The report covers five consecutive surveys conducted in 1987, 1990, 1994, 1997, and 2001 by the Centre for Drug Research of licit and illicit drug users over the age of 12. The population was selected randomly from 3,000-4,000 people in the Amsterdam Population registry. Drug use prevalence is described by three prevalenc indicators: use during lifetime, during the last year, and during the last 30 days. The types of drugs covered include tobacco, alcohol, cannabis, hypnotics, sedatives, cocaine, amphetamines, ecstacy, heroin, hallucinogens, opiates, mushrooms, inhalants and performance enhancing drugs.