Replication Adolescent Supplement. SETTING: Face-to-face household interviews with adolescents and questionnaires for parents. PARTICIPANTS: A total of 6483 adolescents 13 to 18 years of age and their parents. MAIN OUTCOME MEASURES: Lifetime suicide ideation, plans, and attempts. RESULTS: The estimated lifetime prevalences of suicide ideation, plans, and attempts among the respondents are 12.1%, 4.0%, and 4.1%, respectively. The vast majority of adolescents with these behaviors meet lifetime criteria for at least one DSM-IV mental disorder assessed in the survey. Most temporally primary (based on retrospective age-of-onset reports) fear/anger, distress, disruptive behavior, and substance disorders significantly predict elevated odds of subsequent suicidal behaviors in bivariate models. The most consistently significant associations of these disorders are with suicide ideation, although a number of disorders are also predictors of plans and both planned and unplanned attempts among ideators. Most suicidal adolescents (\textgreater80%) receive some form of mental health treatment. In most cases (\textgreater55%), treatment starts prior to onset of suicidal behaviors but fails to prevent these behaviors from occurring. CONCLUSIONS: Suicidal behaviors are common among US adolescents, with rates that approach those of adults. The vast majority of youth with suicidal behaviors have preexisting mental disorders. The disorders most powerfully predicting ideation, though, are different from those most powerfully predicting conditional transitions from ideation to plans and attempts. These differences suggest that distinct prediction and prevention strategies are needed for ideation, plans among ideators, planned attempts, and unplanned attempts.
Rumination is a well-established risk factor for the onset of major depression and anxiety symptomatology in both adolescents and adults. Despite the robust associations between rumination and internalizing psychopathology, there is a dearth of research examining factors that might lead to a ruminative response style. In the current study, we examined whether social environmental experiences were associated with rumination. Specifically, we evaluated whether self-reported exposure to stressful life events predicted subsequent increases in rumination. We also investigated whether rumination served as a mechanism underlying the longitudinal association between self-reported stressful life events and internalizing symptoms. Self-reported stressful life events, rumination, and symptoms of depression and anxiety were assessed in 2 separate longitudinal samples. A sample of early adolescents (N = 1,065) was assessed at 3 time points spanning 7 months. A sample of adults (N = 1,132) was assessed at 2 time points spanning 12 months. In both samples, self-reported exposure to stressful life events was associated longitudinally with increased engagement in rumination. In addition, rumination mediated the longitudinal relationship between self-reported stressors and symptoms of anxiety in both samples and the relationship between self-reported life events and symptoms of depression in the adult sample. Identifying the psychological and neurobiological mechanisms that explain a greater propensity for rumination following stressors remains an important goal for future research. This study provides novel evidence for the role of stressful life events in shaping characteristic responses to distress, specifically engagement in rumination, highlighting potentially useful targets for interventions aimed at preventing the onset of depression and anxiety.
OBJECTIVE: Although schools are identified as critical for detecting youth mental disorders, little is known about whether the number of mental health providers and types of resources that they offer influence student mental health service use. Such information could inform the development and allocation of appropriate school-based resources to increase service use. This article examines associations of school resources with past-year mental health service use among students with 12-month DSM-IV mental disorders. METHOD: Data come from the U.S. National Comorbidity Survey Adolescent Supplement (NCS-A), a national survey of adolescent mental health that included 4,445 adolescent-parent pairs in 227 schools in which principals and mental health coordinators completed surveys about school resources and policies for addressing student emotional problems. Adolescents and parents completed the Composite International Diagnostic Interview and reported mental health service use across multiple sectors. Multilevel multivariate regression was used to examine associations of school mental health resources and individual-level service use. RESULTS: Nearly half (45.3%) of adolescents with a 12-month DSM-IV disorder received past-year mental health services. Substantial variation existed in school resources. Increased school engagement in early identification was significantly associated with mental health service use for adolescents with mild/moderate mental and behavior disorders. The ratio of students to mental health providers was not associated with overall service use, but was associated with sector of service use. CONCLUSIONS: School mental health resources, particularly those related to early identification, may facilitate mental health service use and may influence sector of service use for youths with DSM disorders.
BACKGROUND: Emerging evidence from general population studies suggests that lesbian, gay, and bisexual (LGB) adults are more likely to experience adverse cardiovascular outcomes relative to heterosexuals. No studies have examined whether sexual orientation disparities exist in biomarkers of early cardiovascular disease risk. PURPOSE: To determine whether sexual orientation disparities in biomarkers of early cardiovascular risk are present among young adults. METHODS: Data come from Wave IV (2008-2009) of the National Longitudinal Study for Adolescent Health (N=12,451), a prospective nationally representative study of U.S. adolescents followed into young adulthood (mean age=28.9 years). A total of 520 respondents identified as lesbian, gay, or bisexual. Biomarkers included C-reactive protein, glycosylated hemoglobin, systolic and diastolic blood pressure, and pulse rate. Analyses were conducted in 2012. RESULTS: In gender-stratified models adjusted for demographics (age, race/ethnicity); SES (income, education); health behaviors (smoking, regular physical activity, alcohol consumption); and BMI, gay and bisexual men had significant elevations in C-reactive protein, diastolic blood pressure, and pulse rate, compared to heterosexual men. Despite having more risk factors for cardiovascular disease, including smoking, heavy alcohol consumption, and higher BMI, lesbians and bisexual women had lower levels of C-reactive protein than heterosexual women in fully adjusted models. CONCLUSIONS: Evidence was found for sexual orientation disparities in biomarkers of cardiovascular risk among young adults, particularly in gay and bisexual men. These findings, if confirmed in other studies, suggest that disruptions in core physiologic processes that ultimately confer risk for cardiovascular disease may occur early in the life course for sexual-minority men.
Suicide is difficult to predict and prevent and remains a leading cause of death worldwide. Although soldiers historically have had a suicide rate well below that of the general population, the suicide rate among members of the U.S. Army has increased markedly over the past several years and now exceeds that of the general population. This paper reviews psychosocial factors known to be associated with the increased risk of suicidal behavior in general and describes how some of these factors may be especially important in understanding suicide among soldiers. Moving forward, the prevention of suicide requires additional research aimed at: (a) better describing when, where, and among whom suicidal behavior occurs, (b) using exploratory studies to discover new risk and protective factors, (c) developing new methods of predicting suicidal behavior that synthesize information about modifiable risk and protective factors from multiple domains, and (d) understanding the mechanisms and pathways through which suicidal behavior develops. Although the scope and severity of this problem is daunting, the increasing attention and dedication to this issue by the Armed Forces, scientists, and society provide hope for our ability to better predict and prevent these tragic outcomes in the future.
BACKGROUND: South Africa's unique history, characterised by apartheid, a form of constitutional racial segregation and exploitation, and a long period of political violence and state-sponsored oppression ending only in 1994, suggests a high level of trauma exposure in the general population. The aim of this study was to document the epidemiology of trauma and posttraumatic stress disorder (PTSD) in the South African general population. METHODS: The South African Stress and Health Study is a nationally representative survey of South African adults using the WHO's Composite International Diagnostic Interview (CIDI) to assess exposure to trauma and presence of DSM-IV mental disorders. RESULTS: The most common traumatic events were the unexpected death of a loved one and witnessing trauma occurring to others. Lifetime and 12-month prevalence rates of PTSD were 2.3% and 0.7% respectively, while the conditional prevalence of PTSD after trauma exposure was 3.5%. PTSD conditional risk after trauma exposure and probability of chronicity after PTSD onset were both highest for witnessing trauma. Socio-demographic factors such as sex, age and education were largely unrelated to PTSD risk. CONCLUSIONS: The occurrence of trauma and PTSD in South Africa is not distributed according to the socio-demographic factors or trauma types observed in other countries. The dominant role of witnessing in contributing to PTSD may reflect the public settings of trauma exposure in South Africa and highlight the importance of political and social context in shaping the epidemiology of PTSD.
OBJECTIVE: Although exposure to potentially traumatic experiences (PTEs) is common among youths in the United States, information on posttraumatic stress disorder (PTSD) risk associated with PTEs is limited. We estimate lifetime prevalence of exposure to PTEs and PTSD, PTE-specific risk of PTSD, and associations of sociodemographics and temporally prior DSM-IV disorders with PTE exposure, PTSD given exposure, and PTSD recovery among U.S. adolescents. METHOD: Data were drawn from 6,483 adolescent-parent pairs in the National Comorbidity Survey Replication Adolescent Supplement (NCS-A), a national survey of adolescents aged 13 through 17 years. Lifetime exposure to interpersonal violence, accidents/injuries, network/witnessing, and other PTEs was assessed along with DSM-IV PTSD and other distress, fear, behavior, and substance disorders. RESULTS: A majority (61.8%) of adolescents experienced a lifetime PTE. Lifetime prevalence of DSM-IV PTSD was 4.7% and was significantly higher among females (7.3%) than among males (2.2%). Exposure to PTEs, particularly interpersonal violence, was highest among adolescents not living with both biological parents and with pre-existing behavior disorders. Conditional probability of PTSD was highest for PTEs involving interpersonal violence. Predictors of PTSD among PTE-exposed adolescents included female gender, prior PTE exposure, and pre-existing fear and distress disorders. One-third (33.0%) of adolescents with lifetime PTSD continued to meet criteria within 30 days of interview. Poverty, U.S. nativity, bipolar disorder, and PTE exposure occurring after the focal trauma predicted nonrecovery. CONCLUSIONS: Interventions designed to prevent PTSD in PTE-exposed youths should be targeted at victims of interpersonal violence with pre-existing fear and distress disorders, whereas interventions designed to reduce PTSD chronicity should attempt to prevent secondary PTE exposure.
Intermittent explosive disorder (IED) is characterized by recurrent episodes of impulsive, uncontrollable aggression out of proportion to the severity of provoking agents. Few epidemiological studies have been carried out on the prevalence and correlates of IED. Data are reported here from the most recent and largest of these studies: the U.S. National Comorbidity Survey Replication (NCS-R) and the World Health Organization World Mental Health (WMH) surveys. These studies show that IED is a commonly occurring disorder that typically has an early age of onset, a persistent course, and strong comorbidity with a number of other usually secondary mental disorders. This disorder is almost twice as common among men as women. It is often associated with substantial distress and impairment. However, only a minority of people with IED obtain treatment for their uncontrollable anger. This combination of features makes IED an ideal target for early detection and intervention aimed at secondary prevention of anger attacks as well as primary prevention of secondary disorders.
Background. A defining feature of the US economic downturn of 2008–2010 was the alarming rate of home foreclosure. Although a substantial number of US households have experienced foreclosure since 2008, the effects of foreclosure on mental health are unknown. We examined the effects of foreclosure on psychiatric symptomatology in a prospective, population-based community survey. Method. Data were drawn from the Detroit Neighborhoods and Health Study (DNHS), waves 1 and 2 (2008–2010). A probability sample of predominantly African-American adults in Detroit, Michigan participated (n=1547). We examined the association between home foreclosure between waves 1 and 2 and increases in symptoms of DSM-IV major depression and generalized anxiety disorder (GAD). Results. The most common reasons for foreclosure were an increase in monthly payments, an increase in non-medical expenses and a reduction in family income. Exposure to foreclosure between waves 1 and 2 predicted symptoms of major depression and GAD at wave 2, controlling for symptoms at wave 1. Even after adjusting for wave 1 symptoms, sociodemographics, lifetime history of psychiatric disorder at wave 1 and exposure to other financial stressors between waves 1 and 2, foreclosure was associated with an increased rate of symptoms of major depression [incidence density ratio (IDR) 2.4, 95 % confidence interval (CI) 1.6–3.6] and GAD (IDR 1.9, 95 % CI 1.4–2.6). Conclusions. We provide the first prospective evidence linking foreclosure to the onset of mental health problems. These results, combined with the high rate of home foreclosure since 2008, suggest that the foreclosure crisis may have adverse effects on the mental health of the US population.
Background Interventions to treat mental disorders after natural disasters are important both for humanitarian reasons and also for successful post-disaster physical reconstruction that depends on the psychological functioning of the affected population. A major difficulty in developing such interventions, however, is that large between-disaster variation exists in the prevalence of post-disaster mental disorders, making it difficult to estimate need for services in designing interventions without carrying out a post-disaster mental health needs assessment survey. One of the daunting methodological challenges in implementing such surveys is that secondary stressors unique to the disaster often need to be discovered to understand the magnitude, type, and population segments most affected by post-disaster mental disorders. Methods This problem is examined in the current commentary by analyzing data from the WHO World Mental Health (WMH) Surveys. We analyze the extent to which people exposed to natural disasters throughout the world also experienced secondary stressors and the extent to which the mental disorders associated with disasters were more proximally due to these secondary stressors than to the disasters themselves. Results Lifetime exposure to natural disasters was found to be high across countries (4.4–7.5%). 10.7–11.4% of those exposed to natural disasters reported the occurrence of other related stressors (e.g. death of a loved one and destruction of property). A monotonic relationship was found between the number of additional stressors and the subsequent onset of mental disorders Conclusions These results document the importance of secondary stressors in accounting for the effects of natural disasters on mental disorders. Implications for intervention planning are discussed.