Exploring cognitive symptoms in patients with unipolar and bipolar major depression: A comparative evaluation of subjective and objective performance

Aim: This cross-sectional observational study aimed to assess objective and subjective cognitive deficits in patients with unipolar (UD) and bipolar depression (BD), focusing on their insight into actual cognitive abilities. Methods: A total of 124 participants were recruited: 84 patients with a current major depressive episode (43 with UD, 41 with BD) and 40 age- and gender-matched healthy controls. Cognitive assessments were conducted using the Screen for Cognitive Impairment in Psychiatry (SCIP) for objective evaluation and the Perceived Deficits Questionnaire-Depression-5-item (PDQ-d-5) for subjective assessment. Comparisons were performed using χ² tests for categorical variables and ANCOVA for continuous variables (to compare the severity of cognitive complaints and impairment, while controlling for illness duration and age at onset). The Pearson correlation coefficient was used to examine the relationship between subjective and objective measures. Results: In the objective assessment, 72.1 % of UD patients and 68.3 % of BD patients showed cognitive symptoms, with nearly half classified as moderate to severe. No significant differences were found between UD and BD in objective cognitive profiles. In subjective assessments, 39.5 % of UD patients and 46.3 % of BD patients scored below the median. BD patients reported worse subjective cognitive performance than UD patients, with lower total scores (11.1 ± 3.2 vs. 7.9 ± 4.4, p < < 0.001) and poorer performance in planning (2.8 ± 1.5 vs. 1.9 ± 1.4, p < < 0.001) and attention (3.4 ± 0.9 vs. 2.3 ± 1.5, p < .001) domains. Conclusion: This study confirms significant cognitive symptoms in both UD and BD patients. The discrepancy between subjective and objective cognitive performance in BD patients suggests a disconnect between perceived and cognitive abilities.