A neuropsychological comparison of bipolar disorder and adult attention deficit hyperactivity disorder

Abstract

Aim: The present study aimed to compare cognitive signs of bipolar disorder patients with that of adult attention-deficit/hyperactivity disorder (ADHD) patients. Method: The study comprised 66 bipolar disorder patients, 63 ADHD patients, and 58 healthy controls.Structured Clinical Interview for DSM-IV Axis-I Disorders (SCID-I), Wender Utah Rating Scale, and Adult Attention-Deficit/Hyperactivity Rating Scale were performed in all subjects, whereas bipolar disorder patients underwent additional Hamilton Depression Rating Scale and Young Mania Rating Scale. Subsequently, all participants underwent cognitive assessment including Digit Ordering Test, Verbal Memory Process Test, Wisconsin Card Sorting Test and Stroop Test. Results: Bipolar disorder, ADHD and control groups did not differ significantly from each other with regard to age, sex and duration of education. Bipolar patients displayed poorer performance in Digit Span Test, Verbal Memory Process Test, Wisconsin Card Sorting Test and Stroop Test as compared to the control group. ADHD patients were worse than the control subjects in Stroop Test (subtest of difference in times). Bipolar disorder patients were poorer than ADHD patients in cognitive tests except for Stroop Test. Conclusion: In general, bipolar disorder patients have much more severe cognitive impairment than ADHD patients in terms of verbal memory and executive functions. The results supports the idea of bipolar disorder and ADHD are different, at least in terms of cognitive performance.