Four types of drug abusers were identified. The "addicted criminals" apparently resembled the groups dominant in Sweden from the 1950s to the 1970s. An early crime debut and criminal offenses in youthful years characterized their deviant careers. Drugs and criminal activities coexisted with an often very high intake of alcohol and the most difficult childhood and adolescence conditions compared to other types. The "criminal addicts" had fewer recorded acts of juvenile delinquency. Their drug abuse was severe and occurred later in life, as did criminality, but tended to accelerate rapidly. Their subcultural affiliation was probably as strong as that of the addicted criminals. A large group called "low-crime addicts" had a weak subgroup affiliation. The "normal" abuse pattern, with cannabis as the first substance used and a gradual shift to more severe opioid and central-nervous-system stimulant abuse, was most true of this type. The drug abuse probably played a role in the development of the criminal pattern. "Emotionally unstable addicts with little or no criminality" had the best education, job situation, and social relations. Multiple drug abuse and abuse of legal drugs were common. Mental ill-health was characteristic for this group. The results show that drug abusers in Sweden cannot be viewed as a homogeneous group of individuals, that they do not commit crimes only in order to finance their habit, and that the history of narcotics use in Sweden, with its strong connection to a criminal subculture, is highly relevant to this sample. 6 tables and 33 references