Clinical and treatment-related predictors of cognition in bipolar disorder: focus on visual paired associative learning

Bipolar disorder (BD) is associated with impairment in cognitive domains such as verbal memory and executive functions. However, visual paired associative learning (PAL) has been far less researched. Neurocognitive dysfunction in BD patients has been related to several clinical factors, but data on the effect of medication are relatively scarce and inconsistent. The aim of our study was to explore the effect of clinical and treatment-related parameters on executive functions and visual memory/learning, including PAL, in BD. Cognitive performance of 60 bipolar I patients and 30 healthy subjects was evaluated by using CANTAB battery tasks targeting spatial recognition memory, PAL and executive functions (set shifting, planning, inhibitory control). Bipolar patients showed poorer performance in PAL, set shifting, planning and inhibitory control than healthy subjects; however, only differences in PAL and planning survived correction for multiple comparisons. Number of previous manic episodes and illness duration predicted worse performance in set shifting and PAL, respectively, whereas current treatment with valproate predicted better performance in PAL. This is one of the first studies to assess clinical and treatment-related predictors of PAL in BD. We report a possibly beneficial effect of valproate on PAL, which warrants further investigation.