Study to Determine D-amino Acid Oxidase Brain Enzyme Occupancy of TAK-831 After Single-dose Oral Administration

Inclusion Criteria

• Is capable of understanding and complying with protocol requirements.
• Signs and dates a written, informed consent form and any required privacy authorization prior to the initiation of any study procedures.
• Is in good health as determined by physical examination, electrocardiogram (ECG), and laboratory evaluations.
• Is a healthy male aged 25 to 55 years, inclusive, at the time of informed consent and first injection of the PET tracer.
• Weighs at least 45 kilogram (kg) and has a body mass index (BMI) from 18.0 to 30.0 kilogram per square meter (kg/m^2), inclusive, at Screening.
• Agrees to use adequate contraception from signing of informed consent throughout the duration of the study and for 90 days after last dose.

Exclusion Criteria

• Has received any investigational compound or device within 3 months or 5 half-lives, whichever is longer, prior to Check-in for Screening.
• Is an immediate family member, study site employee, or is in a dependent relationship with a study site employee who is involved in the conduct of this study (example, spouse, parent, child, sibling) or may consent under duress.
• Has uncontrolled, clinically significant (CS), neurologic (including seizure disorder), cardiovascular, pulmonary, hepatic, renal, metabolic, gastrointestinal (GI), urologic, immunologic, or endocrine disease or psychiatric disorder, or other abnormality, which may impact the ability of the participant to participate or potentially confound the study results.
• Has a known hypersensitivity to any component of the formulation of TAK-831 or related compounds, or to [18 F]PGM299 or to any of its components.
• Has a positive urine or breath test result for drugs of abuse (defined as any illicit drug use), ethanol (alcohol), or cotinine at Screening, Check-in for Baseline Imaging/Confinement Period 1, or Check-in for the Treatment/Confinement Period 2 (Day -1) for a participant participating in Set A or at Screening, Check-in for Tracer TEST PET Imaging/Confinement Period 1, or Check-in for RE-TEST PET Imaging/Confinement Period 2 for a participant participating in Set B.
• Has a history of drug abuse (defined as any illicit drug use) or a history of ethanol (alcohol) abuse within 1 year prior to the screening visit or is unwilling to agree to abstain from ethanol (alcohol) and drugs throughout the study.
• Has taken any medication, supplements, or food products during the time periods listed in the excluded medications and dietary products table.
• Intends to donate sperm during the course of this study or for 90 days after the last dose of study medication.
• Has evidence of current cardiovascular, central nervous system, hepatic, or hematopoietic disease; renal, metabolic or endocrine dysfunction; serious allergy, asthma, hypoxemia, hypertension, or allergic skin rash; or there is any finding in the participant's medical history, physical examination, or safety laboratory tests giving reasonable suspicion of a disease that would contraindicate taking TAK-831 or a similar drug in the same class, which might interfere with the conduct of the study. This includes, but is not limited to, peptic ulcer disease and cardiac arrhythmias.
• Has current or recent (within 6 months) GI disease that would be expected to influence the absorption of drugs (that is, a history of malabsorption), any surgical intervention known to impact absorption (example, bariatric surgery or bowel resection), esophageal reflux, peptic ulcer disease, erosive esophagitis, or frequent (more than once per week) occurrence of heartburn.
• Has a history of cancer, except basal cell carcinoma that has been in remission for at least 5 years prior to Day 1.
• Has a positive test result for hepatitis B virus surface antigen (HBsAg), hepatitis C virus (HCV) antibody (HCAB), or human immunodeficiency virus (HIV) infection at Screening.
• Has used nicotine-containing products (including but not limited to cigarettes, pipe