Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that delivers a low-intensity electrical current (typically 1–2 mA) through electrodes placed on the scalp to modulate brain activity.
It influences neuronal excitability by altering the resting membrane potential: anodal stimulation increases cortical excitability, while cathodal stimulation decreases it.
This polarity effect enables targeted modulation of specific brain regions.
tDCS induces intracellular changes, including glial activation and alterations in cAMP and calcium concentrations, leading to synaptic plasticity mechanisms like long-term potentiation and depression.
The current flows between an anode (positive) and cathode (negative) electrode, with neuronal effects dependent on electrode placement and current direction.
tDCS shows moderate efficacy for major depressive disorder (MDD), particularly treatment-resistant cases.
Schizophrenia: it improves negative symptoms and working memory.
Stroke Rehabilitation: May enhance activities of daily living post-stroke.
Neuropathic Pain: Emerging evidence for spinal cord injury-related pain.
tDCS is well-tolerated with minimal side effects-mild scalp irritation.
Sessions typically last 20–30 minutes.
Devices include a battery-powered current generator and electrodes, with protocols tailored to target brain regions.
Home-based administration with remote supervision is feasible and effective.