An epidemiological study of ADHD and conduct disorder: does family conflict moderate the association?

PURPOSE: To examine the role of family conflict in the relationship between attention deficit hyperactivity disorder (ADHD) and conduct disorder (CD).

METHODS: A cross-sectional national population survey was carried out among 10,838 14-16 year old students in all secondary schools in Iceland. Three latent measures, financial status, ADHD and CD, and one observed measure, family structure, were included in the study. A structural equation model was used to evaluate direct effects between ADHD and CD for four different groups; females and males, experiencing family conflict and those not experiencing family conflict.

RESULTS: ADHD was significantly and positively associated with CD for all groups. When controlling for financial status and family structure it was found that ADHD was positively and significantly associated with CD for adolescent females and males not experiencing family conflict as well as for those experiencing family conflict. The link between ADHD and CD was significantly stronger for those adolescents who had experienced family conflict compared to those who had not experienced family conflict. These results suggest that family conflict moderates the association between ADHD and CD for both girls and boys.

CONCLUSIONS: The results of this study indicate that family environment and ADHD symptoms are important when predicting CD among adolescent youth. Most notably, family conflict exacerbates the effects of ADHD symptoms on CD among both females and males.