The purpose of this study is to assess the effects of aticaprant on QT/ QT interval corrected for heart rate (HR) (QTc) intervals and electrocardiogram (ECG) morphology at therapeutic and supratherapeutic exposures in healthy adult participants.

Inclusion Criteria:

• Healthy on the basis of physical examination, medical history, vital signs, and 12-lead electrocardiogram (ECG) performed at screening and admission to the study center on Day -1 of the first treatment period. Minor abnormalities in ECG, which are not considered to be of clinical significance by the investigator, are acceptable
• Body mass index (BMI; weight [kilograms {kg}/ height square [meter square {m^2}]) between 18 and 30.0 kg/m^2 (inclusive), and body weight not less than 50 kg at screening
• All female participants must have a negative serum pregnancy test (Beta-human chorionic gonadotropin [Beta-hCG]) at screening and a negative urine pregnancy test at admission to the study site on Day -1 of the first treatment period
• A woman must agree not to donate eggs (ova, oocytes) or freeze for future use for the purposes of assisted reproduction during the study and for a period of at least 90 days after receiving the last dose of study intervention
• Non-smoker (not smoked for 3 months prior to screening)

Exclusion Criteria:

• History of or current significant medical illness including (but not limited to) cardiac arrhythmias or other cardiac disease, hematologic disease, lipid abnormalities, bronchospastic respiratory disease, diabetes mellitus, hepatic or renal insufficiency, thyroid disease, Parkinson's disease, infection, or any other illness that the investigator considers should exclude the participant
• History of additional risk factors for Torsade de Pointes or the presence of a family history of short QT syndrome, long QT syndrome, sudden unexplained death at a young age (less than/equal to 40 years), drowning or sudden infant death syndrome in a first degree relative (that is, biological parent, sibling, or child)
• Any skin condition likely to interfere with electrocardiographic electrode placement or adhesion
• Breast implant or a history of thoracic surgery likely to cause abnormality of the electrical conduction through thoracic tissues
• History of malignancy within 5 years before screening (exceptions are squamous and basal cell carcinomas of the skin and carcinoma in situ of the cervix, or malignancy, which is considered cured with minimal risk of recurrence)](streamdown:incomplete-link)

The data sharing policy of the Janssen Pharmaceutical Companies of Johnson & Johnson is available at www.janssen.com/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu