The associations between subjective and objective cognitive functioning across manic or hypomanic, depressed, and euthymic states in Chinese bipolar patients

Background: Patients may present cognitive deficits during all stages of bipolar disorder (BD). Few studies have examined self-reported cognitive difficulties and its relation to neurocognitive dysfunction during symptomatic periods of BD. This study aimed to compare subjective cognitive functioning and explore associations between subjective and objective cognitive functioning across different BD clinical states, and investigate the predicting and moderating roles of mood symptoms. Methods: Subjective cognitive functioning (measured by Cognitive Complaints in Bipolar Disorder Rating Assessment, COBRA) and several domains of cognitive functioning (assessed by a neuropsychological battery), including executive functions, attention and processing speed, and visual memory, were examined in 48 hypomanic or manic patients, 42 depressed bipolar patients, 50 euthymic bipolar patients and 60 healthy comparisons. Results: All patients exhibited subjective and objective cognitive deficits in relation to healthy comparisons. There was a significant association between subjective and objective cognitive functioning in euthymic group, but the association was not significant in acute symptomatic groups, which could be moderated by depressive or manic symptoms in depressive or manic group, respectively. Subjective cognitive functioning was significantly correlated with mood symptoms, and the best predictor of subjective cognitive functioning was depressive symptoms. Limitations: This was a cross-sectional study with a mixed sample of inpatients and outpatients. The medication effect was not adjusted. Conclusions: The associations between subjective and objective cognitive dysfunction varied in clinical states, and mood symptoms moderated the associations. A neuropsychological test battery is required to substantiate actual cognitive dysfunction in clinical settings, irrespective of subjective cognitive deficits.