Postdeployment suicidal ideations and trajectories of posttraumatic stress disorder in Danish soldiers: a 3-year follow-up of the USPER study

OBJECTIVE: Suicidal ideation in veterans is of great concern. The objective of this study is to examine how heterogeneous posttraumatic stress disorder (PTSD) trajectories are associated with postdeployment suicidal ideation in veterans 2.5 years postdeployment to a combat zone in Afghanistan. If PTSD trajectories are associated with postdeployment suicidal ideations, then the accumulative knowledge on what characterizes veterans falling into different PTSD trajectories may provide better opportunities for early identification of suicidal high-risk veterans.

METHOD: In this prospective study of 743 Danish soldiers deployed to Afghanistan from February to August in 2009, we collected data at 6 time points from 6 weeks before deployment to 2.5 years after homecoming (total for this study: 456). At all assessments, the soldiers responded to a comprehensive questionnaire including measures of PTSD (measured by the PTSD Checklist, Civilian Version) and other mental and physical health variables, demographics, and social and combat-related factors. Suicidal ideation was measured by an item from the European Parasuicide Study Interview Schedule II. In a previous study based on soldiers from this cohort, we identified 6 PTSD trajectories using latent growth mixture modeling, which we have extracted and applied as independent variables in this study. Adjusted multivariable logistic regression analyses were applied to examine whether deployed soldiers with certain PTSD symptom trajectories were more likely to report suicidal ideation 2.5 years after homecoming.

RESULTS: Two PTSD trajectories with high PTSD symptom level 2.5 years after return were significantly associated with suicidal ideation 2.5 years after homecoming. Thus, a relieved-worsening class, described by initial decreasing PTSD symptom levels followed by a steep increase in symptoms had higher risk of suicidal ideation (OR = 7.84; 95% CI, 1.68-36.6), which was also the case for a late-onset class (OR 5.2; 95% CI, 2.21-12.24) when compared to a low-stable class.

CONCLUSIONS: Heterogeneous PTSD trajectories are associated with suicidal ideation in veterans 2.5 years after homecoming.