In this study, we are testing whether a higher dose of a non-invasive brain stimulation technique, called transcranial direct current stimulation (tDCS), can be safely used in people with depression. Participants will come to the Brain Stimulation Lab and receive mild electrical stimulation through electrodes placed on their scalp.

The study begins with a safety run-in, where the first few participants will receive stimulation at gradually increasing levels (2, 4, and 6 milliamps) while being closely monitored. If no serious side effects are found, later participants will receive repeated 6 milliamp sessions for 5 days total. We will check skin comfort, mood, and overall tolerability after each session.