This study will assess an adjunctive treatment for major depressive disorder (MDD) called Aticaprant. Adults with MDD that are currently on an antidepressant but continue to experience prominent anhedonia may qualify.

This is a study to learn more about the use of a study medicine for the treatment of Idiopathic Hypersomnia (IH). The total duration of the study is approximately 3 1/2 months. Men and women between the ages of 18-75, with a primary diagnosis of IH, may be eligible.

The study is designed to look at the usefulness and safety of Solriamfetol (versus placebo) for the treatment of excessive sleepiness associated with shift work disorder (SWD). Study staff nor the participants will know if they are receiving a study drug or placebo. Participants will be male or female subjects 18-65 years old with a diagnosis of SWD. The study will last approximately 17 weeks, with 6 in-person visits and 8 remote visits for each participant.