Inclusion Criteria:
1. Women of nonchildbearing potential and men 18 to 55 years, inclusive.
2. Healthy as determined by medical evaluation, including medical and psychiatric history, physical and neurological examinations, ECG, vital sign measurements, and laboratory test results, as evaluated by the investigator.
3. Body mass index of 18.5 to 30.0 kg/m2 and a total body weight \>50 kg (110 lbs).
4. Sexually active men with a pregnant or a nonpregnant partner of childbearing potential must agree to comply with protocol contraception requirements during treatment and through 7 days post dose. In addition, male participants should not donate sperm for a minimum of 7 days following the last dose of IMP.
5. Capable of giving signed informed consent.
6. Ability, in the opinion of the investigator, to understand the nature of the trial and comply with protocol requirements.
Exclusion Criteria:
1. Current history of significant cardiovascular, pulmonary, gastrointestinal, renal, hepatic, metabolic, endocrine, hematological, immunological, or neurological disease that, in the opinion of the investigator or medical monitor, could compromise either participant safety or the results of the trial.
2. Current or past personal or family history of any psychiatric disorder as classified by DSM-5 criteria.
3. Epilepsy or a history of seizures except for a single seizure episode, eg, a childhood febrile seizure, a seizure related to trauma or alcohol withdrawal, or an unexplained loss of consciousness.
4. History of moderate to severe substance or alcohol-use disorder (excluding caffeine) within 12 months prior to signing the ICF.
5. Serious risk of suicide in the opinion of the investigator
6. Receipt of SARS-CoV2 vaccine or booster within 28 days of dosing with CVL-231, or plan to receive SARS-CoV2 vaccination or booster from Screening through 5 days after last dose of CVL-231.
7. Have recently been diagnosed with symptomatic COVID-19 or test positive for COVID-19 within 30 days prior to signing the ICF.
8. Either of the following:
* History of HIV, hepatitis B, or hepatitis C infection
* Positive result for HIV antibody, hepatitis B surface antigen, hepatitis B core antibody, or hepatitis C antibody
9. Positive drug screen for illicit drugs or a positive test for alcohol
10. 12-lead ECG demonstrating pre-defined abnormalities at Screening and Day -1 based on local evaluation.
11. Abnormal clinical laboratory tests or vital sign measurements at the Screening Visit and at Day -1 (check-in) for each period
12. Known to be allergic or hypersensitive to the IMP or any of its components.
13. Participation in any clinical trial within 90 days prior to signing the ICF.
