Delinquency and substance use are more likely to co-occur in adolescence compared to earlier and later developmental periods. The present study examined developmental pathways to co-occurring problem behavior from 6th-10th grade (N=2,002), testing how peer delinquency and substance use were linked to transitioning between abstaining, delinquency, substance use, and co-occurring problem behavior. Developmentally, most youth transition from abstinence to delinquent behavior, and then escalate to co-occurring problem behavior. Once co-occurring problem behavior onsets, remitting to single problem behavior or abstinence is unlikely. The impact of peers on problem behavior are domain specific when individuals transition from abstaining to a single problem behavior, but are more general with respect to escalation of and desistance from problem behavior.
Keywords: delinquency; developmental psychopathology; peer group; substance use.