Comorbidity of attention deficit hyperactivity disorder in adult bipolar I disorder: a preliminary study

Objective: Attention-deficit hyperactivity disorder (ADHD) is a disorder that typically first appears in childhood and has the main symptoms of inattention, overactivity, and impulsivity. Attention-deficit hyperactivity disorder and bipolar disorder are frequently comorbid and overlapping diagnoses. Although there is data describing the overlap of ADHD and bipolar disorder in childhood and youth, little is known about the comorbidity of these disorders in adulthood. In this study, our aim was to investigate comorbidity of attention deficit hyperactivity disorder in bipolar disorder and to compare several socio-demographic and clinical variables of bipolar patients with and without comorbid ADHD. Method: Sixty patients diagnosed with euthymic bipolar I disorder were enrolled in the study. Patients with bipolar disorder were observed in the outpatient setting during at least two months to ensure the existence of euthymia before the study procedures were conducted. Socio-demographic data form, Hamilton Depression, Young Mania, Wender Utah and Adult ADHD Rating Scales, and the Structured Clinical Interview for DSM-IV were applied to the participants. Socio-demographic data included variables such as age, gender, educational status, episode number, and the type of present treatment. Between group comparisons were made by using Mann-Whitney U test and Chi-square test. Results: The comorbidity rate of ADHD in our study sample with bipolar I disorder was 21.7%. There were no significant differences between with and without comorbid ADHD groups in terms of their age, gender, and educational level. Comorbid ADHD patients were smoking more cigarettes than those without comorbid ADHD. In addition, the number of their total episodes and manic episodes were relatively higher in the comorbid ADHD group. Conclusions: The results suggest that ADHD is a common comorbidity in adult bipolar patients. The existence of high rates of comorbidity leads to important diagnostic and therapeutic complications. Further study is needed to clarify the impact of ADHD on clinical outcomes of adult bipolar patients and to provide guidelines for therapeutic approaches.