Suicidal ideation, behavior, and mortality in male and female US veterans with severe mental illness

We compared male and female American veterans with schizophrenia or bipolar disorder regarding clinical characteristics associated with lifetime suicidal ideation and behavior. Subsequent mortality, including death by suicide, was also assessed.

Data from questionnaires and face-to-face evaluations were collected during 2011-2014 from 8,049 male and 1,290 female veterans with schizophrenia or bipolar disorder. In addition to comparing male-female characteristics, Cox regression models-adjusted for demographic information, medical-psychiatric comorbidities, and self-reported suicidal ideation and behavior-were used to examine gender differences in associations of putative risk factors with suicide-specific and all-cause mortality during up to six years of follow-up.

Women overall were younger, more likely to report a history of suicidal behavior, less likely to be substance abusers, and had lower overall mortality during follow-up. Among women only, psychiatric comorbidity was paradoxically associated with lower all-cause mortality (hazard ratio [HR]=0.53, 95% CI, 0.29-0.96, p = 0.037 for 1 disorder vs. none; HR=0.44, 95% CI, 0.25-0.77, p = 0.004 for ≥2 disorders vs. none). Suicide-specific mortality involved relatively few events, but crude rates were an order of magnitude higher than in the U.S. general and overall veteran populations.

Incomplete cause-of-death information and low statistical power for male-female comparisons regarding mortality.

Female veterans with SMI differed from females in the general population by having a higher risk of suicide attempts. They also had more lifetime suicide attempts than male veterans with same diagnoses. These differences should inform public policy and clinical planning.