The 1,353 subjects in this group (25.1% of the total sample) were the heaviest substance users, and were significantly affected by their opioid use: 75.1% reported arrests or trouble with police due to opioid use, significantly higher than all other groups. Subjects reported both the earliest onset of opioid use [mean age (SD)=18.9 (4.2)] and the heaviest use [mean (SD)=25.4 (7.0)]. They also had the highest prevalence of other substance dependence except CD and alcohol dependence and psychiatric disorders except panic disorder.
