Association of childhood externalizing, internalizing, comorbid problems with criminal convictions by early adulthood

Childhood externalizing problems have been linked with adult criminality. However, little is known about criminal outcomes among children with comorbid externalizing and internalizing problems. We examined the associations between profiles of behavioral problems during childhood (i.e., externalizing, internalizing, and comorbid) and criminality by early adulthood. Participants were N = 3017 children from the population-based Quebec Longitudinal Study of Kindergarten Children followed up from age 6–25. Multitrajectory modelling of teacher-rated externalizing and internalizing problems from age 6–12 years identified four distinct profiles: no/low, externalizing, internalizing, and comorbid problems. Juvenile (age 13–17) and adult (age 18–25) criminal convictions were extracted from official records. Compared to children in the no/low profile, those in the externalizing and comorbid profiles were at higher risk of having a criminal conviction, while no association was found for children in the internalizing profile. Children with comorbid externalizing and internalizing problems were most at risk of having a criminal conviction by adulthood, with a significantly higher risk when compared to children with externalizing or internalizing problems only. Similar results were found when violent and non-violent crimes were investigated separately. Specific interventions targeting early comorbid behavioral problems could reduce long-term criminality.