Social connection and suicidal thoughts and behaviors in the Million Veteran Program cohort

People with lower levels of social connection are at increased risk for suicidal thoughts and behaviors. This extends to populations at greater risk of death by suicide, including U.S. military veterans. Despite this well-established association, it is unclear which measures of social connection are most useful in identifying veterans who could benefit from intervention to prevent suicide. To this end, we used data from the Million Veteran Program (MVP) to investigate the measures of social connection most strongly associated with suicidal thoughts and behaviors. Our sample included 264,626 veterans who reported on three measures of social connection-marital status, household size, and perceived social support-and were assessed for suicidal thoughts and behaviors using electronic health records. Veterans who were partnered (OR = 0.78, 95% CI [0.76-0.80], p < .001), living with others (OR = 0.71, 95% CI [0.70-0.73], p < .001), or reported higher levels of social support (OR = 0.67, 95% CI [0.65-0.69], p < .001), were less likely to have suicidal thoughts and behaviors. These associations varied by veterans' age, sex, and era of military service. When combined into a single risk score, lower levels of social connection were associated with greater likelihood of suicidal thoughts and behaviors (β = 1.42, 95% CI [1.40-1.43], p < .001). Social support, particularly positive social interactions, showed the strongest associations with suicidal thoughts and behaviors in elastic net regression models. Common measures of social connection, particularly social support, could be useful in assessing suicide risk and treatment needs for veterans.