Post-traumatic stress disorder and drug use disorder : examination of aetiological models in a Swedish population-based cohort
Background: There are two primary phenotypic models of comorbidity between post-traumatic stress disorder (PTSD) and drug use disorder (DUD), i.e. self-medication (PTSD precedes and causes DUD) and susceptibility (DUD precedes and causes PTSD). We sought to clarify the longitudinal relationship between PTSD and DUD, while examining sex differences. Method: We used approximately 23 years of longitu