Inclusion Criteria:
* Group 1: Healthy adult Japanese male or female;
• Japanese participants must be first-generation Japanese of full Japanese parentage residing outside of Japan for less than 5 years.
* Group 2: Healthy adult Han Chinese male or female
• Han Chinese participants must be first-generation Han Chinese of full Chinese parentage residing outside of China for less than 5 years.
* Group 3: Healthy adult male or female volunteers of African, European, or Latin American descent.
* A condition of general good health, based upon the results of a medical history, physical and neurological examination, vital signs, laboratory profile and 12-lead ECG.
Exclusion Criteria:
* Current diagnosis or history of any clinically significant mental health disorder, cardiovascular disorder, metabolic disorder, or other disorder requiring pharmacologic or other medical treatment. (Previous psychological support without a diagnosed history of a mental health disorder would not be considered exclusionary.)
* Clinically significant personal or familial history (first degree relative) of epilepsy, seizures, convulsions, or other seizure disorder (excluding febrile seizures as a child), previous head trauma or other risk factor for seizure (e.g., electrolyte disturbances, or structural neurological disorders).
* Any use of psychoactive substances (including ketamine, esketamine, MDMA, cannabinoids, or nitrous oxide) during the 6 weeks prior to confinement.
