Study of the impact of transcranial direct current stimulation on impulsivity in healthy and clinical populations: A literature review.
BACKGROUND Impulsivity is a multidimensional construct comprising motor and cognitive components, subserved by partially dissociable prefrontal networks. Transcranial direct current stimulation (tDCS) has emerged as a promising tool to modulate these circuits, yet its domain-specific effects remain poorly defined. METHODS A systematic review of studies published up to March 2025 was conducted. Eligible studies assessed tDCS effects on impulsivity-related outcomes, including response inhibition, delay discounting, risk taking, planning, and impulsive behaviour. Results were synthesised according to stimulation parameters, cortical targets, population characteristics, and impulsivity domains. RESULTS Across studies, 156 positive, 28 negative, and 133 non-significant outcomes were identified. Converging evidence indicates that tDCS most reliably enhances motor impulsivity, particularly response inhibition, following stimulation of right-lateralised prefrontal regions such as the inferior frontal gyrus and dorsolateral prefrontal cortex. In contrast, effects on cognitive impulsivity domains were inconsistent and highly context-dependent, influenced by task demands, stimulation protocols, and inter-individual variability. Evidence for improvements in planning remains limited but promising. CONCLUSIONS tDCS exerts positive effects on inhibitory control but shows limited reliability for higher-order decision-making processes. These findings underscore the need for circuit-specific targeting and methodological standardisation to advance precision neuromodulation approaches in psychiatry.