Relationship of PTSD, Alcohol Use Disorder, and Combat Experiences to Suicide in Veterans

Background: There is a high rate of suicide among veterans—with some estimates indicating 20 or more completed suicides per day. Although research has documented a number of precipitants of suicide, one area that has been understudied is the risk associated with Posttraumatic Stress Disorder (PTSD) and alcohol use disorder (AUD). Given the high rate of PTSD and AUD in veterans, and the frequency with which these problems co-occur, exploring potential pathways by which PTSD and AUD contribute to suicidality has the potential to inform clinical intervention and prevention efforts.

This study is guided by the Transpersonal Theory of Suicide, which suggests that thwarted belongingness and perceived burdensomeness are two essential preconditions for suicidal behavior. Previous research has suggested that both PTSD and AUD have social consequences and are chronic and relapsing conditions, which aligns with the definition of perceived burdensomeness. Secondly, research has also suggested that veterans may feel isolated as a function of their combat experiences, which aligns with the definition of thwarted belongingness.

This study hypothesized that PTSD and AUD would have direct, positive effects on suicide and that combat experiences would have direct effects on PTSD and AUD. Furthermore, this study hypothesized that combat experiences would have indirect effect on suicide through both PTSD and AUD.

Methods: Veterans (n=396) completed the Posttraumatic Stress Disorder Checklist (PCL-5), the Alcohol Use Disorder Identification Test (AUDIT), and Combat Experiences Scale (CES). Suicidality was assessed with three to six questions. Participants were first asked if they had a lifetime history of suicidal thoughts, plans, and attempts. Participants who responded yes to any of the questions were prompted to report if the thoughts, plans, and attempts occurred in the past year.

Participants were provided with a list of mental health and medical resources at the beginning and end of the study. Our university’s Institutional Review Board approved study protocol.

A bootstrap with 5000 random draws was used to test the indirect effect of combat experiences on suicide after the model was fitted to the data.

Results: Participants endorsed an average of 2.76 (sd=1.88) items on the suicide questions. Mean scores on the PCL-5 were 38.38 (sd=8.69); mean scores on the AUDIT were 18.16 (sd=5.43); mean scores on the CES were 23.75 (sd=6.83).

The hypothesized path model fit the data well; fit statistics met established thresholds (CFI=.95; TLI=.90; c²=102.96; p=n.s.). All individual path coefficients were in the hypothesized direction and statistically significant. The indirect effect of CES on suicide was also significant through both pathways, however the effect was much stronger via the AUDIT pathway than via the PCL-5 pathway. The effects survived the bootstrap.

Implications: Consistent with the Transpersonal Theory of Suicide, this analysis suggests that combat experiences, AUD, and PCL are risk factors for suicide in veterans because they overlap with the dimensions of thwarted belongingness and perceived burdensomeness. Since clinical attention can modify these variables, PTSD and AUD treatment may also reduce risk for suicide. Future research must identify other mediators on these pathways to increase intervention targets.