Characteristics and clinical correlates of persistent anhedonia in the remitted patients with bipolar depression.

Background: Anhedonia is increasingly recognized as a persistent symptom over the course of disease. Findings on the symptoms of anhedonia in remitted bipolar disorder are inconsistent, and little is known about the characteristics and relative factors in these patients. This study was conducted to explore the characteristics and clinical correlates of anhedonia in remitted patients with bipolar depression.

Methods: Sixty bipolar patients in partial remission following a recent depressive episode and sixty healthy controls were recruited from September 2023 to December 2023. Anhedonia was evaluated using the Snaith-Hamilton Pleasure Scale (SHAPS), the Temporal Experience of Pleasure Scale (TEPS), the Revised Social Anhedonia Scale-Chinese Version (RSAS-C), and the Revised Physical Anhedonia Scale-Chinese Version (RPAS-C). Depressive, anxious, manic symptoms were assessed using the 17-item Hamilton Depression Rating Scale (HAMD-17), the 14-item Hamilton Anxiety Scale (HAMA-14), the Young Mania Rating Scale (YMRS), and cognitive function using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). T-tests and MANCOVA were conducted to compare clinical scale scores between remitted bipolar patients and healthy controls. Pearson and partial correlation analyses (adjusted for antidepressant dose and mean body mass index, BMI) were used to examine correlates of anhedonia in remitted bipolar patients.

Results: The scores on RSAS-C and RPAS-C were significantly higher for remitted bipolar patients than for healthy controls (P < 0.05), whereas no significant differences were found in scores on the TEPS and SHAPS between the two groups. Pearson correlations showed social and physical anhedonia negatively correlated with total RBANS and several subdomains, while consummatory pleasure positively correlated with delayed memory subscale. After adjusting for antidepressant dose and BMI, partial correlations confirmed that social anhedonia was negatively associated with total RBANS and immediate memory, visuospatial/constructional, language, and attention subscales; physical anhedonia was negatively associated with total RBANS, immediate memory, and attention; and consummatory pleasure was positively correlated with attention subscale. No significant associations were found between HAMD-17 and anhedonia scales.

Conclusion: Our findings indicate persistent social and physical anhedonia in bipolar patients in partial remission following a recent depressive episode. Moreover, cognitive function is significantly correlated with the severity of social and physical anhedonia, independent of antidepressant dosage.