B-104: Cognitive Effects of Acute Transcranial Magnetic Stimulation: Preliminary Case Series

Abstract

Objective: While an established treatment for major depressive disorder, the acute cognitive effects of transcranial magnetic stimulation (TMS) require further characterization. This prospective case series examined cognitive changes in four consecutive patients undergoing acute left dorsolateral prefrontal cortex TMS for medication-refractory depression to characterize its specific neuropsychological effects. Method/Data Selection: Depression (PHQ-9) and anxiety (GAD-7) were assessed pre- and post-treatment alongside cognitive tests (Digit Span, Trail Making A/B, verbal fluency, list learning, recall, recognition). Raw scores were transformed into standardized z-scores using normative data for cross-domain comparison. Analyses included descriptive within-subject comparisons and exploratory Spearman correlations. Results/Data Synthesis: Post-TMS, depression and anxiety significantly improved (mean reductions 6.75, p=0.046; 4.75, p=0.036). Cognitive z-scores mostly remained stable or improved. Directional gains occurred in recognition (+10.25), processing speed/executive function (+4.00 to +5.25), verbal learning/recall (+1.00 to +3.00), and phonemic fluency (+2.25). Attention remained stable (−0.75). Semantic fluency declined (−2.75), showing a nonsignificant trend with anxiety improvement (ρ=-0.949, p=0.051). Conclusions: Acute TMS produced significant reductions in depressive and anxious symptoms without cognitive decline. Most cognitive domains remained stable or improved, particularly executive function and recognition memory. Ongoing enrollment will allow formal statistical evaluation of these relationships.