Alcohol use and alcohol use disorder differ in their genetic relationships with PTSD: A genomic structural equation modelling approach

PURPOSE

Posttraumatic Stress Disorder (PTSD) is associated with increased alcohol use and alcohol use disorder (AUD), which are all moderately heritable. Studies suggest the genetic association between PTSD and alcohol use differs from that of PTSD and AUD, but further analysis is needed.

BASIC PROCEDURES

We used genomic Structural Equation Modeling (genomicSEM) to analyze summary statistics from large-scale genome-wide association studies (GWAS) of European Ancestry participants to investigate the genetic relationships between PTSD (both diagnosis and re-experiencing symptom severity) and a range of alcohol use and AUD phenotypes.

MAIN FINDINGS

When we differentiated genetic factors for alcohol use and AUD we observed improved model fit relative to models with all alcohol-related indicators loading onto a single factor. The genetic correlations (rG) of PTSD were quite discrepant for the alcohol use and AUD factors. This was true when modeled as a three-correlated-factor model (PTSD-AUD rG:.36, p < .001; PTSD-alcohol use rG: -0.17, p < .001) and as a Bifactor model, in which the common and unique portions of alcohol phenotypes were pulled out into an AUD-specific factor (rG with PTSD:.40, p < .001), AU-specific factor (rG with PTSD: -0.57, p < .001), and a common alcohol factor (rG with PTSD:.16, NS).

PRINCIPAL CONCLUSIONS

These results indicate the genetic architecture of alcohol use and AUD are differentially associated with PTSD. When the portions of variance unique to alcohol use and AUD are extracted, their genetic associations with PTSD vary substantially, suggesting different genetic architectures of alcohol phenotypes in people with PTSD.

Identifying Frequency of Mild Traumatic Brain Injury in Firefighters

Background: Mild traumatic brain injury (mTBI) is a nationwide problem; yet, no firefighter mTBI data are available. Methods: In this cross-sectional study, we assessed retrospective head injuries using WHO guidelines. We captured mTBI frequency and examined firefighters' symptoms (e.g., using Ohio State University Traumatic Brain Injury Identification method, Brief Traumatic Brain Injury Screen, Warrior Administered Retrospective Causality Assessment Tool). Findings: Of 1,112 firefighters contacted, 60 responses were included. Most participants were White (80%), male (90%), former athletes (75%). 62% met mTBI symptom criteria. 75% reported at least one lifetime head injury. Number of head injuries and depression symptoms were associated (r = .36, p < .05). Conclusion/application to practice: Overall, it appears most firefighters have sustained at least one lifetime mTBI. Those with multiple head injuries may be at increased risk of depression. Occupational health professionals should be aware of firefighters' mTBI risk. Further research is warranted given findings.

Psychosocial protective factors and suicidal ideation: Results from a national longitudinal study of veterans

BACKGROUND

This study investigates the empirical association between psychosocial protective factors and subsequent suicidal ideation in veterans.

METHODS

We conducted a national longitudinal survey in which participants were randomly drawn from over one million U.S. military service members who served after September 11, 2001. Data were provided by a total of 1090 veterans representative of all 50 states and all military branches in two waves of data collection one year apart (79% retention rate).

RESULTS

In chi-square analyses, psychosocial protective factors at wave 1 (employment, meeting basic needs, self-care, living stability, social support, spirituality, resilience, and self-determination) were significantly related to lower suicidal ideation at wave 2. In multivariable analyses controlling for covariates at wave 1 including suicidal ideation, the total number of protective factors endorsed at wave 1 significantly predicted reduced odds of suicidal ideation at wave 2. In multivariable analysis examining individual risk and protective factors, again controlling for covariates, results showed that money to cover basic needs and higher psychological resilience at wave 1 were associated with significantly lower odds of suicidal ideation at wave 2.

LIMITATIONS

The study measured the link between psychosocial protective factors and suicidal ideation but not suicide attempts, which would be an important next step for this research.

CONCLUSIONS

The results indicate that psychosocial rehabilitation and holistic approaches targeting financial well-being, homelessness, resilience, self-care, social support, spirituality, and work may offer a promising avenue in both veteran and non-veteran populations for treatment safety planning as well as suicide risk management and prevention.

Roles of Guilt Cognitions in Trauma-Related Sleep Disturbance in Military Veterans With Posttraumatic Stress Disorder

Objective/Background: Despite a well-established role of guilt cognitions in the maintenance and treatment of posttraumatic stress disorder (PTSD), relationships of guilt cognitions to nightmares are not well understood. This study investigated the ways in which guilt cognitions, related to traumatic events, influenced the relationship between combat exposure and trauma-related sleep disturbance in military Veterans with PTSD. Participants: We recruited a sample of 50 Veterans with PTSD who completed study measures at a screening session. Methods: Participants completed self-report measures of exposure to potentially traumatic events, trauma-related guilt (hindsight bias, wrongdoing, and lack of justification) and trauma-related sleep disturbance as measured by a self-report scale and clinician ratings of nightmare severity. Results: Bivariate regression analyses established a relationship of combat exposure to wrongdoing (β = .31, p = .031), and a relationship of wrongdoing with self-reported trauma-related sleep disturbance (β = .27, p = .049) and clinician-rated nightmare severity (β = .36, p = .009). Bootstrapping analysis that included years of education as a covariate found a significant overall indirect effect of combat exposure on clinician-rated nightmare severity exerted through wrongdoing (β = .10, 95% CI [.004, .246]). Conclusions: Results suggest the association of combat exposure with trauma-related sleep disturbance is significantly influenced by perceived wrongdoing related to a traumatic event. Targeting cognitions related to wrongdoing and moral injury during a traumatic event in PTSD treatment may help ameliorate trauma-related sleep disturbance.