University of Groningen The development of depression in children and adolescents with ADHD

Objectives: The progression to depression in children with Attention Deficit Hyperactivity Disorder (ADHD) is not clearly understood. To clarify this relationship we tested the following hypotheses in a population based study: 1) Children with ADHD have a higher risk of developing depression than children without ADHD; 2) The pathway from ADHD to depression is mediated (partly) through anxiety and disruptive behaviour disorders; and 3) Mediation through anxiety is more prevalent in girls and mediation through disruptive behaviour disorders is more prevalent in boys. Method: From October 2008 to September 2010, The Composite International Diagnostic Interview (CIDI) was used to assess ADHD, Major Depressive Episodes (MDE), anxiety disorders and disruptive behaviour disorders in 1584 participants from the TRacking Adolescents’ Individual Lives Survey (TRAILS) cohort. Cox regression was used to model the effects of ADHD, anxiety and disruptive behaviours on depression. Risk of, and pathways to depression were studied in both children with ADHD and children with subthreshold ADHD. Results: Comorbid depression was present in 36% of children with a diagnosis of ADHD, 24% of children with subthreshold ADHD and 14% of children with no ADHD. Anxiety and disruptive behaviours mediated 32% of depression in ADHD. Pathways through anxiety and disruptive behaviour disorders were independent of gender. Disruptive behaviour disorder was a stronger mediator than anxiety for both genders (all p < .01). Conclusion: These findings may help forewarn about impending depression and therefore allow opportunities for interventions when either comorbid anxiety and/or disruptive behaviour disorders are present in a child with ADHD.