The research was conducted formally and full-time between February 1984 and July 1985 and informally and periodically until February 1987. The researcher observed and participated in local community life, visiting homes, local pubs, community centers, meetings, and local groups. Interviews were conducted with public officials and health professionals. Informal contact was established with a large number of heroin users, and a smaller group of 20 addicts who used heroin daily were systematically observed. In the 1980's, there has been a rapid increase in 'chasing the dragon,' a method of ingesting heroin that involves inhaling it through a tube after it has been heated on tin foil. Findings suggest that, as with previous studies involving lower class heroin users, juvenile heroin use is an extension rather than a cause of delinquent behavior. Delinquency in North Southwark is a part of growing up in this community. Most grow out of their delinquency, but heroin use has had a radical effect on local delinquency patterns. The demands of supporting a long-term heroin habit have turned a hard core of delinquents into sophisticated adult thieves at an early age, often by 19 years old. A major preventive measure should be the continuous police harassment and prosecution of local fences; without them, the local heroin economy would collapse, because the youth who rely on theft to finance their heroin use would not be able to sell their stolen goods. 65 references.