The paper examines the association between substance use and offender status and the association between substance use and recent criminal activity. The term "psychoactive substances" (or simply "substances") covers a range of chemicals that can have psychological effects and includes both licit (e.g., alcohol, glue) and illicit (e.g., cocaine, LSD) substances. The substances most frequently used by both young offenders and non-offenders were alcohol and marijuana. Alcohol appears to have a stronger direct association with acts of offending, most likely because of its strong disinhibiting properties. The article claims that needle use among youth was relatively common. In light of the risks of blood-borne diseases that can be transmitted by needle sharing, it states that intravenous drug use by young offenders should be a serious public health concern. The article recommends consideration of ways to more effectively restrict adolescents' access to alcohol. It also recommends evaluation of the efficacy of interventions to reduce substance misuse. Tables, figures, references