Psychiatric diagnoses and criminal convictions in youth: A population-based study of comorbidities of diagnoses

Psychiatric diagnoses are important risk factors for criminal convictions, but few longitudinal studies have examined comorbidity patterns in relation to youth criminal convictions. To explore associations between specific psychiatric diagnoses (substance use disorder (SUD), ADHD, depression, PTSD, intellectual disabilities (ID), and autism spectrum disorders (ASD)) and comorbidities of internalizing, externalizing, or neurodevelopmental diagnoses (NDD) in relation to risk of non-violent or violent criminal convictions in youth, including potential sex differences. Data on 1,411,538 individuals born in Sweden (1985–1998) were obtained from national population-based registers. Exposure was psychiatric diagnoses and outcome was criminal convictions between ages 15 and 20. 17% of individuals had a psychiatric diagnosis, of whom 20% were convicted of a crime. All diagnoses, except ID and ASD, increased the risk of non-violent and violent crimes. Comorbidities of externalizing and internalizing diagnoses heightened the risk compared to single diagnoses. NDD increased the risk among SUD, depression, and PTSD, while NDD comorbid with another NDD decreased the risk for criminal convictions. Of the three comorbidity categories, externalizing disorders heightened risk the most, followed by internalizing disorders. This study highlights specific risk patterns for criminal convictions related to comorbidities, and to crime type and sex. •There are different risk patterns for criminal convictions related to comorbidities of psychiatric diagnoses.•Comorbidities of externalizing diagnoses are strongly related to violent criminal convictions in youth.•Comorbidities of internalizing diagnoses are related to criminal convictions in youth.•Consideration should be taken to type of crime and sex in these associations.•Neurodevelopmental disorders are differently related to criminal convictions compared to other diagnoses.