The risk for first-onset major depression, anxiety, and substance use disorders associated with prior posttraumatic stress disorder (PTSD) was estimated in a sample of women.
The National Institute of Mental Health Diagnostic Interview Schedule, revised according to DSMIII-R, was used to measure lifetime psychiatric disorders in a stratified random sample of 801 mothers of children, who participated in a study of cognitive and psychiatric outcomes by level of birth weight. Cox proportional hazards models with time-dependent covariates were used to calculate the hazards ratios of first onset of other disorders following PTSD.
The lifetime prevalence of traumatic events was 40% and of PTSD, 13.8%. Posttraumatic stress disorder signaled increased risks for first-onset major depression (hazards ratio, 2.1) and alcohol use disorder (hazards ratio, 3.0). The risk for major depression following PTSD was of the same magnitude as the risk for major depression following other anxiety disorders. Women with preexisting anxiety and PTSD had significantly increased risk for first-onset major depression. Additional analysis showed that preexisting major depression increased women's vulnerability to the PTSD-inducing effects of traumatic events and risk for exposure to traumatic events.
Posttraumatic stress disorder influences the risk for first-onset major depression and alcohol use disorder. The causal explanation of these temporally secondary disorders is unclear and might involve the effect of PTSD or underlying vulnerabilities exposed by the traumatic experience.