AimsTo examine the association between a life-time history of insomnia and hypersomnia compared with no sleep disturbance and substance use patterns and amounts before and after a substance use treatment episode. DesignSecondary analysis of data from the Drug Abuse Treatment Outcome Studies conducted from 1991 to 1994. SettingData were collected at 96 substance use treatment programs in 11 United States cities, including short-term in-patient, long-term residential, methadone maintenance and out-patient drug-free treatment modalities. ParticipantsStudy samples included 7168 adults at treatment entry and 2965 at 12months post-treatment entry whose primary substance use at entry was alcohol (14.7%), cocaine (62.7%) or heroin (22.6%). MeasurementsLife-time history of insomnia and hypersomnia was assessed via self-report. Type and frequency of substance use were assessed at treatment entry. Substance use was also assessed 12months following treatment completion. Associations were examined using linear and logistic regression with age, sex, race, education level, depression history, treatment modality and in-treatment substance use as covariates. FindingsLife-time history of insomnia, hypersomnia, both or neither was reported by 26.3, 9.5, 28.0 and 36.2% of participants, respectively. Compared with no sleep disturbance, life-time insomnia and hypersomnia were associated at treatment entry with unique substance use patterns and a higher frequency of any substance use (P<0.001). All types of sleep disturbance were associated with higher rates of cocaine use at 12-month post-entry (odds ratios: 1.30-1.57). ConclusionsThere is evidence of an adverse association between substance use and sleep disturbance including higher frequency of all substance use before substance abuse treatment and higher rates of cocaine use after a treatment episode.