Posttraumatic stress disorder, depression, and non-fatal intentional self-harm in Massachusetts Veterans

BACKGROUND The literature on the association between Posttraumatic Stress Disorder (PTSD) and fatal and non-fatal intentional self-harm (ISH) among Veterans who receive care within the Veterans Health Administration (VHA) is limited in scope and contradictory. The current study examines the association between PTSD and non-fatal ISH in a gender-stratified sample of patients who received care at a Massachusetts VHA treatment facility between 2000 and 2008. METHODS VHA electronic medical record data were obtained for patients who received a PTSD diagnosis at a Massachusetts treatment facility (n = 16,004) and a gender/age matched comparison group (n = 52,502). Rate ratios for the association between PTSD and non-fatal ISH were computed adjusting for marital status, depression, alcohol or drug abuse or dependence, anxiety disorder diagnoses and prior ISH and clustering by hospital using Poisson regression. The interaction between PTSD and depression diagnoses in predicting non-fatal ISH was assessed as the departure from additive effects by calculating the interaction contrast (IC) while adjusting for identified confounders. RESULTS Over the eight year study period 146 (0.91%) of those with PTSD experienced non-fatal ISH, while 71 (0.14%) of those without PTSD experienced non-fatal ISH. Strong adjusted associations between PTSD and non-fatal ISH were found for both male (RR = 3.3, 95% CI = 2.3, 4.6) and female (RR = 16, 95% CI = 4.7, 55) VHA patients. Evidence of an interaction between PTSD and depression diagnoses in predicting non-fatal ISH was found as a departure from additive effects for both sexes, but this association was more marked among women than among men. CONCLUSIONS Our results indicate that non-fatal ISH among women may be more strongly related to PTSD than prior work focusing on suicide has suggested and highlight the importance of gender-stratified examinations of these associations. Further, our results suggest that suicide prevention approaches in the VHA should integrate treatment for PTSD and depression.