Abstract
Opinion statement
Cognitive impairment is a key feature of bipolar disorder (BD) which often persists into euthymia. This impairment appears to be independent, to an extent, of mood symptoms and is associated with deficits in overall functioning. Priority should thus be given to research investigating adjunctive treatments aimed at improving cognitive functioning in BD. This paper systematically reviews studies specifically examining changes in cognitive functioning in relation to pharmacological and/or psychosocial interventions in adults with BD. Eighteen studies were included in the review: 11 examining pharmacological interventions and seven examining psychosocial interventions. Findings from the reviewed studies were mixed but generally did not produce evidence of widespread cognitive improvement at treatment end in line with widespread cognitive impairment considered to be a key feature of BD. It is, however, difficult to draw conclusions from the research to date due to the general scarcity of studies in the area, small sample sizes, minimal replication of studies examining the same intervention and variability in study designs. Future research in the area would benefit greatly from investigating the current reviewed interventions in large-scale RCTs. An understanding of what particular subgroups of BD patients gain most benefit from cognitive interventions would be of clinical use.