Changes in drug behavior from the middle to the late twenties: initiation, persistence, and cessation of use.

Patterns of initiation, persistence, and cessation of use of licit, illicit, and prescribed drugs are presented for a longitudinal cohort from their middle to the late twenties. The cohort is representative of adolescents formerly enrolled in public secondary high schools in New York State. No additional initiation of cigarettes, alcohol, and illicit drugs occurred in the four-year follow-up interval, except for cocaine and pills. The largest proportional increase of new users occurred for prescribed psychoactive drugs. Alcohol showed the most persistence of use, followed by cigarettes and marijuana. As the cohort ages, those who continue to use illicit drugs actively do so at lower levels of intensity than at younger ages. For each drug class, the persistence of use is strongly related to earlier intensity of involvement. By age 29, men have accumulated almost twice as many months of use of illicit drugs as women.