In an effort to study the efficacy of attracting and intervening with adult marijuana users, 290 men and 92 women were screened for participation in a treatment-outcome study focused on marijuana cessation. The well-educated, self-referred sample reported using marijuana on 79 of the past 90 days before testing. Indices of the severity of marijuana abuse and general psychopathology were in the clinical range for a majority of Ss. Ss who did not report evidence of alcohol or other drug abuse (n = 144) reported less severe consequences of marijuana use and experienced less general psychological distress than Ss who also reported lifetime (n = 165) or current abuse (n = 73) of other substances in addition to marijuana. The findings indicate the need for clinical research targeting adults who are dependent on marijuana.