Using Electrophysiology to Index Non-invasive Brain Stimulation Effects on Reward System Functioning in Depression

This study is using brain recordings (EEG) and non-invasive brain stimulation (TMS) to understand how the brain's reward system works differently in people with major depressive disorder (MDD). The findings could help improve future treatments for depression. **You may be eligible if...** - You are between 18 and 65 years old - You have normal or corrected-to-normal vision - (For participants with depression) You meet the clinical criteria for major depressive disorder and are on a stable psychiatric medication regimen for at least 1 month - You are able to attend in-person visits in San Francisco **You may NOT be eligible if...** - You have a history of neurological conditions such as seizures or significant head injury - You have a major medical condition that prevents safe participation in EEG, TMS, or MRI - You have substance dependence or current substance misuse - You are pregnant - You have claustrophobia - (For participants with MDD) You have a history of psychosis, bipolar disorder, or gambling disorder Talk to your doctor to see if this trial is right for you.