In a number of studies in Metropolitan Chicago, Hughes and the University of Chicago group1-3 have found that heroin addiction occurs in epidemics, that heroin use spreads from peer to peer, and that newly involved cases are much more "contagious" than are chronic cases. Microepidemics— 5 to 15 new cases over a five-year period—are seen in some locales, and macroepidemics—more than 50 new cases over a five-year period—in others. Hughes et al believe that macroepidemics are most likely in areas of high unemployment and crime, deterioration in housing, poor or absent neighborhood leadership, a large recent influx of povertylevel persons, and the many other expressions of urban blight. Their observations parallel those of Leighton et al,4 who found a strong positive correlation between social disorganization and a wide range of behavior disorders.
Exploratory work carried out by the Illinois Drug Abuse Program, a cooperative venture sponsored by the