Studies of early-adolescent drug use have revealed that friendship cliques that included drug-using peers resulted in either increased substance use within the clique over the course of a year, or breaking up of the clique (Kandel 1986). Observational studies of friendships revealed that a process of friendship support for drug use can be easily measured from videotaped friendship interactions and captured as a process of “deviancy training” (Dishion et al. 1995). Friends’ positive responses to drug use talk have been associated with increases in substance use in the next two years and when followed longitudinally into early adulthood (Dishion and Owen 2002).
