Associations between cognitive impairment and quality of life in euthymic bipolar patients

During the euthymic state in bipolar disorder, cognitive functions often remain affected. Specifically, subjective and objective cognitive impairment might distinctly affect patients' quality of life (QoL); however, this question had not been examined previously in Japanese patients. Therefore, the current study investigated the associations between cognitive complaints, QoL, and objective cognitive functions. Forty patients in remission were recruited from the Hokkaido University Hospital, Sapporo, Japan and assessed with the translated version of the cognitive complaints in bipolar disorder rating assessment (COBRA), medical outcomes study 36-item short-form health survey version 2 (SF-36v2), and Sheehan disability scale (SDS). The Japanese adult reading scale, Wisconsin card sorting test, word fluency, continuous performance test, trail making test (TMT), auditory verbal learning, and Stroop test evaluated objective cognitive functions. Significant correlations were observed between the COBRA, SF-36v2, and SDS results, as well as the TMT scores. Overall, euthymic patients were aware of their cognitive dysfunction, which could be understood in relation to the decrease in satisfaction in their daily life. Therefore, even mild cognitive impairments can have ramifications for patients in the euthymic state of bipolar disorder.