Background. Sociological studies have shown that poor social integration confers suicide risk. It is not known whether poor integration amplifies risk after adjusting statistically for the effects of mental disorders and employment status.

Method. A case-control design was used to compare 86 suicides and 86 living controls 50 years of age and older, matched on age, gender, race, and county of residence. Structured interviews were conducted with proxy respondents for suicides and controls. Social integration was defined in reference to two broad levels of analysis: family (e.g. sibship status, childrearing status) and social/community (e.g. social interaction, religious participation, community involvement).

Results. Bivariate analyses showed that suicides were less likely to be married, have children, or live with family. They were less likely to engage in religious practice or community activities and they had lower levels of social interaction. A trimmed logistic regression model showed that marital status, social interaction and religious involvement were all associated with suicide even after statistical adjusting for the effects of affective disorder and employment status. Adding substance abuse to the model eliminated the effects of religious involvement.

Conclusions. The association between family and social/community indicators of poor social integration and suicide is robust and largely independent of the presence of mental disorders. Findings could be used to enhance screening instruments and identify problem behaviors, such as low levels of social interaction, which could be targeted for intervention.