Risk Factors for Natural Cause Mortality in a Cohort of 1494 Persons with Serious Mental Illness

Abstract Persons with serious mental illness die on average more than 10 years younger than those in the overall population, mostly due to natural causes. Previous studies have identified predictors of natural cause mortality in this population but few have been prospective studies using clinical variables from in-person evaluations. A cohort of 1494 individuals with schizophrenia, bipolar disorder, or major depressive disorder were assessed at baseline and mortality status was determined from the US National Death Index after up to 20 years of follow-up. Analyses included multivariate Cox proportional hazard models to determine independent predictors of natural cause mortality. A total of 125 (8.4%) individuals died of natural causes. In multivariate models, the strongest predictor of mortality after age was tobacco smoking at baseline with a dose-related effect. Having diabetes, a cardiovascular condition, particularly hypertension, and lower cognitive functioning were also significant risks, along with divorced/separated status. The receipt of gabapentin or fluoxetine also significantly increased mortality risk. Premature death can be reduced by smoking cessation and the improved management of conditions such as hypertension and diabetes.