Intensive longitudinal assessment following index trauma to predict development of PTSD using machine learning.

There are significant challenges to identifying which individuals require intervention following exposure to trauma, and a need for strategies to identify and provide individuals at risk for developing PTSD with timely interventions. The present study seeks to identify a minimal set of trauma-related symptoms, assessed during the weeks following traumatic exposure, that can accurately predict PTSD. Participants were 2185 adults (Mean age=36.4 years; 64% women; 50% Black) presenting for emergency care following traumatic exposure. Participants received a 'flash survey' with 6-8 varying symptoms (from a pool of 26 trauma symptoms) several times per week for eight weeks following the trauma exposure (each symptom assessed ∼6 times). Features (mean, sd, last, worst, peak-end scores) from the repeatedly assessed symptoms were included as candidate variables in a CART machine learning analysis to develop a pragmatic predictive algorithm. PTSD (PCL-5 ≥38) was present for 669 (31%) participants at the 8-week follow-up. A classification tree with three splits, based on mean scores of nervousness, rehashing, and fatigue, predicted PTSD with an Area Under the Curve of 0.836. Findings suggest feasibility for a 3-item assessment protocol, delivered once per week, following traumatic exposure to assess and potentially facilitate follow-up care for those at risk.

Posttraumatic Stress Disorder and Risk of Systemic Lupus Erythematosus Among Medicaid Recipients.

OBJECTIVE: We studied posttraumatic stress disorder (PTSD), a severe trauma-related mental disorder, and systemic lupus erythematosus (SLE) risk in a large, diverse population enrolled in Medicaid, a US government-sponsored health insurance program for low-income individuals. METHODS: We identified SLE cases and controls among patients ages 18-65 years enrolled in Medicaid for ≥12 months in the 29 most populated US states from 2007 to 2010. SLE and PTSD case statuses were defined based on validated patterns of International Classification of Diseases, Ninth Revision codes. Index date was the date of the first SLE code. Controls had no SLE codes but had another inpatient or outpatient code on the index date and were matched 1:10 to cases by age, sex, and race. Conditional logistic regressions calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) for the association of PTSD with incident SLE, adjusting for smoking, obesity, oral contraceptive use, and other covariates. RESULTS: A total of 10,942 incident SLE cases were matched to 109,420 controls. The prevalence of PTSD was higher in SLE cases, at 10.74 cases of PTSD per 1,000 person-years (95% CI 9.37-12.31) versus 7.83 cases (95% CI 7.42-8.27) in controls. The multivariable-adjusted OR for SLE among those with PTSD was 2.00 (95% CI 1.64-2.46). CONCLUSION: In this large, racially and sociodemographically diverse US population, we found patients with a prior PTSD diagnosis had twice the odds of a subsequent diagnosis of SLE. Studies are necessary to clarify the mechanisms driving the observed association and to inform possible interventions.

Child socioeconomic status, childhood adversity and adult socioeconomic status in a nationally representative sample of young adults.

Introduction: Numerous studies have examined the consequences of childhood adversity (CA) and socioeconomic status (SES) for health over the life course. However, few studies have examined the relation between childhood SES and CA as well as the influence of CA on adult SES. The objective of this study was to examine direct and indirect associations between childhood SES, CA and adult SES. Methods: Participants in the National Longitudinal Study of Adolescent to Adult Health, (N = 6844) reported on nine CA experiences. Childhood SES was characterized as a composite measure of parental highest education level, median household income, and parental occupational status. Adult SES was characterized as composite measure of highest education level attained at age 37, median household income and occupation. Results: In mediation analyses, adjusted for age, race and sex pathways were noted in that lower child SES was associated with CAs and CAs were associated with lower adult SES. Furthermore, CAs partially mediated the relation between childhood SES and adult SES. The proportion mediated by CA was small and only noted among African-American (4%) and White participants (5%). Conclusions: Childhood SES is associated with CAs. In turn, CAs are associated with lower adult SES, independent of childhood SES supporting the notion that intervening on CAs early on in the lifecourse could influence health and wellbeing throughout the life course.

Low-coverage sequencing cost-effectively detects known and novel variation in underrepresented populations.

Genetic studies in underrepresented populations identify disproportionate numbers of novel associations. However, most genetic studies use genotyping arrays and sequenced reference panels that best capture variation most common in European ancestry populations. To compare data generation strategies best suited for underrepresented populations, we sequenced the whole genomes of 91 individuals to high coverage as part of the Neuropsychiatric Genetics of African Population-Psychosis (NeuroGAP-Psychosis) study with participants from Ethiopia, Kenya, South Africa, and Uganda. We used a downsampling approach to evaluate the quality of two cost-effective data generation strategies, GWAS arrays versus low-coverage sequencing, by calculating the concordance of imputed variants from these technologies with those from deep whole-genome sequencing data. We show that low-coverage sequencing at a depth of ≥4× captures variants of all frequencies more accurately than all commonly used GWAS arrays investigated and at a comparable cost. Lower depths of sequencing (0.5-1×) performed comparably to commonly used low-density GWAS arrays. Low-coverage sequencing is also sensitive to novel variation; 4× sequencing detects 45% of singletons and 95% of common variants identified in high-coverage African whole genomes. Low-coverage sequencing approaches surmount the problems induced by the ascertainment of common genotyping arrays, effectively identify novel variation particularly in underrepresented populations, and present opportunities to enhance variant discovery at a cost similar to traditional approaches.

Association of Economic Status and Educational Attainment With Posttraumatic Stress Disorder: A Mendelian Randomization Study.

Importance: There is a well-established negative association of educational attainment (EA) and other traits related to cognitive ability with posttraumatic stress disorder (PTSD), but the underlying mechanisms are poorly understood. Objectives: To investigate the association of PTSD with traits related to EA. Design, Setting, and Participants: Genetic correlation, polygenic risk scoring, and mendelian randomization (MR) were conducted including 23 185 individuals with PTSD and 151 309 control participants from the Psychiatric Genomics Consortium for PTSD and up to 1 131 881 individuals assessed for EA and related traits from UK Biobank, 23andMe, and the Social Science Genetic Association Consortium. Data were analyzed from July 3 through November 19, 2018. Main Outcomes and Measures: Genetic correlation obtained from linkage disequilibrium score regression, phenotypic variance explained by polygenic risk scores, and association estimates from MR. Results: Summary association data from multiple genome-wide association studies were available for a total of 1 180 352 participants (634 391 [53.7%] women). Posttraumatic stress disorder showed negative genetic correlations with EA (rg = -0.26; SE = 0.05; P = 4.60 × 10-8). Mendelian randomization analysis, conducting considering a random-effects inverse-variance weighted method, indicated that EA has a negative association with PTSD (ß = -0.23; 95% CI, -0.07 to -0.39; P = .004). Investigating potential mediators of the EA-PTSD association, propensity for trauma exposure and risk-taking behaviors were observed as risk factors for PTSD independent of EA (trauma exposure: ß = 0.37; 95% CI, 0.19 to 0.52; P = 2.57 × 10-5; risk-taking: ß = 0.76; 95% CI, 0.38 to 1.13; P = 1.13 × 10-4), while income may mediate the association of EA with PSTD (MR income: ß = -0.18; 95% CI, -0.29 to -0.07; P = .001; MR EA: ß = -0.23; 95% CI, -0.39 to -0.07; P = .004; multivariable MR income: ß = -0.32; 95% CI, -0.57 to 0.07; P = .02; multivariable MR EA: ß = -0.04; 95% CI, -0.29 to 0.21; SE, 0.13; P = .79). Conclusions and Relevance: Large-scale genomic data sets add further evidence to the negative association of EA with PTSD, also supporting the role of economic status as a mediator in the association observed.

Assessment of Bidirectional Relationships Between Physical Activity and Depression Among Adults: A 2-Sample Mendelian Randomization Study.

Importance: Increasing evidence shows that physical activity is associated with reduced risk for depression, pointing to a potential modifiable target for prevention. However, the causality and direction of this association are not clear; physical activity may protect against depression, and/or depression may result in decreased physical activity. Objective: To examine bidirectional relationships between physical activity and depression using a genetically informed method for assessing potential causal inference. Design, Setting, and Participants: This 2-sample mendelian randomization (MR) used independent top genetic variants associated with 2 physical activity phenotypes-self-reported (n = 377 234) and objective accelerometer-based (n = 91 084)-and with major depressive disorder (MDD) (n = 143 265) as genetic instruments from the largest available, nonoverlapping genome-wide association studies (GWAS). GWAS were previously conducted in diverse observational cohorts, including the UK Biobank (for physical activity) and participating studies in the Psychiatric Genomics Consortium (for MDD) among adults of European ancestry. Mendelian randomization estimates from each genetic instrument were combined using inverse variance weighted meta-analysis, with alternate methods (eg, weighted median, MR Egger, MR-Pleiotropy Residual Sum and Outlier [PRESSO]) and multiple sensitivity analyses to assess horizontal pleiotropy and remove outliers. Data were analyzed from May 10 through July 31, 2018. Main Outcomes and Measures: MDD and physical activity. Results: GWAS summary data were available for a combined sample size of 611 583 adult participants. Mendelian randomization evidence suggested a protective relationship between accelerometer-based activity and MDD (odds ratio [OR], 0.74 for MDD per 1-SD increase in mean acceleration; 95% CI, 0.59-0.92; P = .006). In contrast, there was no statistically significant relationship between MDD and accelerometer-based activity (ß = -0.08 in mean acceleration per MDD vs control status; 95% CI, -0.47 to 0.32; P = .70). Furthermore, there was no significant relationship between self-reported activity and MDD (OR, 1.28 for MDD per 1-SD increase in metabolic-equivalent minutes of reported moderate-to-vigorous activity; 95% CI, 0.57-3.37; P = .48), or between MDD and self-reported activity (ß = 0.02 per MDD in standardized metabolic-equivalent minutes of reported moderate-to-vigorous activity per MDD vs control status; 95% CI, -0.008 to 0.05; P = .15). Conclusions and Relevance: Using genetic instruments identified from large-scale GWAS, robust evidence supports a protective relationship between objectively assessed-but not self-reported-physical activity and the risk for MDD. Findings point to the importance of objective measurement of physical activity in epidemiologic studies of mental health and support the hypothesis that enhancing physical activity may be an effective prevention strategy for depression.

Street Audits to Measure Neighborhood Disorder: Virtual or In-Person?

Neighborhood conditions may influence a broad range of health indicators, including obesity, injury, and psychopathology. In particular, neighborhood physical disorder-a measure of urban deterioration-is thought to encourage crime and high-risk behaviors, leading to poor mental and physical health. In studies to assess neighborhood physical disorder, investigators typically rely on time-consuming and expensive in-person systematic neighborhood audits. We compared 2 audit-based measures of neighborhood physical disorder in the city of Detroit, Michigan: One used Google Street View imagery from 2009 and the other used an in-person survey conducted in 2008. Each measure used spatial interpolation to estimate disorder at unobserved locations. In total, the virtual audit required approximately 3% of the time required by the in-person audit. However, the final physical disorder measures were significantly positively correlated at census block centroids (r = 0.52), identified the same regions as highly disordered, and displayed comparable leave-one-out cross-validation accuracy. The measures resulted in very similar convergent validity characteristics (correlation coefficients within 0.03 of each other). The virtual audit-based physical disorder measure could substitute for the in-person one with little to no loss of precision. Virtual audits appear to be a viable and much less expensive alternative to in-person audits for assessing neighborhood conditions.

Impact of persistent and adolescent-limited antisocial behaviour on adult health outcomes.

BACKGROUND: Persistent engagement in antisocial behaviour across developmental periods is thought to increase the risk for early disease morbidity. However, less is known about potential adverse health outcomes among the much larger subset of individuals with antisocial behaviour limited to adolescence. METHODS: Using data from the Providence, Rhode Island cohort of the Collaborative Perinatal Project, we examined the association between developmentally based subtypes of antisocial behaviour and health outcomes (n=801). Official arrest records and self-reports of engagement in antisocial behaviour were used to classify participants into antisocial groups (persistent into adulthood, adolescent-limited, no significant problems) that were contrasted across important adult health indicators. RESULTS: With few exceptions, those with persistent antisocial behaviour had the highest prevalence of each health problem. Compared to those with no antisocial behaviour, participants with persistent problems had poorer overall health and significantly elevated odds of cardiovascular problems, wheezing, lower back pain, cancer, serious injury and emergency department visits. Those with adolescent-limited behaviour experienced significantly increased odds of health concerns including poorer overall health, hypercholesterolaemia, acute respiratory problems and wheezing, lower back pain and emergency department visits compared to participants with no antisocial behaviour. Both antisocial groups reported barriers to healthcare access. CONCLUSIONS: Findings highlight the impact of persistent antisocial behaviour on adult health, and suggest that antisocial behaviour limited to adolescence is also an important marker of poor health. Given that antisocial behaviour during adolescence is an important early marker of adverse health outcomes, youth exhibiting serious behavioural problems should be targeted for preventive interventions.

Unit support protects against sexual harassment and assault among national guard soldiers.

OBJECTIVE: Despite concerns about increased sexual harassment and assault after the 2013 legislation repealing the ban on women in combat, little research has examined military factors that could prevent sexual harassment and assault during deployment. This study examined whether unit support, which reflects the quality of service members' relationships within their unit, protects against sexual harassment and assault during deployment. METHODS: Participants were 1,674 Ohio Army National Guard service members who reported at least one deployment during a telephone survey conducted in 2008 and 2009. Participants completed measures of sexual harassment/assault, unit support, and psychosocial support. Logistic regression was used to model odds of sexual harassment/assault. RESULTS: Approximately 13.2% of men (n = 198) and 43.5% of women (n = 74) reported sexual harassment, and 1.1% of men (n = 17) and 18.8% of women (n = 32) reported sexual assault during their most recent deployment. Greater unit support was associated with decreased odds of sexual harassment and assault. CONCLUSIONS: A substantial proportion of men and women reported sexual harassment/assault. Greater unit support was associated with diminished odds of sexual harassment/assault during deployment. Programming designed to improve unit cohesion has the potential to reduce sexual harassment and assault.

The burden of loss: unexpected death of a loved one and psychiatric disorders across the life course in a national study.

OBJECTIVE: Unexpected death of a loved one is common and associated with subsequent elevations in symptoms of multiple forms of psychopathology. Determining whether this experience predicts novel onset of psychiatric disorders and whether these associations vary across the life course has important clinical implications. The authors examined associations of a loved one's unexpected death with first onset of common anxiety, mood, and substance use disorders in a population-based sample. METHOD: The relation between unexpected death of a loved one and first onset of lifetime DSM-IV disorders was estimated by using a structured interview of adults in the U.S. general population (analytic sample size=27,534). Models controlled for prior occurrence of any disorder, other traumatic experiences, and demographic variables. RESULTS: Unexpected death of a loved one was the most common traumatic experience and most likely to be rated as the respondent's worst, regardless of other traumatic experiences. Increased incidence after unexpected death was observed at nearly every point across the life course for major depressive episode, panic disorder, and posttraumatic stress disorder. Increased incidence was clustered in later adult age groups for manic episode, phobias, alcohol use disorders, and generalized anxiety disorder. CONCLUSIONS: The bereavement period is associated with elevated risk for the onset of multiple psychiatric disorders, consistently across the life course and coincident with the experience of the loved one's death. Novel associations between unexpected death and onset of several disorders, including mania, confirm multiple case reports and results of small studies and suggest an important emerging area for clinical research and practice.

Trajectories of posttraumatic stress among urban residents.

Urban residents experience a wide range of traumatic events and are at increased risk of assaultive violence. Although previous research has examined trajectories of posttraumatic stress (PTS) through latent class growth analysis (LCGA) among persons exposed to the same index events (e.g., a natural disaster), PTS trajectories have not been documented among urban residents. The aims of this study were to conduct LGCA with a sample of trauma survivors from Detroit, Michigan (N = 981), and to explore predictors of trajectory membership. Participants completed three annual telephone surveys, each of which included the posttraumatic stress disorder (PTSD) Checklist-Civilian Version. Four PTS trajectories were detected. Although the majority evidenced a trajectory of consistently few symptoms (Low: 72.5%), 4.6% were in a trajectory of chronic severe PTSD (High), and the remainder were in trajectories of consistently elevated, but generally subclinical, levels of PTS (Decreasing: 12.3%; Increasing: 10.6%). Socioeconomic disadvantage (e.g., lower income), more extensive trauma history (e.g., childhood abuse), and fewer social resources (e.g., lower social support) were associated with membership in higher PTS trajectories, relative to the Low trajectory. The results suggest that efforts to reduce PTS in urban areas need to attend to socioeconomic vulnerabilities in addition to trauma history and risk for ongoing trauma exposure.

The need for trauma-sensitive language use in literacy and health literacy screening instruments.

The authors recently began a research study, funded by the National Institute of Mental Health, aimed at increasing the understanding of the ways in which limited literacy affects the lives of people with serious mental illness. In preparing for the study, the authors reviewed many health literacy screens and assessments for their appropriateness in public urban mental health settings. The Rapid Estimate of Adult Literacy in Medicine and the Test of Functional Health Literacy in Adults, perhaps the most frequently used assessments of health literacy, involve assessments that include lists of words that the test-taker must choose from or read. Each of these instruments includes language that is potentially triggering for trauma survivors, particularly those with posttraumatic stress disorder (PTSD). The research participants for the current project are consumers of mental health services, and thus, the authors believe it is essential to remove the problematic language, given that the likelihood of a diagnosis of PTSD and/or a history of abuse is higher than average among this population. However, the authors argue that this issue applies to anyone who administers these instruments, because sexual assault and abuse, as well as PTSD diagnoses, are certainly not confined to those who seek mental health services. The authors' aim is not only to call attention to the use of triggering language in existing literacy and health-related assessments and research instruments, but also to advocate that others take similar steps toward embracing more sensitive language by removing or replacing words that may cause unnecessary stress, anxiety, or pain to those who are at increased risk of retraumatization.

Epigenetic signatures may explain the relationship between socioeconomic position and risk of mental illness: preliminary findings from an urban community-based sample.

Low socioeconomic position (SEP) has previously been linked to a number of negative health indicators, including poor mental health. The biologic mechanisms linking SEP and mental health remain poorly understood. Recent work suggests that social exposures influence DNA methylation in a manner salient to mental health. We conducted a pilot investigation to assess whether SEP, measured as educational attainment, modifies the association between genomic methylation profiles and traumatic stress in a trauma-exposed sample. Results show that methylation × SEP interactions occur preferentially in genes pertaining to nervous system function, suggesting a plausible biological pathway by which SEP may enhance sensitivity to stress and, in turn, risk of posttraumatic stress disorder.[Supplementary materials are available for this article. Go to the publisher's online edition of Biodemography and Social Biology for the following free supplemental resource: Supplementary tables of full model and functional annotation clustering results.].

Childhood adversity and cell-mediated immunity in young adulthood: does type and timing matter?

Childhood adversity can have powerful effects on health over the life course. Persistent changes in cell-mediated immune function may be one pathway linking adverse childhood experiences with later disease risk. However, limited research has examined childhood adversity in relation to cell-mediated immune function, and in particular, immune response to latent viruses in adulthood. The present study investigated the association of two types of childhood adversity, socioeconomic disadvantage during adolescence and abuse prior to age 18, with Epstein-Barr Virus (EBV) antibody titers in a large nationally representative sample of young adults aged 24-32years. Data were drawn from the National Longitudinal Study on Adolescent Health, Wave 4 (n=13,162). We examined the associations of three indicators of adolescent SES (parental education, household income, and occupational status) and frequency and timing of physical and sexual abuse with EBV antibodies, controlling for age, sex, race/ethnicity, and presence of a smoker in the household during adolescence. Lower parental occupational status and some categories of lower education were associated with elevated EBV antibodies (p<.05), and individuals who reported sexual abuse that occurred more than 10times had elevated EBV antibodies relative to individuals who were not sexually abused (p=0.03). Among individuals exposed to physical abuse, those who were first abused at age 3-5years had heightened EBV antibodies relative to those first abused during adolescence (p=0.004). This study extends prior research linking early adversity and immune function, and provides initial evidence that childhood adversity has a persistent influence on immune responses to latent infection in adulthood.

Heterogeneity of posttraumatic stress symptoms in a highly traumatized low income, urban, African American sample.

Trauma is associated with a range of outcomes; identification of homogeneous profiles of posttrauma symptoms may inform theory, diagnostic refinement, and intervention. The present investigation applies a novel analytic technique to the identification of homogeneous subgroups of post-traumatic symptomatology in a large sample of African American adults reporting high levels of trauma. Latent profiles of posttraumatic stress disorder (PTSD) symptom severity were tested using latent profile analysis. Pseudo-class draws were used to characterize class differences across types of trauma, diagnostic comorbidities, and clinically-relevant features. Participants consisted of 2915 highly traumatized African Americans living in low income, urban setting and recruited from medical clinics in Atlanta, GA. Findings supported the presence of six distinct subgroups of posttraumatic stress symptom profiles described as resilient, moderate with amnesia, moderate with diminished interest, moderate without diminished interest and amnesia severe without amnesia, and severe overall. Observed subgroups differed across numerous historical and concurrent factors including childhood trauma, current and lifetime diagnoses of PTSD and major depression, lifetime substance use diagnosis, dissociation, depressive symptoms, emotional dysregulation, negative and positive affect, and history of hospitalization and suicidality. Posttraumatic stress disorder as currently defined is comprised of homogeneous subgroups with important differences in posttraumatic stress symptom endorsement as well as concomitant differentiation of associated diagnoses and clinically-relevant associated features.

The association between childhood emotional functioning and adulthood inflammation is modified by early-life socioeconomic status.

OBJECTIVE: Identifying interrelationships among childhood social disadvantage, emotional functioning and adult health may help illustrate how health disparities may become embedded early in life, yet few have considered how these factors are associated. We examined whether the association of child emotional functioning and adult health risk was modified by child socioeconomic status (CSES), or whether child emotional functioning mediated the association of CSES and adult health risk. METHOD: We studied 430 adult offspring (mean age 42 years) of Collaborative Perinatal Project participants, a cohort of pregnant women enrolled in 1959-1966 (Broman, Nichols, & Kennedy, 1975; Niswander & Gordon, 1972). Child emotional functioning was assessed by psychologist ratings at age 7 and included inappropriate self regulation (ISR) and distress proneness. CSES measures included parental education, household income, and parental occupation. Adult health risk was measured by the inflammatory marker C-reactive protein (CRP). Hypotheses were tested with multiple linear regression. Effect modification was evaluated via interaction terms and stratification of fully adjusted models by CSES. Mediation by child emotional functioning was evaluated via coefficient changes. RESULTS: There was no evidence that child emotional functioning mediated the association of CSES and CRP. Significant interactions were observed for ISR and low income (b = 1.67, SE = 0.70, p < .05), and distress proneness and low (b = 3.14, SE = 1.47, p < .05) and middle (b = 3.52, SE = 1.46, p < .05) income. Stratified models indicated that associations of child emotion with CRP varied significantly by level of parental education, household income and occupation. CONCLUSION: The highest levels of adult inflammation were observed among those with childhood emotional problems who were also exposed to low socioeconomic status as children. This study suggests adulthood disparities in CRP may have developmental origins in childhood adversity.

State-level women's status and psychiatric disorders among US women.

PURPOSE: Although greater gender equality at the state-level is associated with fewer depressive symptoms in women after controlling for individual-level confounders, the extent to which state-level women's status is related to psychiatric disorders in women and gender differences in psychopathology has never been examined. We examined these associations in the current report. METHODS: We used data from the National Epidemiologic Survey on Alcohol and Related Conditions (n=34,653), a national probability sample of US adults. Respondents completed structured diagnostic assessments of DSM-IV psychiatric disorders. We used generalized estimating equations to examine associations between four state-level indicators of women's status (political participation, employment/earnings, social/economic autonomy, and reproductive rights) and odds of 12-month mood and anxiety disorders among women. We also tested whether women's status predicted the magnitude of gender differences in psychiatric disorders. RESULTS: State-level political participation, employment/earnings, and social/economic autonomy were unrelated to odds of 12-month mood and anxiety disorders among women. However, the prevalence of major depression and post-traumatic stress disorder was lower in states where women have greater reproductive rights (OR 0.93-0.95), controlling for individual-level risk factors. None of the women's status indicators predicted gender differences in mood and anxiety disorder prevalence. CONCLUSIONS: State-level women's status was largely unrelated to mood and anxiety disorders in women or to gender differences in these disorders. Investigation of social factors that play a role in shaping the distribution of individual-level risk factors that are associated with gender disparities in psychiatric disorders represents an important avenue for future research.

Incorporating home demands into models of job strain: findings from the work, family, and health network.

OBJECTIVE: The purpose of this article was to integrate home demands with the demand-control-support model to test if home demands interact with job strain to increase depressive symptoms. METHODS: Data were from 431 employees in four extended care facilities. Presence of a child younger than 18 years in the household signified home demands. The outcome was depressive symptoms based on a shortened version of the Center for Epidemiologic Studies Depression Scale. RESULTS: The association between job strain and depressive symptoms was moderated by social support (SS) and presence of a child in the household (child). There was no association among participants with high SS and no child, but a positive one among participants with low SS and a child. CONCLUSIONS: Job strain may be a particularly important determinant of depressive symptoms among employees with family demands. Models of job strain should expand to incorporate family demands.

Gene-environment interaction in posttraumatic stress disorder: review, strategy and new directions for future research.

The purpose of this article is to encourage research investigating the role of measured gene-environment interaction (G x E) in the etiology of posttraumatic stress disorder (PTSD). PTSD is uniquely suited to the study of G x E as the diagnosis requires exposure to a potentially-traumatic life event. PTSD is also moderately heritable; however, the role of genetic factors in PTSD etiology has been largely neglected both by trauma researchers and psychiatric geneticists. First, we summarize evidence for genetic influences on PTSD from family, twin, and molecular genetic studies. Second, we discuss the key challenges in G x E studies of PTSD and offer practical strategies for addressing these challenges and for discovering replicable G x E for PTSD. Finally, we propose some promising new directions for PTSD G x E research. We suggest that G x E research in PTSD is essential to understanding vulnerability and resilience following exposure to a traumatic event.