Altered cognitive network coupling in first-episode depression

Cognitive impairment is common in depression, yet most studies examine cognitive domains separately and rarely characterize patterns of cognitive coupling at the behavioral network level. This study investigated cognitive network architecture in first-episode depression and examined patterns of altered cognitive coupling among cognitive measures.

201 First-episode depression patients and matched healthy controls completed MCCB subtests (excluding social cognition). Group differences in cognitive performance were examined, and symptom-cognition associations were tested using Spearman correlations. Cognitive networks were constructed from pairwise correlation matrices. Global cognitive coupling was quantified as the mean absolute value of pairwise correlations among cognitive measures, and edge-wise differences were further examined.

Patients showed poorer performance in processing speed and verbal/visual memory, while attention/vigilance was relatively preserved. Greater depressive severity was associated with poorer performance in several cognitive measures, particularly processing speed, working memory, and attention/vigilance; anxiety severity was primarily associated with attention/vigilance measures, while psychotic symptoms showed domain-specific associations. Network analysis revealed higher global cognitive coupling in patients than controls (mean absolute correlation = 0.358 vs. 0.251), with increased pairwise coupling involving processing-speed and memory-related measures.

These findings suggest that altered cognitive coupling may reflect reduced differentiation among cognitive processes at the behavioral network level and highlight cognitive network analysis as a complementary framework for understanding early-stage cognitive dysfunction in depression.