The study is designed to look at the usefulness and safety of TAK-994 or placebo for treatment of Narcolepsy. Narcolepsy is a chronic sleep disorder characterized by overwhelming daytime drowsiness and sudden attacks of sleep. Study staff nor participants will know if they are receiving study drug or placebo. Participants will be male or female subjects 18-65 years old with a diagnosis of narcolepsy. The study treatment period from screening to follow-up will last approximately up to 110 days, requiring up to twelve visits. Four overnight stays and four all day visits will be required.

The purpose of this study is to evaluate the safety and effectiveness of suvorexant versus placebo (an inactive substance) on individuals with alcohol use disorder experiencing insomnia during abstinence. Participants will be 18 years of age or older. Twenty-four participants will have a 50:50 chance to the study drug or placebo. The study participation will last approximately six weeks, requiring four visits.

Candidates for this study may or may not report disturbances in odor perception as their primary reason for seeking treatment at MUSC. This study is designed to collect long term, observational data from patients who are being treated with routine clinical care in health clinics at MUSC. Data from clinical questionnaires will be de-identified and stored in a database.

The Sleep Research Data Repository (SRDR) aimed to systematically collect, analyze and store for future research sleep and sleep disorders related biological and psychological information. It will include sleep physiological measurements and the results of interviews, questionnaires, and laboratory tests. The SRDR will contain sleep related information obtained from healthy subjects and patients with psychiatric, substance abuse, neurological disorders, or any medical conditions associated with sleep disturbances. SRDR data will be made available to current and future IRB-approved investigators associated with this protocol.