General population suvery data are used to disaggregate the associations of substance use disorders with suicide attempts in order to evaluate a number of hypotheses about the processes leading to these assocations. Data are from the US National Comorbidity Survey (1990–1992). Discrete-time survival analysis is used to study theeffects of retrospectively reported temporally prior substance use, abuse, and dependence in predicting first onset of suicidal behavior. Alcohol and drug use predict subsequent suicide attempts after controlling for sociodemographics and comorbid mental disorders. Previous use in not a significant predictor among current nonusers. Abuse and dependence ar esignificant predictors among users for three of the 10 substances considered (alcohol, inhalants, and heroin). The number of substnaces used is more important than the types of substances used in predicting suicide behavior. Disaggregation shows that the effects of use are largely on suicidal ideation and onon planned attempts among ideators. In comparison, the effects of use on suicide plans and planned attempts among ideatros are not significant. Clinical need to be aware that current substance use, even in the absence of abuse or dependence, is significant risk factor for unplanned suicide attempts among ideatos. An J Epidemiol 2000;151:781–9.