Social support as protective factor for suicidal ideation during treatment for substance abuse: Differential effects across treatment modalities

•Social support predicted odds of suicidal ideation (SI) in substance use patients.•Contact with one's social support system predicted lower mid-treatment SI in inpatients.•Interpersonal problems predicted odds of SI across both outpatients and inpatients.•Perceived performance in relationships predicted SI odds for both groups.•Relationship status had no effect on mid-treatment SI for either group.