This study is for people with **Major Depressive Disorder (MDD)** who feel little joy or pleasure (anhedonia) and aren't getting better with their current antidepressants like **SSRI** (Selective Serotonin Reuptake Inhibitor) or **SNRI** (Serotonin Norepinephrine Reuptake Inhibitor). The study will look at details about the people and how their treatments are working. You can join if you're starting a new treatment along with your current one to help with your depression. However, you can't join if you have psychotic disorders, bipolar disorder, or other serious health issues. Also, if you haven't improved at all with your current medicine, you may not qualify. This study will help understand the best ways to treat people with these symptoms.

• The study involves starting a new treatment along with your current one.
• Participants will be monitored closely to see how well treatments work.
• This is an observational study, meaning no new experimental drugs will be given.

If you join, you will need to provide consent, which means you agree to let researchers collect and study your data safely and privately.