ABSTRACT
Reviews of theories on adolescents’ substance use state that peer influences are the most consistent and strongest factor in the initiation and maintenance of substance use (Petraitis et al., 1995). The period of adolescence is characterised by an increase in time spent with peers, and young people have a strong need for social approval, group membership, and close friends (for example Hartup, 1996). Therefore, persons seem to be more susceptible to conforming to norms in their peer environment in the teenage years than in any other period (Finkenauer et al., 2002), which makes them vulnerable to initiate or maintain risky habits when they are in a context with substance using peers.
