Cognitive complaints in individuals recently diagnosed with bipolar disorder: A cross-sectional study

To assess the differences in subjective cognitive dysfunction between major depressive disorder (MDD) and recently diagnosed Bipolar Disorder (BD) across euthymia and mood episodes.

This is a cross-sectional study corresponding to the second wave of a longitudinal study. The first wave consisted of subjects aged between 18 and 60 diagnosed with MDD. In the follow up after three years (second wave), conversion from MDD to BD diagnosis was assessed by qualified psychologists using the Mini International Neuropsychiatric Interview (MINI-Plus). Subjects were categorized in four diagnostic groups: euthymic MDD, MDD in a current mood episode, euthymic BD, and BD in a current mood episode. All subjects completed the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA), an instrument specifically designed for detecting subjective cognitive deficits in BD.

The total sample (n = 468) included 410 subjects with MDD and 58 individuals recently diagnosed with BD. We subdivided the 2 groups based on their current mood state, and found a significant difference in COBRA total scores between euthymic BD individuals (median 17.00 [IQR: 8.75 - 20.75]) and euthymic MDD subjects (median 8.00 [IRQ: 5.00 - 14.00], p = 0.002), showing higher subjective cognitive dysfunction in individuals recently diagnosed with BD. The differences remained significant after adjusting for the presence of lifetime psychotic symptoms. We found no differences between MDD and BD during an acute mood episode.

The small sample size of individuals with BD.

The findings suggest a higher presence of subjective cognitive complaints among individuals recently diagnosed with BD in comparison to individuals with MDD during euthymia.