ADHD and comorbid disorders in relation to family environment and symptom severity

Background To examine the comorbidity of ADHD in association with family environment and the severity of ADHD. Method A screening for ADHD symptoms was conducted among adolescents in the Northern Finland 1986 Birth Cohort (N = 6622). A sample of those adolescents (n = 457), aged 16-18 years, with and without ADHD symptoms was assessed with a diagnostic interview (Kiddie-SADS-PL) and ADHD and comorbid disorders were studied in association with the family characteristics and the number of ADHD symptoms. Results Adolescents with ADHD had more commonly conduct disorder (P < 0.001), oppositional defiant disorder (P < 0.001), substance abuse (P < 0.001) and mild depression (P < 0.001) than adolescents without ADHD. Adolescents with ADHD and comorbid disorders had more ADHD symptoms (P < 0.001) than those with ADHD alone. Compared to adolescents with ADHD alone those with ADHD and comorbidity lived significantly more commonly in non-intact families, in low-income families, with mothers who were dissatisfied with life and with parents who showed little interest in their adolescents' activities. Conclusions Adolescents who develop externalizing disorders comorbid to ADHD seem to suffer from a severe form of ADHD and live in family environments that may not provide sufficient support for optimal development of an adolescent with ADHD.