Insular Lesions as a Neural Substrate of Attentional Dysfunction in Post-Stroke Depression

Post-stroke depression (PSD) represents one of the most prevalent psychiatric complications after stroke, affecting up to one-third of survivors, and it can substantially influence both the extent of functional impairments and the recovery trajectory. A reciprocal relationship between depressive symptoms and cognitive dysfunction in this population has been commonly demonstrated, underscoring the need to clarify their intercorrelation and shared neuroanatomical underpinnings. To address this a combined cognitive dysfunction linked to PSD and imaging study, a total of 125 unilateral stroke patients were classified into two groups based on the presence of depressive symptoms using a BDI cutoff score of 14. Using principal component analysis (PCA) on 16 cognitive test variables from 64 patients with PSD and 61 without PSD, four principal components of cognitive function were extracted. Among these, the attention factor showed a significant group difference, with the PSD group exhibiting greater attentional impairments than the non-PSD group. Voxel-based lesion-symptom mapping (VLSM) further revealed that attentional performance was significantly associated with lesions in the left insula across groups. Importantly, the lesion clusters were more extensive in patients with PSD, suggesting a more pronounced role of insular damage in depressive symptomatology following stroke. Taken together, these findings highlight the pivotal contribution of the insula to both attentional processing and the pathophysiology of PSD, suggesting that the insula mediates attentional networks closely linked to depressive symptoms in stroke survivors.