Neuropsychological functioning across different states of bipolar disorder: mania or hypomania and depression

Abstract

Aim of the studyThe aim of the study was to compare neuropsychological functioning across different states of bipolar disorder: mania/hypomania and depression.Subject or material and methodsCognitive functions were examined in 30 depressed bipolar patients aged 18-68 who fulfilled DSM-IV criteria for depressive episode (Hamilton Depression Rating Scale score ≥ 11) and 30 manic or hypomanic bipolar patients aged 23-68 who fulfilled DSM-IV criteria for manic or hypomanic episode (Young Mania Rating Scale ≥ 11). The comparison group consisted of 30 healthy subjects aged 23-71 without history of psychiatric or neurological disorders. A neuropsychological battery assessed executive functions and fluency (Wisconsin Card Sorting Test – WCST and Controlled Oral Word Association Test FAS, Stroop Color-Word Interference Test), working memory and attention (Trail Making Test Part B - TMT, N-back Test), psychomotor speed (TMT A) and reaction time (N-back Test).ResultsThe bipolar groups showed cognitive dysfunctions in working memory, fluency, attention, psychomotor speed and reaction time in relation to the comparison group. The manic/hypomanic group was also impaired on WCST, a measure of executive functions, which was not observed in depressive patients. Manic/hypomanic patients were significantly more impaired on executive functions than the depressed group.DiscussionThe obtained results are partly consistent with the previous results.ConclusionsA poorer neuropsychological performance was observed in different states of bipolar disorder but during manic/hypomanic state cognitive deficits were more serious regarding executive functions.