Behavioral, psychosocial, and academic correlates of marijuana usage in adolescence. A study of a cohort under treatment.

In 1985 approximately 120,000 American high school seniors smoked marijuana daily. We interviewed 35 middle-class, cannabis-dependent adolescents with a mean age of 16 years who were patients in a drug treatment program. The patients also completed a lengthy self-assessment questionnaire designed to elicit information on drug-related problems. Our results show that family harmony, school attendance, and school achievement deteriorated once these young people began to use marijuana at least 4 days a week. The following behaviors were noted: remaining away from home without permission or parental knowledge for at least 7 consecutive days (29%), a D or F grade average on the last report card before they entered the drug treatment program (43%), involvement in a motor vehicle accident when the driver was under the influence of marijuana (26%), suicide attempts (20%), and convincing a "marijuana-naive" younger sibling to smoke the drug (20%). Despite such seemingly apparent signs of possible drug use by these 35 adolescents, a mean time of 12 months elapsed before parents suspected their children of marijuana abuse. In many cases mental health professionals consulted by a number of the children when they were using drugs were likewise unaware of the marijuana abuse.