Adolescent marijuana use: risk factors and implications.

A sample of 1,270 students in Years 7, 10 and 11 attending seven State high schools in a middle class area of Sydney answered a self-report questionnaire designed to measure many aspects of their family situation, school performance, spare time activities, drinking and drug taking behaviour and sexual activity. Data on the reported prevalence of marijuana use and the variables significantly associated with marijuana use are presented and discussed. Marijuana use was reported by 4.2% of 12 year olds (Year 7), 26.5% of 15 year olds (Year 10) and 26.7% of 16 year olds (Year 11). More than half of those who had ever used marijuana had used it during the week prior to the survey and there were no significant differences in the characteristics between these recent and the remaining users. Marijuana users reported significantly poorer family relationships than non-users and were about twice as likely as non-users to come from a broken home and/or to have a mother who works full-time, which is often a consequence of marital break-up. Marijuana users also displayed poorer school performance, spent less time on homework and had more school absenteeism than non-users. Marijuana users were more than three times as likely as non-users to have had heterosexual intercourse, drunk alcohol 3 or more times in the past week and to smoke cigarettes. Also, the reported use of stimulants, hallucinogens, narcotics (heroin) and sedatives was almost entirely restricted to those who reported marijuana use. Improvements in the quality of family life may prevent the use of marijuana and other probably more harmful drugs, as well as the indulgence in other acting-out behaviours.