Cognitive changes in post-stroke depression patients undergoing treatment with transcranial direct current stimulation (tDCS): an exploratory, ancillary analysis of a randomized, sham-controlled clinical trial.

Abstract

Objective: Post-stroke depression affects approximately 40% of stroke survivors, with cognitive deficits being frequently observed. Transcranial direct current stimulation (tDCS) has shown promise in improving cognitive performance in stroke patients. We explored the effects of tDCS on cognitive performance in post-stroke depression.

Methods: We conducted an exploratory analysis of 48 patients from a double-blinded, shamcontrolled, randomized clinical trial that investigated the effects of tDCS on post-stroke depression. A neuropsychological battery was applied at baseline and endpoint. We assessed three key domains: 1) the Stroop effect, measured with Stroop Test components (the color-naming, word-reading, and word-color interference tasks); 2) processing speed, measured with the Trail Making Test and the Digit Symbol-Coding task; 3) executive function, assessed with the Digit Span test and the Frontal Assessment Battery. Linear mixed regression models were used to evaluate group-wise changes.

Results: We found that executive function worsened slightly in the active tDCS group and improved in the sham group in the adjusted models. Significant interactions were also found for the Frontal Assessment Battery.

Conclusions: We found no consistent evidence that tDCS significantly improved cognitive domains. The bidirectional association with cognition analysis suggests that the effects of tDCS may vary based on depression severity and task complexity.