Presynaptic Imaging in Major Depressive Episodes After COVID-19

This study is using brain imaging scans (PET scans) to look at how dopamine-related brain activity changes in people who developed depression after a COVID-19 infection. Researchers want to understand the biological changes in the brain that may drive post-COVID depression. **You may be eligible if...** - You are between 18 and 75 years old - You had a mild or moderate COVID-19 infection and developed a new episode of depression within 3 months afterward - You are in generally good physical health **You may NOT be eligible if...** - You have taken antidepressants in the past month (or 6 weeks for fluoxetine) - You have taken stimulant medications, antipsychotics, or herbal supplements affecting the brain recently - You have a history of neurological disease (other than migraines or long COVID symptoms) - You have smoked cigarettes in the past 2 months - You have a history of severe substance or alcohol use disorder - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.