Cognitive impairments in a clinical sample of recently diagnosed outpatients with bipolar disorder: The role of lifestyle, comorbidities, and psychotropic medications

BACKGROUND: It is unclear to which degree cognitive impairment in bipolar disorder (BD) are primary in origen or secondary to factors like subsyndromal symptoms, lifestyle, medication, and comorbidities, and/or a combination of both.

METHODS: Newly diagnosed individuals with BD underwent cognitive screening in a clinical setting with objective cognitive tests, mood ratings, and collection of self-reported cognition, medication, comorbidities, and lifestyle data. Associations between clinical and lifestyle factors and cognition were investigated with multiple linear regression. We also examined if individuals, who did not display any identified risk factors, exhibited cognitive impairment according to norm-based criteria.

RESULTS: In the 274 included individuals, more depressive symptoms and being unemployed was associated with poorer objective global cognition. Depressive symptoms correlated with cognitive complaints and objective impairments in all subdomains but verbal memory. Unemployment was associated with poorer verbal learning and memory. Higher BMI, drug use, and lower quetiapine dose each correlated with poorer verbal learning, working memory, and verbal memory, respectively. Fully remitted, employed patients (i.e., low risk of cognitive impairment)displayed lower scores on working memory and verbal memory than demographically adjusted norms, but better scores on verbal fluency, with 24 % showing global impairment.

CONCLUSIONS: Cognitive impairment was related to depressive symptoms and unemployment. For euthymic, employed patients, subtle cognitive impairments were also observed, indicating that they may represent a trait marker in BD. Future longitudinal studies should investigate causal mechanisms leading to cognitive deficits and multimodal lifestyle interventions to target both primary and secondary cognitive impairments in BD.