A comparison of methods to harmonize cortical thickness measurements across scanners and sites.

Results of neuroimaging datasets aggregated from multiple sites may be biased by site-specific profiles in participants' demographic and clinical characteristics, as well as MRI acquisition protocols and scanning platforms. We compared the impact of four different harmonization methods on results obtained from analyses of cortical thickness data: (1) linear mixed-effects model (LME) that models site-specific random intercepts (LMEINT), (2) LME that models both site-specific random intercepts and age-related random slopes (LMEINT+SLP), (3) ComBat, and (4) ComBat with a generalized additive model (ComBat-GAM). Our test case for comparing harmonization methods was cortical thickness data aggregated from 29 sites, which included 1,340 cases with posttraumatic stress disorder (PTSD) (6.2-81.8 years old) and 2,057 trauma-exposed controls without PTSD (6.3-85.2 years old). We found that, compared to the other data harmonization methods, data processed with ComBat-GAM was more sensitive to the detection of significant case-control differences (Χ2(3) = 63.704, p < 0.001) as well as case-control differences in age-related cortical thinning (Χ2(3) = 12.082, p = 0.007). Both ComBat and ComBat-GAM outperformed LME methods in detecting sex differences (Χ2(3) = 9.114, p = 0.028) in regional cortical thickness. ComBat-GAM also led to stronger estimates of age-related declines in cortical thickness (corrected p-values < 0.001), stronger estimates of case-related cortical thickness reduction (corrected p-values < 0.001), weaker estimates of age-related declines in cortical thickness in cases than controls (corrected p-values < 0.001), stronger estimates of cortical thickness reduction in females than males (corrected p-values < 0.001), and stronger estimates of cortical thickness reduction in females relative to males in cases than controls (corrected p-values < 0.001). Our results support the use of ComBat-GAM to minimize confounds and increase statistical power when harmonizing data with non-linear effects, and the use of either ComBat or ComBat-GAM for harmonizing data with linear effects.

Prevalence and covariates of problematic gambling among a US military cohort.

The availability of and participation in gambling has increased substantially the past several decades, however studies of military members' gambling behaviors are limited. The present study aimed to investigate potential problematic gambling and its association with demographics and behavioral characteristics in a US military cohort. We analyzed cohort data from a telephone survey during 2015-2016 of 1553 Ohio Army National Guard members. We assessed potential problematic gambling by using the 3-item National Opinion Research Center Diagnostic Screen-Loss of Control, Lying, and Preoccupation Screen (NODS-CLiP). Potential correlates examined were demographics, depression, suicidal ideation, smoking status, alcohol use, legal and financial problems, perceived general health status, pain, and impulsivity. Results indicated past-year frequent gambling (at least once per week) and lifetime potential problematic gambling was reported by 13% and 8% of respondents, respectively. Problematic gambling and past-year gambling behaviors were associated in a dose-response relationship from 18% among soldiers gambling once per week to 44% among those gambling 4 or more times per week. Correlates of screening positive for potential problematic gambling included the following: being male, currently unmarried, having left the Guard or retired, minor depression, alcohol dependence, legal problems, and increased pain. Given the higher prevalence of frequent gambling in this military cohort (8%), nearly twice the US prevalence (5%), and the association with negative psychological and behavioral outcomes, routine screening of gambling frequency and problem gambling may be needed to ensure military and veteran populations live the healthiest lives possible.

Relationship of Hippocampal Volumes and Posttraumatic Stress Disorder Symptoms Over Early Posttrauma Periods.

BACKGROUND: Smaller hippocampal volume is associated with more severe posttraumatic stress disorder (PTSD) symptoms years after traumatic experiences. Posttraumatic stress symptoms appear early following trauma, but the relationship between hippocampal volume and PTSD symptom severity during early posttrauma periods is not well understood. It is possible that the inverse relationship between hippocampal volume and PTSD symptom severity is already present soon after trauma. To test this possibility, we prospectively examined the association between hippocampal volumes and severity of PTSD symptoms within weeks to months after trauma due to a motor vehicle collision. METHODS: Structural magnetic resonance imaging scans of 44 survivors were collected about 2 weeks and again at 3 months after a motor vehicle collision to measure hippocampal volumes. The PTSD Checklist was used to evaluate PTSD symptoms at each scan time. Full (n = 5) or partial (n = 6) PTSD was evaluated using the Clinician-Administered PTSD Scale at 3 months. RESULTS: Left hippocampal volumes at both time points negatively correlated with PTSD Checklist scores, and with subscores for re-experiencing symptoms at 3 months. Left hippocampal volumes at 3 months also negatively correlated with hyperarousal symptoms at 3 months. Finally, neither left nor right hippocampal volumes significantly changed between 2 weeks and 3 months posttrauma. CONCLUSIONS: The results suggest that small hippocampal volume at early posttrauma weeks is associated with increased risk for PTSD development. Furthermore, the inverse relationship between hippocampal volume and PTSD symptoms at 3 months did not arise from posttrauma shifts in hippocampal volume between 2 weeks and 3 months after trauma.

Subthreshold PTSD and PTSD in a prospective-longitudinal cohort of military personnel: Potential targets for preventive interventions.

BACKGROUND: Prevention of PTSD requires identification of subpopulations contributing most to the population burden of PTSD. This study examines the relative contribution of subthreshold PTSD and probable PTSD on future PTSD in a representative military cohort. METHODS: We analyze data on 3,457 U.S. National Guard members from the state of Ohio, assessed by telephone annually from 2008 to 2014. At each wave, participants were classified into one of three groups based on the PTSD Checklist: probable PTSD (DSM-IV-TR criteria), subthreshold PTSD (Criterion A1, at least one symptom in each cluster, symptom lasting longer than 30 days, and functional impairment), and no PTSD. We calculated the exposure rate, risk ratio (RR), and population attributable fraction (PAF) to determine the burden of future probable PTSD attributable to subthreshold PTSD compared to probable PTSD. RESULTS: The annualized prevalence of subthreshold PTSD and probable PTSD was respectively 11.9 and 5.0%. The RR for probable PTSD was twice as great among respondents with probable PTSD the prior interview than that of those with subthreshold PTSD (7.0 vs. 3.4); however, the PAF was considerably greater in participants with subthreshold PTSD the prior interview (PAF = 35%; 95% confidence interval (CI) = 26.0-42.9%) than in those with probable PTSD (PAF = 28.0%; 95% CI = 21.8-33.8%). Results were robust to changes in subthreshold PTSD definition. CONCLUSIONS: Subthreshold PTSD accounted for a substantial proportion of this population's future PTSD burden. Population-based preventive interventions, compared to an approach focused exclusively on cases of diagnosable PTSD, is likely to affect the greatest reduction in this population's future PTSD burden.

Deployment and Alcohol Use in a Military Cohort: Use of Combined Methods to Account for Exposure-Related Covariates and Heterogeneous Response to Exposure.

Studies have shown that combat-area deployment is associated with increases in alcohol use; however, studying the influence of deployment on alcohol use faces 2 complications. First, the military considers a confluence of factors before determining whether to deploy a service member, creating a nonignorable exposure and unbalanced comparison groups that inevitably complicate inference about the role of deployment itself. Second, regression analysis assumes that a single effect estimate can approximate the population's change in postdeployment alcohol use, which ignores previous studies that have documented that respondents tend to exhibit heterogeneous postdeployment drinking behaviors. Therefore, we used propensity score matching to balance baseline covariates for the 2 comparison groups (deployed and nondeployed), followed by a variable-oriented difference-in-differences approach to account for the confounding and a person-oriented approach using a latent growth mixture model to account for the heterogeneous response to deployment in this prospective cohort study of the US Army National Guard (2009-2014). We observed a nonsignificant increase in estimated monthly drinks in the first year after deployment that regressed to predeployment drinking levels 2 years after deployment. We found a 4-class model that fit these data best, suggesting that common regression analyses likely conceal substantial interindividual heterogeneity in postdeployment alcohol-use behaviors.

Coincident alcohol dependence and depression increases risk of suicidal ideation among Army National Guard soldiers.

PURPOSE: Suicide rates among military service members have risen dramatically, while drivers remain poorly understood. We examined the relationship between coincident alcohol dependence and depression in shaping risk of suicidal ideation among National Guard forces. METHODS: We performed a longitudinal analysis using a randomly selected, population-based sample of Ohio Army National Guard soldiers. Telephone-based surveys of 1582 soldiers who participated in both wave 1 (2008-2009) and wave 2 (2009-2010) were analyzed. RESULTS: Odds ratios (ORs) for suicidal ideation among those with versus without alcohol dependence were similar among nondepressed (OR = 3.85 [95% confidence intervals (CIs) = 1.18-12.52]) and depressed individuals (OR = 3.13 [95% CI = 0.88-11.14]); multiplicative interaction was not observed. In contrast, the risk differences (RDs) among those with versus without alcohol dependence diverged for those without depression (RD = 0.04 [95% CI = 0.02-0.07]) compared with those with depression (RD = 0.11 [95% CI = 0.06-0.18]); strong evidence of additive interaction was observed. CONCLUSIONS: We found that alcohol dependence and depression interact statistically in shaping risk for incident suicidal ideation among Army National Guard service members. A high-risk prevention approach including population-based screening for suicidality among patients with alcohol dependence, depression, and particularly those with both conditions is warranted in military populations.

General distress is more important than PTSD's cognition and mood alterations factor in accounting for PTSD and depression's comorbidity.

BACKGROUND: Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) are highly comorbid and exhibit strong correlations with each other at both the symptom level and latent factor level. Various theories have attempted to explain this relationship. Results have been inconsistent regarding whether PTSD's negative alterations in cognition and mood factor (NACM) is significantly more related to depression, in contrast to other factors of PTSD. METHODS: Confirmatory factor analysis was used to attempt to address the relationships between PTSD and MDD in a large sample of trauma-exposed combat veterans from the Ohio National Guard as part of a larger longitudinal study. RESULTS: Confirmatory factor analysis was used to test a bifactor model of PTSD symptoms, testing relations between PTSD's factors and a latent depressive factor. After partitioning out the common variance into the bifactor, we found that in contrast to other PTSD factors, PTSD's NACM factor was not significantly more related to depression. Instead, only the general bifactor predicted depressive symptoms. LIMITATIONS: The limitations of the present study include the following: the specific measures of PTSD and MDD used were based on self-report, and the sample consisted of non-clinical, non-treatment seeking veterans. CONCLUSIONS: The present study suggests that the high rate of comorbidity between posttraumatic stress disorder (PTSD) and major depressive disorder is more related to underlying general distress or negative affectivity than the symptom categories of the PTSD diagnostic criteria.

Early Changes in Cortical Emotion Processing Circuits after Mild Traumatic Brain Injury from Motor Vehicle Collision.

Mild traumatic brain injury (mTBI) patients frequently experience emotion dysregulation symptoms, including post-traumatic stress. Although mTBI likely affects cortical activation and structure, resulting in cognitive symptoms after mTBI, early effects of mTBI on cortical emotion processing circuits have rarely been examined. To assess early mTBI effects on cortical functional and structural components of emotion processing, we assessed cortical activation to fearful faces within the first 2 weeks after motor vehicle collision (MVC) in survivors who did and did not experience mTBI. We also examined the thicknesses of cortical regions with altered activation. MVC survivors with mTBI (n = 21) had significantly less activation in left superior parietal gyrus (SPG) (-5.9, -81.8, 33.8; p = 10-3.623), left medial orbitofrontal gyrus (mOFG) (-4.7, 36.1, -19.3; p = 10-3.231), and left and right lateral orbitofrontal gyri (lOFG) (left: -16.0, 41.4, -16.6; p = 10-2.573; right: 18.7, 22.7, -17.7; p = 10-2.764) than MVC survivors without mTBI (n = 23). SPG activation in mTBI survivors within 2 weeks after MVC was negatively correlated with subsequent post-traumatic stress symptom severity at 3 months (r = -0.68, p = 0.03). Finally, the SPG region was thinner in the mTBI survivors than in the non-mTBI survivors (F = 11.07, p = 0.002). These results suggest that early differences in activation and structure in cortical emotion processing circuits in trauma survivors who sustain mTBI may contribute to the development of emotion-related symptoms.

Incidence and Risk for Mood and Anxiety Disorders in a Representative Sample of Ohio Army National Guard Members, 2008-2012.

OBJECTIVE: We investigated the incidence of first-onset psychiatric disorders among Ohio Army National Guard members and the sociodemographic and military factors associated with these incident disorders. We aimed to identify potential risk factors and mitigating factors for a range of psychiatric disorders in a representative military sample. METHODS: We analyzed data on a representative sample of 528 Ohio Army National Guard members who were assessed in person annually for first-onset psychiatric disorders from 2008 through 2012 using structured clinical interviews. We used a multivariable discrete-time Cox proportional hazard model to determine risk factors of first-onset anxiety or mood disorders. RESULTS: The annualized incidence rate of any first-onset psychiatric disorder was 9.8 per 100 person-years at risk. Alcohol use disorder and major depressive disorder had the highest incidence rates among the unique disorders under study (5.0 and 4.2 per 100 person-years at risk, respectively). We found an association between respondents endorsing past-year deployment and a 29% increase in the risk of incident anxiety or mood disorder, whereas the past-year experience of any non-deployment traumatic event was associated with a 32% increase in risk of incident anxiety or mood disorder. CONCLUSION: Soldiers experience a substantial burden of first-onset alcohol use disorder and major depressive disorder annually; the experience of non-deployment-related traumatic events contributes substantially to increasing risk, suggesting that any effort aimed at mitigating mood and anxiety disorders in this population must consider the soldier's life experience and military experience.

Preliminary Study of Acute Changes in Emotion Processing in Trauma Survivors with PTSD Symptoms.

Accumulating evidence suggests traumatic experience can rapidly alter brain activation associated with emotion processing. However, little is known about acute changes in emotion neurocircuits that underlie PTSD symptom development. To examine acute alterations in emotion circuit activation and structure that may be linked to PTSD symptoms, thirty-eight subjects performed a task of appraisal of emotional faces as their brains were functionally and structurally studied with MRI at both two weeks and three months after motor vehicle collision (MVC). As determined by symptoms reported in the PTSD Checklist at three months, sixteen survivors developed probable PTSD, whereas the remaining 22 did not meet criteria for PTSD diagnosis (non-PTSD). The probable PTSD group had greater activation than the non-PTSD group in dorsal and ventral medial prefrontal cortex (dmPFC and vmPFC) while appraising fearful faces within two weeks after MVC and in left insular cortex (IC) three months after MVC. dmPFC activation at two weeks significantly positively correlated with PTSD symptom severity at two weeks (R = 0.462, P = 0.006) and three months (R = 0.418, p = 0.012). Changes over time in dmPFC activation and in PTSD symptom severity were also significantly positively correlated in the probable PTSD group (R = 0.641, P = 0.018). A significant time by group interaction was found for volume changes in left superior frontal gyrus (SFG, F = 6.048, p = 0.019) that partially overlapped dmPFC active region. Between two weeks and three months, left SFG volume decreased in probable PTSD survivors. These findings identify alterations in frontal cortical activity and structure during the early post-trauma period that appear to be associated with development of PTSD symptoms.

Retrospective age-of-onset and projected lifetime prevalence of psychiatric disorders among U.S. Army National Guard soldiers.

BACKGROUND: The study of military-related mental health has been disproportionately focused on current symptomology rather than potentially more informative life course mental health. Indeed, no study has assessed age-of-onset and projected lifetime prevalence of disorders among reservists. METHODS: Age-of-onset and projected lifetime DSM-IV anxiety, mood, and substance use disorders were assessed in 671 Ohio Army National Guard soldiers aged 17-60 years. Between 2008 and 2012, face-to-face clinical assessments and surveys were conducted using the Structured Clinical Interview for DSM-IV and Clinician-Administered PTSD Scale. RESULTS: Lifetime prevalence of psychiatric disorders was 61%. Alcohol abuse/dependence (44%) and major depressive disorder (23%) were the most common disorders. The majority (64%) of participants reported disorders antedating enlistment. Median age-of-onset varied with anxiety disorders - particularly phobias and OCD - having the earliest (median=15 years) and mood disorders the latest median age-of-onset (median=21 years). LIMITATIONS: The study was limited by both the retrospective investigation of age-of-onset and the location of our sample. As our sample may not represent the general military population, our findings need to be confirmed in additional samples. CONCLUSIONS: Each psychiatric disorder exhibited a distinct age-of-onset pattern, such that phobias and OCD onset earliest, substance use disorders onset during a short interval from late-adolescence to early-adulthood, and mood disorders onset the latest. Our finding that the majority of participants reported disorders antedating enlistment suggests that an assessment of lifetime psychopathology is essential to understanding the mental health burden of both current and former military personnel.

Association of Spirituality With Mental Health Conditions in Ohio National Guard Soldiers.

Research exploring spirituality in military populations is a relatively new field with limited published reports. This study used the Spiritual Well-Being Scale to examine the association of spiritual well-being with suicidal ideation/behavior, posttraumatic stress disorder (PTSD), and depression and alcohol use disorders in a randomized sample of Ohio Army National Guard soldiers. The participants were 418 soldiers, mostly white and male, with nearly three-quarters indicating that they had been deployed at least once during their careers. Higher spirituality, especially in the existential well-being subscale, was associated with significantly less lifetime PTSD, depression, and alcohol use disorders and with less suicidal ideation over the past year. Future research in this area may benefit from a longitudinal design that can assess spirituality and mental health behaviors in addition to diagnoses at different time points, to begin to explore spirituality in a larger context.

Latent dimensions of posttraumatic stress disorder and their relations with alcohol use disorder.

PURPOSE: The objective of this study was to evaluate the relationship between factors of posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) using confirmatory factor analysis (CFA) in order to further our understanding of the substantial comorbidity between these two disorders. METHODS: CFA was used to examine which factors of PTSD's dysphoria model were most related to AUD in a military sample. Ohio National Guard soldiers with a history of overseas deployment participated in the survey (n = 1215). Participants completed the PTSD Checklist and a 12-item survey from the National Survey on Drug Use used to diagnosis AUD. RESULTS: The results of the CFA indicated that a combined model of PTSD's four factors and a single AUD factor fit the data very well. Correlations between PTSD's factors and a latent AUD factor ranged from correlation coefficients of 0.258-0.285, with PTSD's dysphoria factor demonstrating the strongest correlation. However, Wald tests of parameter constraints revealed that AUD was not more correlated with PTSD's dysphoria than other PTSD factors. CONCLUSIONS: All four factors of PTSD's dysphoria model demonstrate comparable correlations with AUD. The role of dysphoria to the construct of PTSD is discussed.

Onset of Alcohol Use Disorders and Comorbid Psychiatric Disorders in a Military Cohort: Are there Critical Periods for Prevention of Alcohol Use Disorders?

Alcohol use disorders (AUD) are commonly comorbid with anxiety and mood disorders; however, a strategy for AUD prevention remains unclear in the presence of three competing etiological models that each recommends different high-risk groups. Therefore, the investigation of the three hypotheses in a characteristically unique cohort is critical to identifying pervasive characteristics of AUD that can inform a universal prevention strategy. The current study evaluated the temporality and onset of comorbid AUD and psychiatric disorders in a representative sample of 528 Ohio Army National Guard soldiers using structured clinical interviews from 2009 to 2012. We examined temporality both statistically and graphically to identify patterns that could inform prevention. General estimating equations with dichotomous predictor variables were used to estimate odds ratios between comorbid psychiatric disorders and AUDs. An annualized rate of 13.5 % persons per year was diagnosed with any AUD between 2010 and 2012. About an equal proportion of participants with comorbid psychiatric disorders and AUD initiated the psychiatric disorder prior to the AUD and half initiated the psychiatric disorder after the AUD. Regardless of onset, however, the majority (80 %) AUD initiated during a short interval between the ages of 16 and 23. Focused primary prevention during this narrow age range (16-23 years) may have the greatest potential to reduce population mental health burden of AUD, irrespective of the sequencing of comorbid psychiatric disorder.

Mental Health Over Time in a Military Sample: The Impact of Alcohol Use Disorder on Trajectories of Psychopathology After Deployment.

To identify trajectories of depression and posttraumatic stress (PTS) symptom groups after deployment and determine the effect of alcohol use disorder on these trajectories, depression symptoms were modeled using the 9-item Patient Health Questionnaire in 727 Ohio National Guard members, and PTS symptoms were modeled using the PTSD Checklist in 472 Ohio National Guard members. There were 55.8% who were resistant to depression symptoms across the 4 years of study, and 41.5% who were resistant to PTS symptoms. There were 18.7% and 42.2% of participants who showed resilience (experiencing slightly elevated symptoms followed by a decline, according to Bonanno et al., 2002) to depression and PTS symptoms, respectively. Mild and chronic dysfunction constituted the smallest trajectory groups across disorders. Marital status, deployment to an area of conflict, and number of lifetime stressors were associated with membership into different latent groups for depression (unstandardized ß estimates range = 0.69 to 1.37). Deployment to an area of conflict, number of lifetime traumatic events and education predicted membership into different latent groups for PTS (significant unstandardized ß estimate range = 0.83 to 3.17). AUD was associated with an increase in both symptom outcomes (significant unstandardized ß estimate range = 0.20 to 9.45). These results suggested that alcohol use disorder may have contributed substantially to trajectories of psychopathology in this population.

Adverse Childhood Events and the Risk for New-Onset Depression and Post-Traumatic Stress Disorder Among U.S. National Guard Soldiers.

This article examines the relationship between childhood adversity and postdeployment new-onset psychopathology among a sample of U.S. National Guard personnel deployed during Operation Iraqi Freedom and Operation Enduring Freedom with no history of post-traumatic stress disorder (PTSD) or depression. We recruited a sample of 991 Ohio Army National Guard soldiers and conducted structured interviews to assess traumatic event exposure, a history of childhood adversity, and postdeployment depression, and PTSD, consistent with the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition. We assessed childhood adversity by using questions from the Childhood Adverse Events Survey. In multivariable logistic models, a history of any childhood adversity was significantly associated with new-onset depression, but not PTSD, postdeployment. This finding suggests that a history of childhood adversity is predisposing for new-onset depression, among U.S. National Guard soldiers who were deployed with no prior history of PTSD or depression. This highlights the centrality of childhood experience for the production of mental health among soldiers.

Latent profile analyses of posttraumatic stress disorder, depression and generalized anxiety disorder symptoms in trauma-exposed soldiers.

Posttraumatic stress disorder (PTSD) is comorbid with major depressive disorder (MDD; Kessler et al., 1995) and generalized anxiety disorder (GAD; Brown et al., 2001). We aimed to (1) assess discrete patterns of post-trauma PTSD-depression-GAD symptoms using latent profile analyses (LPAs), and (2) assess covariates (gender, income, education, age) in defining the best fitting class solution. The PTSD Checklist (assessing PTSD symptoms), GAD-7 scale (assessing GAD symptoms), and Patient Health Questionnaire-9 (assessing depression) were administered to 1266 trauma-exposed Ohio National Guard soldiers. Results indicated three discrete subgroups based on symptom patterns with mild (class 1), moderate (class 2) and severe (class 3) levels of symptomatology. Classes differed in symptom severity rather than symptom type. Income and education significantly predicted class 1 versus class 3 membership, and class 2 versus class 3. In conclusion, there is heterogeneity regarding severity of PTSD-depression-GAD symptomatology among trauma-exposed soldiers, with income and education predictive of class membership.

Posttraumatic stress disorder's dysphoria dimension and relations with generalized anxiety disorder symptoms.

The present study investigated symptom relations between two highly comorbid disorders--posttraumatic stress disorder (PTSD) and generalized anxiety disorder (GAD)--by exploring their underlying dimensions. Based on theory and prior empirical research it was expected that the dysphoria factor of PTSD would be more highly related to GAD. As part of a longitudinal project of mental health among Ohio National Guard Soldiers, 1266 subjects were administered the Posttraumatic Stress Disorder Checklist (PCL) and Generalized Anxiety Disorder-7 scale (GAD-7). Confirmatory factor analyses (CFAs) were conducted to examine two models of PTSD and to determine which PTSD factors were more related to the GAD factor. The results indicate that the GAD factor was significantly more highly correlated with PTSD's dysphoria factor than with all other PTSD factors, including PTSD's reexperiencing factor, avoidance factor, and hyperarousal factor. Results indicate GAD was not significantly more highly correlated with numbing than most other factors of PTSD. The results are consistent with prior research. Implications of the results are discussed in regards to PTSD in DSM-5, comorbidity and diagnostic specificity.

Structural relations between DSM-5 PTSD and major depression symptoms in military soldiers.

BACKGROUND: Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) are frequently comorbid. One explanation for this comorbidity is that PTSD has a constellation of "dysphoria" symptoms resembling depression. METHOD: Using confirmatory factor analysis we tested the role of DSM-5 PTSD׳s dysphoria factor in relation to MDD symptom dimensions of somatic and non-somatic psychopathology. 672 Ohio National Guard soldiers completed DSM-5 measures of PTSD and MDD symptoms in an epidemiological study. RESULTS: Results indicated that in contrast to other PTSD factors, PTSD׳s dysphoria factor was more related to MDD׳s somatic and non-somatic factors. LIMITATIONS: Limitations include generalizability to the epidemiological population of trauma-exposed military veterans rather than civilians, and reliance on self-report measures. CONCLUSIONS: Implications concerning clinical psychopathology and comorbidity of PTSD are discussed, including whether PTSD should be refined by removing its non-specific symptoms.