• bipolar disorder;
  • attention-deficit disorder;
  • comorbidity;
  • classification;
  • phenotype

Objective:  The occurrence of comorbid attention-deficit hyperactivity disorder (ADHD) might have an impact of the course of the bipolar disorder.

Method:  Patients with bipolar disorder (n = 159) underwent a comprehensive evaluation with respect to affective symptoms. Independent psychiatrists assessed childhood and current ADHD, and an interview with a parent was undertaken.

Results:  The prevalence of adult ADHD was 16%. An additional 12% met the criteria for childhood ADHD without meeting criteria for adult ADHD. Both these groups had significantly earlier onset of their first affective episode, more frequent affective episodes (except manic episodes), and more interpersonal violence than the bipolar patients without a history of ADHD.

Conclusion:  The fact that bipolar patients with a history of childhood ADHD have a different clinical outcome than the pure bipolar group, regardless of whether the ADHD symptoms remained in adulthood or not, suggests that it represent a distinct early-onset phenotype of bipolar disorder.