Cognitive impairment in euthymic patients with bipolar disorder: Prevalence estimation and model selection for...

Objectives Although cognitive dysfunction is a prominent feature of bipolar disorder (BD), previous research presents limitations in estimating the proportion of euthymic patients experiencing clinically relevant deficits and identifying predictors of cognitive difficulties. We explored the relevance of recommended definitions of clinically significant cognitive impairment for functional outcomes, estimated its prevalence, and identified patient characteristics associated with cognition. Methods We assessed cognitive performance across four domains in 80 euthymic participants with BD. Participants were categorized based on two criteria for clinically significant cognitive impairment and we assessed the ability of these criteria to differentiate participant performance on established functional outcomes. Variable selection with elastic net regression was used to identify sociodemographic and clinical factors associated with cognitive performance. Selected variables were examined as predictors of clinically significant cognitive impairment with logistic regression. Results According to the selected criterion, 34% presented with clinically significant cognitive impairment. Poorer current cognitive performance was associated with older age, lower estimated premorbid IQ, more currently prescribed psychotropic medications, fewer previous psychological therapies, and current use of antipsychotics. A model with premorbid IQ, psychotropic medications and previous psychological therapies as predictors of cognitive impairment correctly classified 75% of the participants. Conclusions This is one of the first studies to use a model selection approach to identify factors associated with cognitive difficulties in BD. Our findings offer the initial steps towards a predictive model for cognitive impairment. This could improve treatment decisions and prioritization for euthymic patients with BD, particularly the implementation of cognitive interventions.