The predictive role of daily cognitive stimulation on executive functions in bipolar disorder

This study aimed to estimate the predictive role of clinical and demographic variables on the three core executive functions (EF) - working memory (WM), inhibitory control (IC) and cognitive flexibility (CF) - in bipolar disorder (BD). The sample consisted of 38 patients with BD type I, 39 with BD type II, and 106 control participants with no mood disorders. Subjects completed the Hayling Test, Trail Making Test, Digit Span Backwards, Sentence Word Span Test, and Stroop Color-Word Test. Composite scores for WM, IC and CF were calculated, and their correlations with clinical and demographic variables were analyzed. Stepwise hierarchical regression models including all significant correlates, gender, and diagnosis, revealed that the frequency of reading and writing habits (FRWH), IQ and diagnosis predicted 38.1% of the variance in IC. Diagnosis and IQ predicted 24.9% of the variance in WM scores. CF was predicted by the FRWH only, which accounted for 7.6% of the variance in this construct. These results suggest that daily cognitive stimulation through reading and writing make a significant positive contribution to executive functioning in BD, even in the absence of continued education. These and other forms of routine cognitive stimulation should be further emphasized in intervention programs for BD.