Transcranial Direct Current Stimulation (tDCS) Neuromodulation of Executive Function Across Neuropsychiatric Populations

This study is testing whether mild electrical brain stimulation (called tDCS — small, painless currents applied to the scalp) can improve thinking and decision-making skills in people with various mental health or neurological conditions. **You may be eligible if...** - You are between 18 and 65 years old - You have a diagnosed condition such as traumatic brain injury, major depression, bipolar disorder, schizophrenia, ADHD, borderline personality disorder, or a substance use disorder - You are an outpatient (not currently hospitalized) **You may NOT be eligible if...** - You have a history of epilepsy or seizures - You have metal implants in your head or neck, a brain stimulator, vagus nerve stimulator, shunt, or pacemaker - You are pregnant or breastfeeding - You are currently dependent on substances (other than tobacco or cannabis) - You are unable to participate in cognitive testing Talk to your doctor to see if this trial is right for you.