The role of depression and suicidal cognitions as contributors to suicide risk among active duty soldiers reporting symptoms of posttraumatic stress disorder

Background: Military suicide rates have risen across all service branches, with the overall rate surpassing that of the general population for the first time in history in 2008. Service members with posttraumatic stress disorder (PTSD) are at a substantially higher risk for suicidal ideation, suicide attempts, and death by suicide than their peers without PTSD. While the link between PTSD and suicide is well established in the literature, less is known about the precise nature of that connection. Several constructs have been implicated as potential mediators of this relation, such as depression, alcohol use, suicidal cognitions, and sleep disturbance. Yet, to our knowledge, these constructs have never been examined simultaneously in a single model to determine mediational influence for suicide risk among soldiers with PTSD. Methods: A sample of 172 active duty Army soldiers completed a series of measures targeting the aforementioned constructs. Data were analyzed using mediation model analyses. Results: Suicidal cognitions fully mediated the relation between PTSD symptoms and current suicide risk severity. The indirect effect for suicidal cognitions was significantly larger than indirect effects for alcohol use, depression, and sleep disturbance. Exploratory analyses suggest serial mediation of the relation between PTSD and current suicide risk by depression and suicidal cognitions. Limitations: These results should be interpreted within the context of study limitations, to include use of self-report data and inability to firmly establish temporal sequencing assumed in mediation. Conclusions: Implications of this study include the improvement of suicide risk assessment and individualized treatment planning for suicidal military personnel with PTSD.