The most extensive and consistent evidence relates to young people’s interaction with their families. The key predictors of drug use are parental discipline, family cohesion, and parental monitoring. Categories where evidence linking specific factors is mixed include: mental health, Attention Deficit Hyperactivity Disorder (ADHD), stimulant therapy, religious involvement, sport, health educator interventions, school performance, early onset of substance use, and socioeconomic status. The overall ratio of risk to protection may be more important than any individual factor. The results, although supported by a relatively small body of research, support the concept of resilience to drug use. According to this view, resilience to drug use is enhanced by increasing social skills, social attachments and material resources despite constant exposure to known risk factors. There is substantial epidemiological literature on factors associated with increased risk of illicit drug use among young people. This report presents the results of a systematic review of the literature on factors associated with increased or decreased risk of drug use among young people. Table, references