BACKGROUND: The current study was undertaken to examine whether posttraumatic stress symptoms (PTSS) and depressive symptoms mediated the association between trauma exposure (combat-related trauma and non-combat traumas occurring before, during, and after military service), and drug abuse symptoms use among male and female veterans. METHODS: Participants were 2304 (1851 male, 453 female) veterans who took part in a multi-site research study conducted through the Department of Veterans Affairs Mid-Atlantic Mental Illness Research, Education and Clinical Center (VISN 6 MIRECC). Path analytic models were used to determine the association between problematic past-year drug use and combat-related and non-combat trauma experienced before, during, or after the military and whether current post-traumatic stress symptoms or depressive symptoms mediated these associations. RESULTS: For both male and female veterans, depressive symptoms significantly mediated the effects of pre- and post-military trauma on drug abuse symptoms. CONCLUSION: Mental health providers who work with trauma-exposed Iraq and Afghanistan era veterans should assess for drug use, depressive symptoms, and life-span trauma (i.e., not only combat-related traumas) as part of a thorough trauma-based assessment for both men and women.