Violent, nonviolent, and substance-related offending over the life course in a cohort of males and females treated for substance misuse as youths.

Most studies on adolescent offending heterogeneity are based on general population samples, and few include individuals with substance misuse or look specifically at substance-related offending. It is also unclear how offender subtypes develop after young adulthood or how offending heterogeneity varies between genders. This study aimed to identify subgroups of offending among adolescents with misuse problems and to examine associations with offending in adulthood. The study included 1,992 females and males that consulted a clinic for adolescents with misuse problems between 1968 and 1971. Latent Class Analyses were conducted to identify subgroups based on violent and nonviolent offending before age 20. Participants were then followed until age 50 and reexamined regarding violent, nonviolent, and substance-related crimes. Associations between subgroups before age 20 and subgroups age 21-50 were examined. Before age 20, three subgroups were identified among the females and six among the males. Males were more specialized in their offending and demonstrated higher levels of offending. Results pointed to both stability and decrease of violent and nonviolent offending, and to the emergence of substance-related offending in adulthood in both genders. The connection between substance-related crimes and general delinquency in adulthood among individuals treated for substance misuse suggests that interventions should also address substance misuse for reducing the overall volume of crime. This study also highlights the importance of including females in research on offending heterogeneity.