The TERPSIS Study is evaluating whether a once-weekly oral investigational medication is safe and improves symptoms associated with a lack or loss of interest in usually pleasurable activities in participants with major depressive disorder (MDD).

Who May Qualify

Eligible participants must:

• Be 18 to 65 years of age
• Have a diagnosis of depression
• Be currently on or have previously been on antidepressant medication(s)
• Not be pregnant or breastfeeding or planning to become pregnant during the study

Study Participation

The total length of the TERPSIS Study is approximately 20 weeks. This includes a 4-week screening period to make sure the research study is a good match for you, an 8-week treatment period in which you will receive either the investigational medication or placebo, and an 8-week follow-up period to check on your health after stopping the assigned study treatment. Participants in the TERPSIS Study will be able to stay on their current antidepressant medication(s) while in the study.

Throughout the research study, your study doctor may perform a number of tests and procedures, including but not limited to:

• Recording your medical history
• Conducting a physical exam
• Measuring your vital signs
• Conducting a pregnancy test (if applicable)
• Collecting blood and urine samples