Objective: This study evaluated mortality and causes of death over a seven-year period among middle-aged male psychiatric patients with and without co-occurring substance use disorder.
Methods: This cohort study examined mortality among 169,051 male Vietnam-era veterans ages 40 to 59 treated for psychiatric disorders by the U.S. Department of Veterans Affairs (VA) between April and September 1998. Demographic variables, diagnoses, and prior hospitalizations were obtained from VA electronic medical records. Mortality status was obtained from VA benefits records. Cause-of-death data were purchased from the National Death Index for a random sample of 3,383 decedents. Mortality among psychiatric patients with and without diagnosed co-occurring substance use disorders was compared by logistic regression, with controls for demographic factors, psychiatric and medical diagnoses, and prior hospitalizations. Causes of death for psychiatric patients with and without co-occurring disorders were compared by chi square analyses. Results were compared to age- and race-matched norms for the U.S. population.
Results: The risk-adjusted probability of dying was 55% higher among psychiatric patients with co-occurring substance use disorders than among those without substance use disorders (OR=1.58-1.69). Overdoses and substance abuse-linked illnesses accounted for 27.6% of deaths among psychiatric patients with co-occurring substance use disorders, compared with only 8.8% of deaths among other psychiatric patients.
Conclusions: Substance use disorders strongly contributed to premature death among male psychiatric patients. Secondary prevention is needed to reduce substance misuse and improve medical care for substance-related illnesses among psychiatric patients with co-occurring substance use disorders.