Convictions among adolescents and young adults in Swedish substance use treatment: A latent class analysis

There is a long-standing international research interest in how substance use and criminality are intertwined. Research on adolescents in substance use treatment has observed high rates of criminality, but little is known in the international literature about how different types of criminality are patterned among patients. The aim of this study was to identify different criminal profiles, in terms of convictions, among adolescents and young adults in Swedish substance use treatment.

The sample included all patients aged 13 to 25 who were in contact with Sweden's largest specialized regional provider of substance use treatment for adolescents and young adults, Maria Ungdom (MU) Stockholm, between 2011 and 2021 (n = 29,960). Data on convictions were gathered from the Swedish National Conviction Register and linked to data from patient journals and other Swedish registers. Latent class analysis was used to identify different subgroups based on 12 different offenses. Differences between these sub-groups on socio-demographic and clinical characteristics were also explored.

Over 40% of the patients had been convicted between 2011 and 2021, with drug offenses being the most common. The LCA identified six classes based on offenses included in the convictions, including classes defined by single offense types to a class characterized by multiple offenses. The largest class (47.8%) consisted of patients with primarily drug offenses and the smallest class consisted of patients primarily defined by shoplifting (6.5%). Comprising only about 5% of all patients, the class with multiple offenses accounted for 32.8% of all convictions. Classes differed across socio-demographic and clinical variables, where the class with multiple offenses was the most severe. Patients with no convictions scored more favorably on socio-demographic and clinical variables compared to those who had been convicted.

A large share of adolescents and young adults in substance use treatment have been convicted for criminal offenses. However, there is profound heterogeneity in this group related to type of offenses as well as to socio-demographic and clinical characteristics. This heterogeneity should be considered in further research and in the provision of treatment.