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

Extended Swedish Adoption Study of Adverse Stress Responses and Posttraumatic Stress Disorder

Importance

Twin studies have found that posttraumatic stress disorder (PTSD) is influenced by both genetic and environmental factors within a generation. No study has used an adoption design, which can address questions about the degree and sources of cross-generational transmission of adverse stress responses (ASRs) and PTSD.

Objectives

To examine whether ASRs or PTSD are transmitted from parents to offspring, and to clarify the relative importance of genes and rearing.

Design, Setting, and Participants

This cohort study used nationwide Swedish registry data from parents and offspring (n = 2 194 171, born 1960-1992) of 6 types of families (intact; had not lived with biological father; had not lived with biological mother; lived with stepfather; lived with stepmother; and adoptive). Follow-up occurred on December 31, 2018, and data were analyzed from March 3, 2023, to January 16, 2024.

Exposures

Three sources of parent-offspring resemblance: genes plus rearing, genes only, and rearing only.

Main Outcomes and Measures

Diagnoses of ASRs or PTSD were obtained from national inpatient, outpatient, and primary care medical registries. Parent-child resemblance was assessed by tetrachoric correlation. Sensitivity analyses were conducted to control for possible shared traumatic events.

Results

The study population included 2 194 171 individuals of 6 family types (1 146 703 [52.3%] male; median [range] age, 42 [20-63] years). The weighted tetrachoric correlations across family types were 0.15 (95% CI, 0.15-0.16) for genes plus rearing, 0.08 (95% CI, 0.06-0.11) for genes only, and 0.10 (95% CI, 0.07-0.12) for rearing only. Controlling for potential shared traumatic events, sensitivity analyses found that the correlation for rearing decreased, with the most conservative control (exclusion of parent-offspring dyads with onset of ASRs or PTSD within 1 year) suggesting equal correlations with genes and rearing.

Conclusions and Relevance

Diagnosis of ASRs or PTSD demonstrated cross-generational transmission, including both genetic and rearing correlations. Sensitivity analyses suggested that shared traumatic events partially accounted for the observed rearing correlations.

The Psychedelic Future of Post-Traumatic Stress Disorder Treatment

Post-traumatic stress disorder (PTSD) is a mental health condition that can occur following exposure to a traumatic experience. An estimated 12 million U.S. adults are presently affected by this disorder. Current treatments include psychological therapies (e.g., exposure-based interventions) and pharmacological treatments (e.g., selective serotonin reuptake inhibitors (SSRIs)). However, a significant proportion of patients receiving standard-of-care therapies for PTSD remain symptomatic, and new approaches for this and other trauma-related mental health conditions are greatly needed. Psychedelic compounds that alter cognition, perception, and mood are currently being examined for their efficacy in treating PTSD despite their current status as Drug Enforcement Administration (DEA)- scheduled substances. Initial clinical trials have demonstrated the potential value of psychedelicassisted therapy to treat PTSD and other psychiatric disorders. In this comprehensive review, we summarize the state of the science of PTSD clinical care, including current treatments and their shortcomings. We review clinical studies of psychedelic interventions to treat PTSD, trauma-related disorders, and common comorbidities. The classic psychedelics psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) and DMT-containing ayahuasca, as well as the entactogen 3,4-methylenedioxymethamphetamine (MDMA) and the dissociative anesthetic ketamine, are reviewed. For each drug, we present the history of use, psychological and somatic effects, pharmacology, and safety profile. The rationale and proposed mechanisms for use in treating PTSD and traumarelated disorders are discussed. This review concludes with an in-depth consideration of future directions for the psychiatric applications of psychedelics to maximize therapeutic benefit and minimize risk in individuals and communities impacted by trauma-related conditions.

Suicidality in civilian women with PTSD: Possible link to childhood maltreatment, proinflammatory molecules, and their genetic variations

Background

Posttraumatic stress disorder (PTSD) is a robust risk factor for suicide. Studies have suggested an association between suicide and elevated inflammatory markers, although such evidence in PTSD is scarce. Suicide risk, PTSD, and inflammatory molecules are all shown to be associated with childhood maltreatment and genetic factors.

Methods

We examined the association between suicidal ideation/risk and inflammatory markers in 83 civilian women with PTSD, and explored the possible influence of childhood maltreatment and inflammatory genes. Suicidal ideation and risk were assessed using the Beck Depression Inventory-II and the Mini-International Neuropsychiatric Interview. Childhood maltreatment history was assessed with the Childhood Trauma Questionnaire (CTQ). Blood levels of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and high-sensitivity tumor necrosis factor-α were measured. Genetic polymorphisms of CRP rs2794520 and IL6 rs1800796 were genotyped.

Results

Suicidal ideation was significantly positively correlated with hsCRP (p = 0.002) and IL-6 (p = 0.015) levels. Suicide risk weighted score was significantly positively correlated with hsCRP (p = 0.016) levels. The risk alleles of CRP rs2794520 and IL6 rs1800796 leading to increased respective protein levels were dose-dependently associated with higher risk of suicide (p = 0.007 and p = 0.029, respectively). The CTQ total score was significantly correlated with suicidal ideation and risk, but not with inflammatory marker levels. Furthermore, a multivariate regression analysis controlling for PTSD severity and potential confounders revealed that rs2794520 and rs1800796, but not hsCRP or IL-6 levels, significantly predicted suicidal ideation (p < 0.001) and risk (p = 0.007), respectively.

Conclusion

Genetic variations within inflammatory genes might be useful in detecting PTSD patients at high risk of suicide.

The Relationship among Anxiety, Worry, Perceived Stress, Defense Mechanisms, and High Levels of Post-Traumatic Stress Symptoms: A Discriminant Analytic Approach

Post-traumatic stress disorder (PTSD) is a pathological condition that may lead to a significant deterioration in the quality of life over time. Therefore, the study of the elements that can characterize the disorder could be considered of great clinical interest and relevance. The aim of the present research was to empirically discriminate the influence of perceived stress, state anxiety, worry, and defense mechanisms (mature, neurotic, and immature) at different levels of post-traumatic stress symptoms. A sample of 1250 participants (69.5% women, 30.5% men; M_age = 34.52, SD = 11.857) completed an online survey including the Impact of Event Scale-Revised, Ten-Item Perceived Stress Scale, Penn State Worry Questionnaire, Forty Item Defense Style Questionnaire, and State-Trait Anxiety Inventory-Form X3. Data were analysed by implementing MANOVA and discriminant analysis. Results showed significant differences in the levels of perceived stress, state anxiety, and worry, as well as neurotic and immature defenses based on the levels of post-traumatic stress symptoms: F(12,2484) = 85.682, p < 0.001; Wilk's Λ = 0.430. Furthermore, these variables discriminate significant accuracy between participants who reported a mild psychological impact and those with a probable presence of PTSD, with perceived stress, which was found to be the best predictor. Classification results indicated that the original grouped cases were classified with 86.3% overall accuracy. Such findings may provide useful insight for clinical practice.

Traumatic experiences of the Great East Japan Earthquake and postpartum depressive symptoms: The Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

BACKGROUND

Natural disasters can have serious mental health consequences. We aimed to examine the long-term effects of the 2011 Great East Japan Earthquake (GEJE) on postpartum depressive symptoms (PDS).

METHODS

The Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study recruited pregnant women in Miyagi Prefecture from 2013 to 2016. Data from 11,403 participants were used in this study. Women were asked about their traumatic experiences of the GEJE with questions addressing threat, witness, and loss. PDS were defined as Edinburgh Postnatal Depression Scale score ≥9 at 1 month after delivery. Multiple logistic regression analyses were conducted to examine the associations of different traumatic experiences of the GEJE and number of traumatic experiences with PDS, after adjustment for age, parity, feelings toward pregnancy, education, income, social isolation, house damage caused by the GEJE, and survey year.

RESULTS

About two-fifths of women had at least one traumatic experience of the GEJE. The prevalence of PDS at 1 month after delivery was 13.3 %. Life-threatening experience and witnessing another person's actual or threatened death were associated with PDS: the odds ratios (ORs) were 1.40 (95 % confidence interval [CI], 1.24-1.59) and 1.28 (95 % CI, 1.08-1.53), respectively. Loss of close person was not associated with PDS: the OR was 1.13 (95 % CI, 0.99-1.30). Larger number of traumatic experiences of the GEJE was associated with increased risk of PDS (p for trend <0.001).

LIMITATIONS

PDS was self-reported.

CONCLUSIONS

Traumatic experiences of the GEJE prior to pregnancy were associated with increased risks of PDS.

A Systematic Review of the Biological Correlates and Consequences of Childhood Maltreatment and Adverse Childhood Experiences

Childhood maltreatment (CM) and adverse childhood experiences (ACEs) are two primary forms of interpersonal victimization that have been associated with a host of deleterious health outcomes. Studies over the past decade have begun to use a range of biologically informed methods to better understand the role biology plays in the relationship between CM, ACEs, and later life outcomes. This line of research has shown that both forms of victimization occur at sensitive periods of development, which can increase the likelihood of "getting under the skin" and influence health and behavior across the life course. This review examines the current state of knowledge on this hypothesis. One hundred and ninety-nine studies are included in this systematic review based on criteria that they be written in English, use a biologically informed method, and be conducted on samples of humans. Results reveal that latent additive genetic influences, biological system functioning captured by biomarkers, polygenic risk scores, and neurobiological factors are commonly associated with exposure and response to CM and ACEs. The implication of these findings for the existing body of research on early life victimization and recommendations for future research and policy are discussed.

Laboratory models of post-traumatic stress disorder: The elusive bridge to translation

Post-traumatic stress disorder (PTSD) is a debilitating mental illness composed of a heterogeneous collection of symptom clusters. The unique nature of PTSD as arising from a precipitating traumatic event helps simplify cross-species translational research modeling the neurobehavioral effects of stress and fear. However, the neurobiological progress on these complex neural circuits informed by animal models has yet to produce novel, evidence-based clinical treatment for PTSD. Here, we provide a comprehensive overview of popular laboratory models of PTSD and provide concrete ideas for improving the validity and clinical translational value of basic research efforts in humans. We detail modifications to simplified animal paradigms to account for myriad cognitive factors affected in PTSD, which may contribute to abnormalities in regulating fear. We further describe new avenues for integrating different areas of psychological research underserved by animal models of PTSD. This includes incorporating emerging trends in the cognitive neuroscience of episodic memory, emotion regulation, social-emotional processes, and PTSD subtyping to provide a more comprehensive recapitulation of the human experience to trauma in laboratory research.

The Association between COMT Val158Met Polymorphism and the Post-Traumatic Stress Disorder Risk: A Meta-Analysis

BACKGROUND

Genetic factors were suggested to have influence on the development of post-traumatic stress disorder (PTSD). The possible association between catechol-O-methyltransferase (COMT) Val158Met polymorphism and PTSD has been evaluated in several studies. But the results were still controversial. Therefore, we conduct this meta-analysis to address these issues.

METHODS

The PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched for eligible studies. The pooled odds ratio (OR) with 95% confidence interval (CI) was calculated to estimate the association between COMT Val158Met polymorphism and PTSD.

RESULTS

Five articles including 6 studies with 893 cases and 968 controls were finally included in the present meta-analysis. The pooled analyses did not demonstrate a significant association between the COMT Val158Met polymorphism and PTSD in any of the selected genetic models: allele model (OR = 1.13, 95% CI: 0.97-1.31), dominant model (OR = 1.17, 95% CI: 0.93-1.46), recessive model (OR = 1.44, 95% CI: 0.78-2.66), and additive model (OR = 1.54, 95% CI: 0.85-2.80). Subgroup analyses suggested that the Hardy-Weinberg equilibrium status of genotype distributions could influence the relationship of COMT Val158Met polymorphism and PTSD.

CONCLUSIONS

The present meta-analysis suggested that the COMT Val158Met polymorphism may not be associated with the PTSD risk. Further large-scale and population-representative studies are warranted to evaluate the impact of the COMT Val158Met polymorphism on the risk of PTSD.

Hypothalamic-pituitary-adrenal axis and renin-angiotensin-aldosterone system in adulthood PTSD and childhood maltreatment history

Accumulated evidence shows that psychological trauma and posttraumatic stress disorder (PTSD) are associated with dysfunction in the hypothalamic-pituitary-adrenal (HPA) axis. Besides the HPA axis hormones, recent evidence suggests that the renin-angiotensin-aldosterone (RAA) system and genetic factors may be involved in trauma/PTSD as well as in HPA axis regulation. This study attempted to better understand the HPA axis function in relation to PTSD and childhood maltreatment by simultaneously examining RAA system and genetic polymorphisms of candidate genes. Here we studied 69 civilian women with PTSD and 107 healthy control women without DSM-IV-based traumatic experience. Childhood maltreatment history was assessed with the Childhood Trauma Questionnaire. PTSD severity was assessed with the Posttraumatic Diagnostic Scale. Functional disability was assessed with the Sheehan Disability Scale. HPA axis was examined by measuring blood levels of cortisol, adrenocorticotropic hormone, and dehydroepiandrosterone-sulphate (DHEA-S). RAA system was examined by measuring blood renin and aldosterone levels. The FKBP5 rs1360780 and CACNA1C rs1006737 polymorphisms were genotyped. No significant differences were seen between patients and controls in any of the five hormone levels. DHEA-S levels were significantly negatively correlated with overall PTSD severity (p = 0.003) and functional disability (p = 0.008). A two-way analysis of variance with diagnostic groups and genotypes as fixed factors revealed that patients with the rs1006737 A-allele had significantly lower DHEA-S levels than patients with the GG genotype (p = 0.002) and controls with the A-allele (p = 0.006). Childhood maltreatment history was not significantly correlated with any of the five hormone levels. These results were generally unchanged after controlling for the potentially confounding effect of age, depression, and anxiety. Our findings suggest that lower DHEA-S levels could indicate more severe subtype of PTSD, the association of which might be partly modified by the CACNA1C polymorphism.

Combatting intergenerational effects of psychotrauma with multifamily therapy

There is growing evidence that parental trauma is associated with psychosocial disorders, externalizing and internalizing problems, and higher sensitivity to posttraumatic stress disorder (PTSD) in children. Recent research findings suggest multidimensional relational, psychological, and neurobiological interrelated pathways of intergenerational influence. Moreover, the intergenerational effects of parental trauma need to be understood within a broader systemic context, as a part of family adaptation. This article explores research findings and clinical practice to enhance our understanding of intergenerational processes and presents directions for therapeutic interventions. A trauma-focused multi-family therapy, aiming to restrict the relational consequences of parental trauma and strengthen family resilience, is described. The proposition is that to facilitate and improve the quality of parent-child interaction in response to psychotrauma, fostering emotion regulation capacities and mentalization is crucial. These efforts offered through family group interventions may benefit various families coping with adversity in culturally diverse societies.

Myelination defects in the medial prefrontal cortex of Fkbp5 knockout mice

The hypothalamic-pituitary-adrenal (HPA) axis plays a principal role in stress response regulation and has been implicated in the etiology of stress-related disorders. The HPA axis regulates the normal synthesis and release of glucocorticoids; dysregulation of the HPA axis causes abnormal responses to stress. FK506-binding protein 5 (FKBP5), a co-chaperone of heat shock protein 90 in the glucocorticoid receptor (GR) molecular complex, is a key GR sensitivity regulator. FKBP5 single nucleotide polymorphisms are associated with dysregulated HPA axis and increased risk of stress-related disorders, including posttraumatic stress disorder (PTSD) and depression. In this study, we profiled the microRNAs (miRNAs) in the medial prefrontal cortex of Fkbp5 knockout (Fkbp5^-/- ) mice and identified the target genes of differentially expressed miRNAs using sequence-based miRNA target prediction. Gene ontology analysis revealed that the differentially expressed miRNAs were involved in nervous system development, regulation of cell migration, and intracellular signal transduction. The validation of the expression of predicted target genes using quantitative polymerase chain reaction revealed that the expression of axon development-related genes, specifically actin-binding LIM protein 1 (Ablim1), lemur tyrosine kinase 2 (Lmtk2), kinesin family member 5c (Kif5c), neurofascin (Nfasc), and ephrin type-A receptor 4 (Epha4), was significantly decreased, while that of brain-derived neurotrophic factor (Bdnf) was significantly increased in the brain of Fkbp5^-/- mice. These results suggest that axonal development-related genes can serve as potential targets in future studies focused on understanding the pathophysiology of PTSD.

PTSD is associated with accelerated transcriptional aging in World Trade Center responders

Posttraumatic stress disorder (PTSD) is associated with shortened lifespan and healthspan, which suggests accelerated aging. Emerging evidence suggests that methylation age may be accelerated in PTSD. It is important to examine whether transcriptional age is also accelerated because transcriptome is highly dynamic, associated with age-related outcomes, and may offer greater insight into the premature aging in PTSD. This study is the first reported investigation of the relationship between transcriptional age and PTSD. Using RNA-Seq data from our previous study on 324 World Trade Center responders (201 never had PTSD, 81 with current PTSD, and 42 with past PTSD), as well as a transcriptional age calculator (RNAAgeCalc) recently developed by our group, we found that responders with current PTSD, compared with responders without a PTSD diagnosis, showed accelerated transcriptional aging (p = 0.0077) after adjustment for chronological age and race. We compared our results to the epigenetic aging results computed from several epigenetic clock calculators on matching DNA methylation data. GrimAge methylation age acceleration was also associated with PTSD diagnosis (p = 0.0097), and the results remained significant after adjustment for the proportions of immune cell types. PhenoAge, Hannum, and Horvath methylation age acceleration were not reliably related to PTSD. Both epigenetic and transcriptional aging may provide biological insights into the mechanisms underpinning aging in PTSD.

Mapping the transcriptomics landscape of post-traumatic stress disorder symptom dimensions in World Trade Center responders

Gene expression has provided promising insights into the pathophysiology of post-traumatic stress disorder (PTSD); however, specific regulatory transcriptomic mechanisms remain unknown. The present study addressed this limitation by performing transcriptome-wide RNA-Seq of whole-blood samples from 226 World Trade Center responders. The investigation focused on differential expression (DE) at the gene, isoform, and for the first time, alternative splicing (AS) levels associated with the symptoms of PTSD: total burden, re-experiencing, avoidance, numbing, and hyperarousal subdimensions. These symptoms were associated with 76, 1, 48, 15, and 49 DE genes, respectively (FDR < 0.05). Moreover, they were associated with 103, 11, 0, 43, and 32 AS events. Avoidance differed the most from other dimensions with respect to DE genes and AS events. Gene set enrichment analysis (GSEA) identified pathways involved in inflammatory and metabolic processes, which may have implications in the treatment of PTSD. Overall, the findings shed a novel light on the wide range of transcriptomic alterations associated with PTSD at the gene and AS levels. The results of DE analysis associated with PTSD subdimensions highlights the importance of studying PTSD symptom heterogeneity.

Prevalence of post-traumatic stress symptoms among people influenced by coronavirus disease 2019 outbreak: A meta-analysis

BACKGROUND

As one of the most widely researched consequence of traumatic events, the prevalence of post-traumatic stress symptoms among people exposed to the trauma resulting from coronavirus disease 2019 (COVID-19) outbreak varies greatly across studies. This review aimed at examining the pooled prevalence of post-traumatic stress symptoms among people exposed to the trauma resulting from COVID-19 outbreak.

METHODS

Systematic searches of databases were conducted for literature published on PubMed, EMBASE, Web of Science, the Cochrane Library, PsycArticle, and Chinese National Knowledge Infrastructure until October 14, 2020. Statistical analyses were performed using R software (PROSPERO registration number: CRD42020180309).

RESULTS

A total of 106,713 people exposed to the trauma resulting from the COVID-19 outbreak were identified in the 76 articles, of which 33,810 were reported with post-traumatic stress symptoms. The pooled prevalence of post-traumatic stress symptoms among people exposed to the trauma resulting from COVID-19 outbreak was 28.34%, with a 95% confidence interval of 23.03-34.32%. Subgroup analysis indicated that older age, male and bigger sample size were associated with higher prevalence of post-traumatic stress symptoms. After controlling for other factors, the results of meta-regression showed that the influence of gender and sample size on prevalence is no longer significant.

CONCLUSIONS

Symptoms of post-traumatic stress disorder (PTSD) were very common among people exposed to the trauma resulting from COVID-19 outbreak. Further research is needed to explore more possible risk factors for post-traumatic stress symptoms and identify effective strategies for preventing PTSD-related symptoms among people exposed to the trauma resulting from COVID-19 outbreak.

The "missing heritability"-Problem in psychiatry: Is the interaction of genetics, epigenetics and transposable elements a potential solution?

Psychiatric disorders exhibit an enormous burden on the health care systems worldwide accounting for around one-third of years lost due to disability among adults. Their etiology is largely unknown and diagnostic classification is based on symptomatology and course of illness and not on objective biomarkers. Most psychiatric disorders are moderately to highly heritable. However, it is still unknown what mechanisms may explain the discrepancy between heritability estimates and the present data from genetic analysis. In addition to genetic differences also epigenetic modifications are considered as potentially relevant in the transfer of susceptibility to psychiatric diseases. Though, whether or not epigenetic alterations can be inherited for many generations is highly controversial. In the present article, we will critically summarize both the genetic findings and the results from epigenetic analyses, including also those of noncoding RNAs. We will argue that one possible solution to the "missing heritability" problem in psychiatry is a potential role of retrotransposons, the exploration of which is presently only in its beginnings.

Association of CRP genetic variation with symptomatology, cognitive function, and circulating proinflammatory markers in civilian women with PTSD

BACKGROUND

Posttraumatic stress disorder (PTSD) has been associated with increased inflammation. C-reactive protein (CRP) is a marker of systemic inflammation, and recently, single nucleotide polymorphisms (SNPs) in the CRP gene have been associated with increased blood CRP protein levels and illness severity in PTSD patients. However, the mechanism by which the CRP SNPs are involved in PTSD remains unclear. Here we investigated the association of CRP genetic variation with blood proinflammatory protein levels, symptomatology, and cognitive function, and further explored the moderating effect of childhood maltreatment history, in adult patients with PTSD.

METHODS

Fifty-seven Japanese civilian women with PTSD and 73 healthy control women were enrolled. Three SNPs in the CRP gene, namely rs2794520, rs1130864, and rs3093059, were genotyped, and analyses focused on rs2794520 (T/C). Serum levels of high-sensitivity CRP (hsCRP), high-sensitivity tumor necrosis factor-α (hsTNF-α), and interleukin-6 were measured. PTSD symptoms were evaluated by the Posttraumatic Diagnostic Scale. Cognitive function was assessed by the Repeatable Battery for the Assessment of Neuropsychological Status. Childhood maltreatment history was assessed by the Childhood Trauma Questionnaire.

RESULTS

Patients with the rs2794520 CC/CT genotype, compared to those with the TT genotype, showed significantly higher levels of hsCRP (p=0.009) and hsTNF-α (p=0.001), more severe PTSD symptoms (p=0.036), and poorer cognitive function (p=0.018). A two-way analysis of variance revealed a significant genotype-by-maltreatment interaction for more severe PTSD avoidance symptom (p=0.012).

LIMITATIONS

The relatively small sample size limited our findings.

CONCLUSIONS

These findings may provide an insight into the etiology of PTSD from the inflammatory perspective.

Pharmacotherapeutic considerations for the treatment of posttraumatic stress disorder during and after pregnancy

Introduction: Posttraumatic stress disorder (PTSD) affects 3-4% of the pregnant and postpartum population. Despite its high prevalence, there has been very little research on how the disorder should be managed in this population. This is of importance as untreated PTSD has been associated with adverse outcomes both in pregnancy and in child development.Areas covered: In this article, the authors discuss the existing literature on the pharmacological treatment of PTSD. As guidelines and clinical trials in the treatment of perinatal PTSD are non-existent, they extrapolate the existing data from non-perinatal populations while considering the safety of medications in pregnancy and breastfeeding.Expert opinion: First-line treatment of perinatal PTSD ideally involves evidence-based psychotherapy rather than pharmacotherapy. However, pharmacotherapy may be required in situations of inadequate response, psychiatric co-morbidities, limited access to psychotherapy, or patient preference. The first-line pharmacotherapy options are the antidepressants sertraline, paroxetine, fluoxetine, and venlafaxine. Of these medications, sertraline has the best safety profile in pregnancy and postpartum and is thus the preferred agent. Clinical studies and consensus guidelines in the treatment of perinatal PTSD are needed given the high prevalence of the disorder and the significant risks associated with inadequate treatment.

Sex differences in post-traumatic stress disorder risk: autonomic control and inflammation

AIM

Over 7 million U.S. adults and about 20% of the military population have post-traumatic stress disorder (PTSD), a debilitating condition that is independently linked to a significantly greater risk of developing cardiovascular disease (CVD). Women have twice the probability of developing PTSD after experiencing a traumatic event compared to men. Existing literatures have reported higher inflammation and autonomic dysfunction including impaired baroreflex sensitivity, increased sympathetic reactivity and decreased parasympathetic activity in PTSD. However, most of these findings stem from studies conducted predominantly in males.

METHODS

We attempt in this narrative review to summarize the mixed literature available on sex differences in autonomic dysfunction and inflammation in PTSD, at rest and in response to stress in PTSD.

RESULTS

This review reveals that there is a paucity of research exploring autonomic function in females with PTSD. Recent studies have included female participants without probing for sex differences. A small number of studies have been conducted exclusively in women. Available data suggest that sympathetic nervous system output tends to be heightened, while parasympathetic activity and arterial baroreflex sensitivity appear more blunted in females with PTSD. Although few studies have investigated sex differences in inflammation in PTSD, data within females suggest chronic increases in inflammation with PTSD. This autonomic dysregulation and inflammation have also been described in males with PTSD.

CONCLUSION

In sum, given the inherent biological differences in CVD clinical presentation and characteristics between men and women, human and animal studies aiming at elucidating sex differences in the pathophysiology of PTSD are needed.

Analysis of stress responses in Astyanax larvae reveals heterogeneity among different populations

Stress responses are conserved physiological and behavioral outcomes as a result of facing potentially harmful stimuli, yet in pathological states, stress becomes debilitating. Stress responses vary considerably throughout the animal kingdom, but how these responses are shaped evolutionarily is unknown. The Mexican cavefish has emerged as a powerful system for examining genetic principles underlying behavioral evolution. Here, we demonstrate that cave Astyanax have reduced behavioral and physiological measures of stress when examined at larval stages. We also find increased expression of the glucocorticoid receptor, a repressible element of the neuroendocrine stress pathway. Additionally, we examine stress in three different cave populations, and find that some, but not all, show reduced stress measures. Together, these results reveal a mechanistic system by which cave-dwelling fish reduced stress, presumably to compensate for a predator poor environment.

Modification of the risk of post-traumatic stress disorder (PTSD) by the 5-HTTLPR polymorphisms after Lorca's earthquakes (Murcia, Spain)

Information of the modulation effect of the serotonin transporter gene-linked polymorphic region (5-HTTLPR) on post-traumatic stress disorder (PTSD) after earthquakes is scarce and contradictory. A cross-sectional face-to-face interview survey of a representative sample of the adults was carried out after the Lorca (Spain) earthquakes (May 11, 2011). Socio-demographic variables, DSM-IV diagnostic assessment and earthquake-related stressors were obtained from the Composite International Diagnostic Interview (CIDI). The triallelic and biallelic classification of the 5-HTTLPR polymorphism were genotyped from buccal swabs. Multivariate logistic regression models were used to predict PTSD, including interaction terms to explore gene-environment (G x E) interactions. The vast majority (83%, n = 341) of the Lorca survey respondents (n = 412, 71% response rate) were genotyped. Both classifications of the 5-HTTLPR genotype were in Hardy-Weinberg equilibrium. Prior lifetime PTSD was the only variable that remained a significant predictor after adjustments. There were no significant main effects of earthquake related stressors or 5-HTTLPR. However, G x E interactions of 5-HTTLPR with high emotional impact and prior lifetime anxiety disorders were statistically significant. These results provide new evidence of the modulation effect of the 5-HTTLPR polymorphisms on PTSD risk. This information might characterize people at higher risk of developing PTSD after an earthquake exposure.

Neuroscience and mental state issues in forensic assessment

Neuroscience has already changed how the law understands an individual's cognitive processes, how those processes shape behavior, and how bio-psychosocial history and neurodevelopmental approaches provide information, which is critical to understanding mental states underlying behavior, including criminal behavior. In this paper, we briefly review the state of forensic assessment of mental conditions in the relative culpability of criminal defendants, focused primarily on the weaknesses of current approaches. We then turn to focus on neuroscience approaches and how they have the potential to improve assessment, but with significant risks and limitations.

Parental immigration and offspring post-traumatic stress disorder: A nationwide population-based register study

OBJECTIVES

The aim of this study was to investigate the association between parental immigration status and a diagnosis of post-traumatic stress disorder (PTSD) in their offspring.

METHODS

This nested matched case-control study was based on a Finnish national birth cohort for 1987-2010 and cases were diagnosed with PTSD by 2012 from the Care Register for Health Care. We identified 3639 cases and 14,434 controls individually matched for gender, place and date of birth (±30 days). Conditional logistic regression analyses were conducted to examine the association between parental immigration status, parents' region of birth and time since paternal immigration, and PTSD after controlling for confounding factors.

RESULTS

The likelihood of being diagnosed with PTSD was significantly increased among children with an immigrant father (OR 1.8, 95% CI 1.3 - 2.4) than those with two Finnish parents and one immigrant mother. There was no significant association between having an immigrant mother or two immigrant parents and receiving a diagnosis of PTSD. The likelihood of being diagnosed with PTSD was increased if the children's fathers had migrated less than five years before their birth (OR 1.4, 95% CI 1.03 - 1.9) and if their immigrant fathers had been born in North Africa or the Middle East (OR 2.1, 95% CI 1.4 - 3.3).

LIMITATIONS

The sample included a heterogeneous migrant group without information on the reason for migration. The cases were identified from hospital diagnosis that may have only included severe cases.

CONCLUSION

The increased likelihood of a diagnosis of PTSD underlines the need for psychosocial services among second-generation immigrants.

Orexins and stress

The neuropeptides orexins are important in regulating the neurobiological systems that respond to stressful stimuli. Furthermore, orexins are known to play a role many of the phenotypes associated with stress-related mental illness such as changes in cognition, sleep-wake states, and appetite. Interestingly, orexins are altered in stress-related psychiatric disorders such as Major Depressive Disorder and Anxiety Disorders. Thus, orexins may be a potential target for treatment of these disorders. In this review, we will focus on what is known about the role of orexins in acute and repeated stress, in stress-induced phenotypes relevant to psychiatric illness in preclinical models, and in stress-related psychiatric illness in humans. We will also briefly discuss how orexins may contribute to sex differences in the stress response and subsequent phenotypes relevant to mental health, as many stress-related psychiatric disorders are twice as prevalent in women.

The developing significance of context and function: Neuroscience and law

Neuroscience has already changed the understanding of how intent forms and is acted upon, how an individual's cognitive processes shape behavior, and how bio-psychosocial history and neurodevelopmental approaches provide information that has been largely missing from the assessment of intent. In this paper, we first review the state of forensic assessment of mental condition and intent, focused primarily on the weaknesses of the current approach. In Section 2, we discuss neurobehavioral forensic assessment, which is a neuroscience-based approach. Section 3 focuses on the changing understanding of mental illness and how neuroscience is pushing law towards a functional capacity-and-ability model and away from a diagnostic cut-off model. Finally, in Sections 4 and 5, we turn to the role of social and environmental context in shaping behavior and propose a model of behavioral intent in line with the scientific evidence.

Convergence on reduced stress behavior in the Mexican blind cavefish

Responding appropriately to stress is essential for survival, yet in pathological states, these responses can develop into debilitating conditions such as post-traumatic stress disorder and generalized anxiety. While genetic models have provided insight into the neurochemical and neuroanatomical pathways that underlie stress, little is known about how evolutionary processes and naturally occurring variation contribute to the diverse responses to stressful stimuli observed in the animal kingdom. The Mexican cavefish is a powerful system to address how altered genetic and neuronal systems can give rise to altered behaviors. When introduced into a novel tank, surface fish and cavefish display a stereotypic stress response, characterized by reduced exploratory behavior and increased immobility, akin to "freezing". The stress response in cave and surface forms is reduced by pharmacological treatment with the anxiolytic drug, buspirone, fortifying the notion that behavior in the assay represents a conserved stress state. We find that cave populations display reduced behavioral measures of stress compared to surface conspecifics, including increased time in the top half of the tank and fewer periods of immobility. Further, reduced stress responses are observed in multiple independently derived cavefish populations, suggesting convergence on loss of behavioral stress responses in the novel tank assay. These findings provide evidence of a naturally occurring species with two drastically different forms in which a shift in predator-rich ecology to one with few predators corresponds to a reduction in stress behavior.

Coping strategies of former prisoners of war mediate the intergenerational transmission of posttraumatic stress symptoms

OBJECTIVES

Certain coping strategies, characterized by emotional coping or disengagement/ avoidance, have been linked to posttraumatic stress disorder (PTSD) and PTSD symptoms (PTSS). However, the role of primary trauma victims' coping strategies in the intergenerational transmission of PTSS is still lacking. This prospective study assessed the mediating role of former prisoners of war's (ex-POWs) coping strategies in the associations between ex-POWs' PTSS and their adult offspring's secondary PTSS in relation to their fathers' captivity and psychiatric symptomatology.

DESIGN

A correlational, prospective study.

METHOD

A sample from the 1973 Yom Kippur War composed of 79 Israeli ex-POW father-offspring dyads completed self-report measures. Fathers were assessed in 2001 and 2008, and their adult offspring participated in 2014.

RESULTS

ex-POWs' problem-focused coping strategies of active coping and planning, as well as disengagement-oriented coping strategies of alcohol and substance use and venting of emotions, were negatively associated with offspring's PTSS and psychiatric symptomatology. Importantly, ex-POWs' venting of emotions mediated the link between ex-POWs' PTSS and their offspring's secondary PTSS.

CONCLUSIONS

Ex-POWs with PTSS might expose their offspring to dysregulated mood, behaviors, and cognitions. Special awareness should be given to the venting of emotions coping style as possible mechanism for the intergenerational transmission of captivity-related PTSS.

Applying network analysis to psychological comorbidity and health behavior: Depression, PTSD, and sexual risk in sexual minority men with trauma histories

OBJECTIVE

High rates of depression and posttraumatic stress disorder (PTSD) contribute to sexual risk, particularly in men who have sex with men (MSM) who have experienced childhood sexual abuse. The comorbidity between depression and PTSD and mechanisms by which they contribute to sexual risk in MSM remain unclear. This study sought to demonstrate the feasibility and utility of a network approach to (a) characterize symptom interconnections between depression and PTSD in MSM, (b) identify specific symptoms related to sexual risk behavior, and (c) compare symptom networks across groups at different levels of risk.

METHOD

Cross-sectional baseline data were collected from 296 HIV-negative urban MSM as part of a multisite randomized intervention trial. Symptoms of depression and PTSD were self-reported along with sexual risk behavior. Analyses were performed in R using regularized partial correlation network modeling.

RESULTS

Network analyses revealed complex associations between depression and PTSD symptoms and in relation to sexual risk behavior. While symptoms clustered within their respective disorders, depression and PTSD were connected at key symptom nodes (e.g., sleep, concentration). Specific symptoms (e.g., avoiding thoughts and feelings) were linked to sexual risk behavior. Network comparisons across risk groups suggested avoidant processes could be more readily activated in higher-risk individuals, whereas hyperarousal symptoms may be more salient and protective for lower-risk individuals.

CONCLUSIONS

This study is one of the earliest network analyses of depression and PTSD, and first to extend this inquiry to health behavior. Symptom-level investigations may clarify mechanisms underlying psychological comorbidity and behavioral risk in MSM and refine targets for intervention/prevention. (PsycINFO Database Record

Further evidence for a role of the ADRB2 gene in risk for posttraumatic stress disorder

The aim of the present study was to attempt to replicate the recently reported finding associating rs2400707 of the Adrenoceptor Beta 2, Surface (ADRB2) gene and childhood trauma on PTSD symptoms. Participants included a predominantly veteran cohort of non-Hispanic blacks (NHB; n = 949) and a pre-dominantly veteran cohort of non-Hispanic whites (NHW; n = 759). No main effects were observed for rs2400707 on PTSD diagnosis. Among the NHB participants, we observed an interaction between rs2400707 and history of childhood trauma, whereby with each additional A allele, the odds of having PTSD increased by 1.31, but only among those who had experienced childhood trauma (p = 0.038). The interaction with rs2400707 and childhood trauma was not observed among the NHW study participants (p = 0.892). Taken together, the findings from the present research provide further evidence that the adrenergic system may be an important modulator of PTSD risk; however, additional work is still needed to clarify the exact nature of the relationship between PTSD and rs2400707 of the ADRB2 gene.

PTSD, alcohol dependence, and conduct problems: Distinct pathways via lability and disinhibition

This study tested the role of affect lability and disinhibition in mediating associations between PTSD symptoms and two forms of alcohol-related problems, dependence syndrome symptoms (e.g., impaired control over consumption) and conduct problems (e.g., assault, risk behaviors). Genotype at the serotonin transporter linked polymorphic region (5-HTTLPR) was hypothesized to moderate associations between traumatic stress and PTSD symptoms. In addition, the study tested whether childhood traumatic stress moderated associations between combat trauma and PTSD symptoms. Participants were 270 OIF/OEF/OND veterans. The hypothesized model was largely supported. Participants with the low expression alleles of 5-HTTLPR (S or L_G) exhibited stronger associations between childhood (but not combat) traumatic stress and PTSD symptoms. Affect lability mediated the associations between PTSD symptoms and alcohol dependence symptoms. Behavioral disinhibition mediated associations between PTSD symptoms and conduct related problems. Conditional indirect effects indicated stronger associations between childhood traumatic stress and lability, behavioral disinhibition, alcohol consumption, AUD symptoms, and associated conduct problems via PTSD symptoms among those with the low expression 5-HTTLPR alleles. However, interactions between combat trauma and either childhood trauma or genotype were not significant. The results support the hypothesis that affect lability and behavioral disinhibition are potential intermediate traits with distinct associations with AUD and associated externalizing problems.

The incidence of post-traumatic stress disorder among survivors after earthquakes:a systematic review and meta-analysis

BACKGROUND

Post-traumatic stress disorder (PTSD) is a common psychological disorder caused by unusual threats or catastrophic events. Little is known about the combined incidence of PTSD after earthquakes. This study aimed at evaluating the combined incidence of PTSD among survivors after earthquakes using systematic review and meta-analysis.

METHODS

The electronic databases of PubMed, Embase, Web of Science and PsycARTICLES were searched for relevant articles in this study. Loney criteria were used to assess the quality of eligible articles. The combined incidence of PTSD was estimated by using the Freeman-Tukey double arcsine transformation method. Subgroup analyses were conducted using the following variables: the time of PTSD assessment, gender, educational level, marital status, damage to one's house, bereavement, injury of body and witnessing death.

RESULTS

Forty-six eligible articles containing 76,101 earthquake survivors met the inclusion criteria, of which 17,706 were diagnosed as having PTSD. Using a random effects model, the combined incidence of PTSD after earthquakes was 23.66 %. Moreover, the combined incidence of PTSD among survivors who were diagnosed at not more than 9 months after earthquake was 28.76 %, while for survivors who were diagnosed at over nine months after earthquake the combined incidence was 19.48 %. A high degree of heterogeneity (I(2) = 99.5 %, p<0.001) was observed in the results, with incidence ranging from 1.20 to 82.64 %. The subgroup analyses showed that the incidence of PTSD after earthquake varied significantly across studies in relation to the time of PTSD assessment, gender, educational level, damage to one's house, bereavement, injury of body and witnessing death. However, stratified analyses could not entirely explain the heterogeneity in the results.

CONCLUSIONS

Given the high heterogeneity observed in this study, future studies should aim at exploring more possible risk factors for PTSD after earthquakes, especially genetic factors. In spite of that, the results of this study suggest that nearly 1 in 4 earthquake survivors are diagnosed as having PTSD. Therefore, the local government should plan effective psychological interventions for earthquake survivors.

Careful operationalization and assessment are critical for advancing the study of the neurobiology of resilience

The authors' definition of resilience is too narrow and essentially defines resilience as the absence of psychopathology. Consequently, it is not clear how quantitatively defined resilience differs from quantitatively defined psychopathology according to the authors' definition. We believe the conceptual model would be improved by a broader definition of resilience. There is also a significant need for improved measures of stressor load.

Family composition and symptom severity among Veterans with comorbid PTSD and substance use disorders

Posttraumatic stress disorder (PTSD) and substance use disorders (SUD) frequently co-occur and affect a substantial proportion of military Veterans. Although the impact of parental PTSD and SUD on child development is well-documented, little is known about the influence of family composition on PTSD/SUD symptom severity. The present study investigated children in the home as an independent risk factor for symptom severity in a sample of treatment-seeking Veterans (N = 94; 92% male) with comorbid PTSD/SUD. Twenty-seven percent of the sample had minor children (age 18 or younger) living in the home. Veterans with children in the home evidenced significantly higher PTSD symptomatology as measured by the Clinical Administered PTSD Scale (CAPS; M = 82.65 vs. M = 72.17; t = -2.18; p < .05), and reported using marijuana more frequently than Veterans without children in the home (34% vs. 13% of past 60 days; t = -2.35, p < .05). In a multivariate model, having children in the home accounted for unique variance (ΔR(2) = .07) in PTSD severity after accounting for a range of covariates; however, having children in the home did not account for unique variance in substance use. Directions for future research as well as potential clinical implications for parents seeking treatment for PTSD/SUD are discussed.

Effect of genetic variation in the nicotinic receptor genes on risk for posttraumatic stress disorder

The present study examined the association between genetic variation in the nicotinic receptor gene family (CHRNA2, CHRNA3, CHRNA4, CHRNA5, CHRNA6, CHRNA7, CHRNA9, CHRNA10, CHRNB2, CHRNB3, CHRNB4) and the occurrence of posttraumatic stress disorder (PTSD). Clinical interviews were used to diagnose PTSD in 925 non-Hispanic Black (NHB) and 743 non-Hispanic White (NHW) participants. Trauma history and smoking status were assessed with self-report. No significant main effects or single nucleotide polymorphism (SNP) * smoking interactions were observed among NHB participants; however, among NHW participants, a novel association between rs12898919 in the cholinergic receptor nicotinic alpha-5 (CHRNA5) gene and PTSD was observed. No other significant main effects or SNP * smoking interactions were identified among NHW participants. While preliminary, these findings provide continued support for the hypothesis that the CHRNA5 gene is associated with increased risk for PTSD. Limitations of the present study include cross-sectional design, relatively small sample sizes for genetic research, use of self-report to assess smoking status, and use of different methods to diagnose PTSD. Additional research in other samples of trauma-exposed participants is needed to identify the specific functional variant(s) responsible for the association observed between CHRNA5 and PTSD risk in the present study.

EFFECT OF THE APOE ε4 ALLELE AND COMBAT EXPOSURE ON PTSD AMONG IRAQ/AFGHANISTAN-ERA VETERANS

BACKGROUND

The apolipoprotein E (APOE) ε4 allele has been implicated in a range of neuropsychiatric conditions. The present research examined if the ε4 allele of the APOE gene moderated the effect of combat exposure on posttraumatic stress disorder (PTSD) among Iraq/Afghanistan-era veterans.

METHOD

Participants included 765 non-Hispanic White (NHW) and 859 non-Hispanic Black (NHB) Iraq/Afghanistan-era veterans. A structured interview established psychiatric diagnoses. Combat exposure and PTSD symptom severity were assessed via self-report.

RESULTS

The most common lifetime diagnoses were depression (39.2%), PTSD (38.4%), and alcohol dependence (24.38%). After correcting for multiple comparisons, no significant effects were observed on any of the outcomes among the NHW sample; however, within the NHB sample, significant gene × environment (G × E) interactions were observed for lifetime PTSD (P = .0029) and PTSD symptom severity (P = .0009). In each case, the APOE ε4 allele had no effect on the outcomes when combat exposure was low; however, when combat exposure was high, an additive effect was observed such that ε4 homozygotes exposed to high levels of combat reported the highest rates of PTSD (92%) and the worst symptom severity scores on the Davidson Trauma Scale (M = 79.5).

CONCLUSIONS

Although preliminary, these findings suggest that the APOE ε4 allele, in conjunction with exposure to high levels of combat exposure, may increase veterans' risk for developing PTSD.

RORA and posttraumatic stress trajectories: main effects and interactions with childhood physical abuse history

BACKGROUND

Longitudinal studies of posttraumatic stress (PTS) have documented environmental factors as predictors of trajectories of higher, versus lower, symptoms, among them experiences of childhood physical abuse. Although it is now well-accepted that genes and environments jointly shape the risk of PTS, no published studies have investigated genes, or gene-by-environment interactions (GxEs), as predictors of PTS trajectories. The purpose of this study was to fill this gap.

METHODS AND MATERIALS

We examined associations between variants of the retinoid-related orphan receptor alpha (RORA) gene and trajectory membership among a sample of predominantly non-Hispanic Black urban adults (N = 473). The RORA gene was selected based on its association with posttraumatic stress disorder (PTSD) in the first PTSD genome wide association study. Additionally, we explored GxEs between RORA variants and childhood physical abuse history.

RESULTS

We found that the minor allele of the RORA SNP rs893290 was a significant predictor of membership in a trajectory of consistently high PTS, relatively to a trajectory of consistently low PTS. Additionally, the GxE of rs893290 with childhood physical abuse was significant. Decomposition of the interaction showed that minor allele frequency was more strongly associated with membership in consistently high or decreasing PTS trajectories, relative to a consistently low PTS trajectory, among participants with higher levels of childhood physical abuse.

CONCLUSION

The results of the study provide preliminary evidence that variation in the RORA gene is associated with membership in trajectories of higher PTS and that these associations are stronger among persons exposed to childhood physical abuse. Replication and analysis of functional data are needed to further our understanding of how RORA relates to PTS trajectories.

Genomic predictors of combat stress vulnerability and resilience in U.S. Marines: A genome-wide association study across multiple ancestries implicates PRTFDC1 as a potential PTSD gene

BACKGROUND

Research on the etiology of post-traumatic stress disorder (PTSD) has rapidly matured, moving from candidate gene studies to interrogation of the entire human genome in genome-wide association studies (GWAS). Here we present the results of a GWAS performed on samples from combat-exposed U.S. Marines and Sailors from the Marine Resiliency Study (MRS) scheduled for deployment to Iraq and/or Afghanistan. The MRS is a large, prospective study with longitudinal follow-up designed to identify risk and resiliency factors for combat-induced stress-related symptoms. Previously implicated PTSD risk loci from the literature and polygenic risk scores across psychiatric disorders were also evaluated in the MRS cohort.

METHODS

Participants (N=3494) were assessed using the Clinician-Administered PTSD Scale and diagnosed using the DSM-IV diagnostic criterion. Subjects with partial and/or full PTSD diagnosis were called cases, all other subjects were designated controls, and study-wide maximum CAPS scores were used for longitudinal assessments. Genomic DNA was genotyped on the Illumina HumanOmniExpressExome array. Individual genetic ancestry was determined by supervised cluster analysis for subjects of European, African, Hispanic/Native American, and other descent. To test for association of SNPs with PTSD, logistic regressions were performed within each ancestry group and results were combined in meta-analyses. Measures of childhood and adult trauma were included to test for gene-by-environment (GxE) interactions. Polygenic risk scores from the Psychiatric Genomic Consortium were used for major depressive disorder (MDD), bipolar disorder (BPD), and schizophrenia (SCZ).

RESULTS

The array produced >800K directly genotyped and >21M imputed markers in 3494 unrelated, trauma-exposed males, of which 940 were diagnosed with partial or full PTSD. The GWAS meta-analysis identified the phosphoribosyl transferase domain containing 1 gene (PRTFDC1) as a genome-wide significant PTSD locus (rs6482463; OR=1.47, SE=0.06, p=2.04×10(-9)), with a similar effect across ancestry groups. Association of PRTFDC1 with PTSD in an independent military cohort showed some evidence for replication. Loci with suggestive evidence of association (n=25 genes, p<5×10(-6)) further implicated genes related to immune response and the ubiquitin system, but these findings remain to be replicated in larger GWASs. A replication analysis of 25 putative PTSD genes from the literature found nominally significant SNPs for the majority of these genes, but associations did not remain significant after correction for multiple comparison. A cross-disorder analysis of polygenic risk scores from GWASs of BPD, MDD, and SCZ found that PTSD diagnosis was associated with risk sores of BPD, but not with MDD or SCZ.

CONCLUSIONS

This first multi-ethnic/racial GWAS of PTSD highlights the potential to increase power through meta-analyses across ancestry groups. We found evidence for PRTFDC1 as a potential novel PTSD gene, a finding that awaits further replication. Our findings indicate that the genetic architecture of PTSD may be determined by many SNPs with small effects, and overlap with other neuropsychiatric disorders, consistent with current findings from large GWAS of other psychiatric disorders.

Offspring psychological and biological correlates of parental posttraumatic stress: review of the literature and research agenda

Millions of individuals with posttraumatic stress disorder (PTSD) are parents. A burgeoning literature suggests that offspring of parents with this condition may be at increased risk for psychological problems. The current paper provides an integrative and comprehensive review of the diverse research literature examining the sequelae of parental posttraumatic stress among offspring. Over 100 studies that evaluated psychological and/or biological variables among children of parents with PTSD are reviewed. Findings suggest parental symptoms of posttraumatic stress are uniquely related to an array of offspring outcomes, including internalizing-type problems, general behavioral problems, and altered hypothalamic-pituitary-adrenal axis functioning. Although very little work has directly evaluated mechanisms of transmission, there is increasing support for genetic and epigenetic effects as well as parenting behaviors. These and other mechanisms are discussed; drawing upon findings from other literatures to consider how parental PTSD may impart psychobiological vulnerability upon offspring. We conclude with a detailed discussion of the methodological strengths and challenges of the extant research, along with a recommended agenda for future research in this important area of study.

Meta-analyses of the 5-HTTLPR polymorphisms and post-traumatic stress disorder

Objective

To conduct a meta-analysis of all published genetic association studies of 5-HTTLPR polymorphisms performed in PTSD cases

Methods Data Sources

Potential studies were identified through PubMed/MEDLINE, EMBASE, Web of Science databases (Web of Knowledge, WoK), PsychINFO, PsychArticles and HuGeNet (Human Genome Epidemiology Network) up until December 2011. Study Selection: Published observational studies reporting genotype or allele frequencies of this genetic factor in PTSD cases and in non-PTSD controls were all considered eligible for inclusion in this systematic review. Data Extraction: Two reviewers selected studies for possible inclusion and extracted data independently following a standardized protocol. Statistical analysis: A biallelic and a triallelic meta-analysis, including the total S and S' frequencies, the dominant (S+/LL and S'+/L'L') and the recessive model (SS/L+ and S'S'/L'+), was performed with a random-effect model to calculate the pooled OR and its corresponding 95% CI. Forest plots and Cochran's Q-Statistic and I² index were calculated to check for heterogeneity. Subgroup analyses and meta-regression were carried out to analyze potential moderators. Publication bias and quality of reporting were also analyzed.

Results

13 studies met our inclusion criteria, providing a total sample of 1874 patients with PTSD and 7785 controls in the biallelic meta-analyses and 627 and 3524, respectively, in the triallelic. None of the meta-analyses showed evidence of an association between 5-HTTLPR and PTSD but several characteristics (exposure to the same principal stressor for PTSD cases and controls, adjustment for potential confounding variables, blind assessment, study design, type of PTSD, ethnic distribution and Total Quality Score) influenced the results in subgroup analyses and meta-regression. There was no evidence of potential publication bias.

Conclusions

Current evidence does not support a direct effect of 5-HTTLPR polymorphisms on PTSD. Further analyses of gene-environment interactions, epigenetic modulation and new studies with large samples and/or meta-analyses are required.

Adcyap1r1 genotype, posttraumatic stress disorder, and depression among women exposed to childhood maltreatment

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.

Gene-environment interaction in panic disorder and posttraumatic stress disorder

Gene-environment interaction is a form of causal interplay, whereby genetic effects on phenotypic variation change as a function of environmental exposure. While conceptually appealing, there is still much debate on the veracity and the relevance of this form of etiological interdependence for psychiatric disorders. By focusing on panic disorder (PD) and posttraumatic stress disorder (PTSD), this article outlines why gene-environment interaction is controversial, why it can be important for both researchers and clinicians, and how it is investigated by quantitative genetic, molecular genetic, and genomic strategies. It is suggested that gene-environment interaction effects are more reliable and meaningful when they can be harnessed to pinpoint specific biological pathways and mechanisms. In psychiatry, this can be guided by phenotypic dissection and realized by adopting intermediate phenotypes of a physiological nature, such as carbon dioxide sensitivity for PD, or gene expression profiling after stress for PTSD. A developmental framework of reference and the possibility of transferring the investigation to animal models are additional key elements in this debate.

Considering trauma exposure in the context of genetics studies of posttraumatic stress disorder: a systematic review

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.

A consideration of select pre-trauma factors as key vulnerabilities in PTSD

Posttraumatic stress disorder (PTSD) is a pathological response to a traumatic event. A number of risk and vulnerability factors predicting PTSD development have been identified in the literature. Many of these variables are specific factors occurring during and after exposure to a traumatic event or are not measured prospectively to assess temporal sequence. Recent research, however, has begun to focus on pre-trauma individual differences that could contribute to risk for developing PTSD. The present review proposes that a number of biological and cognitive vulnerability factors place individuals at risk for PTSD development prior to the actual experience of trauma. Accordingly, this review provides a summary of evidence for a select number of these factors as pre-trauma vulnerabilities to PTSD. Included is a discussion of biological factors, including molecular genetic studies of systems regulating serotonin, catecholamines, and glucocorticoids as well as aspects of the neuroendocrine system. Specific cognitive factors are also considered, including intelligence, neuropsychological functioning and cognitive biases such as negative attributional style and appraisals. For each factor, the present review summarizes evidence to date regarding PTSD vulnerability and highlights directions for future research in this area.

Suicide among war veterans

Studies aiming to identify if war veterans are at higher risk of suicide have often produced inconsistent results; this could be due to the complexity of comparisons and different methodological approaches. It should be noted that this contingent has many risk factors, such as stressful exposures, wounds, brain trauma and pain syndrome. Most recent observations confirm that veterans are really more likely to die of suicide as compared to the general population; they are also more likely to experience suicidal ideation and suffer from mental health problems. Suicides are more frequent in those who develop PTSD, depression and comorbid states due to war exposure. Combat stress and its’ frequency may be an important factor leading to suicide within the frame of the stress-vulnerability model. According to this model, the effects of stress may interact with social factors, interpersonal relations and psychological variables producing suicidal tendencies. Modern understanding of stress-vulnerability mechanisms based on genetic predispositions, early life development, level of exposure to stress and stress-reactivity together with interpersonal aspects may help to build more effective suicide prevention programs based on universal/selective/indicated prevention principles.

Symptom persistence and memory performance in posttraumatic stress disorder: a gene x environment pilot stud

The FKBP5 gene, a glucocorticoid receptor (GR)-regulating co-chaperone of stress proteins, is of special interest because of its role in hypothalamic-pituitary-adrenal (HPA)-axis regulation. However, studies finding a genetic relationship between posttraumatic stress disorder (PTSD) and the FKBP5 gene have failed to distinguish between the development and persistence of PTSD, thereby limiting the prognostic usefulness of such a finding. The present study sought to longitudinally explore this question by examining the association between four single-nucleotide polymorphisms (SNPs) in the FKBP5 gene (rs3800373, rs9470080, rs1360780, and rs9296158), the persistence of PTSD (severity and diagnostic status), and memory performance among twenty-two treatment-seekers diagnosed with acute PTSD. Results showed that the four SNPs significantly interacted with improvement in PTSD symptoms as well as PTSD diagnostic status. Individuals homozygous for the dominant allele and having experienced higher levels of peritraumatic responses subsequently showed more memory dysfunction. The results of this study suggest that SNPs in the FKBP5 gene are associated with symptom persistence and memory dysfunction in acute PTSD.