During a 2.5 yr follow-up of 263 addicts, suicidality was examined as a predictor of outcome & as an outcome to be predicted among initially nonsuicidal addicts. Suicidality predicted poor medical, psychosocial & substance abuse outcomes but fewer legal problems during follow-up. Among the 218 initially nonsuicidal, subsequent suicidality was not assoc. with a hist. of drug overdoses & psychosocial factors predictive of future suicidality differed from factors assoc. with a hist. of overdoses.