A Bad Start: The Combined Effects of Early Onset Substance Use and ADHD and CD on Criminality Patterns, Substance Abuse and Psychiatric Comorbidity among Young Violent Offenders.

Substance abuse, conduct disorder (CD) and attention deficit/hyperactivity disorder (ADHD) are all known risk factors for developing aggressive behaviors, criminality, other psychiatric comorbidity and substance use disorders (SUD). Since early age of onset is important for aggravating the impact of several of these risk factors, the aim of the present study was to investigate whether young adult violent offenders with different patterns of early onset externalizing problems (here: substance use < age 15, ADHD, CD) had resulted in different criminality profiles, substance use problem profiles and psychiatric comorbidity in young adult age. A mixed-method approach was used, combining a variable-oriented approach (with Kruskal Wallis tests) and a person-oriented approach (with Configural frequency analysis). Overall, this combined approach indicated that persons with combined ADHD+CD and persons with CD + early onset of substance use had a more varied history of violent crimes, a more comprehensive history of aggressive behaviors in general, and more psychiatric comorbidity, as well as more varied SUD and destructive substance abuse in adult age, than persons without ADHD, CD or early SU. Results are in line with previous variable-oriented research, but also indicate that individuals in this group with heavy problem aggregation early in life have a wider spectrum of problems in young adult age. Importantly, among these young violent offenders, problem aggregation was the overwhelming norm, and not the exception, as in studies of the general population. This emphasizes the need for early coordinated interventions, but also that treatment within correctional facilities in adult age needs to be comprehensive and take individual patterns of comorbidity into account.