Effect of Vortioxetine, Paroxetine, and Placebo on Sexual Functioning in Healthy Volunteers

The purpose of this study is to evaluate the effect of vortioxetine (10 and 20 mg, once daily) versus paroxetine (20 mg, once daily) on sexual functioning in healthy participants after 5 weeks of double-blind treatment.

The drug being tested in this study is called vortioxetine. This study will look at the effect of treatment on sexual functioning in healthy participants.

The study will enroll approximately 352 participants. Participants will be randomly assigned (by chance, like flipping a coin) to one of the four treatment groups-which will remain undisclosed to the patient and study doctor during the study (unless there is an urgent medical need):

* Vortioxetine 10 mg
* Vortioxetine 20 mg
* Paroxetine 20 mg
* Placebo (dummy inactive pill) - this is a capsule that looks like the study drug but has no active ingredient

All participants will be asked to take one tablet/capsule, daily, orally for up to 5 weeks.

This multicenter trial will be conducted in United States. The overall time to participate in this study is approximately 7 weeks. Participants will be contacted by telephone 2 weeks after last dose of study drug for a follow-up assessment.

Eligibility Criteria:
Inclusion Criteria:

1. Is sexually active and has been in a steady relationship and plans to remain in that relationship for the duration of the study.
2. Has a body mass index (BMI) of 18 to 35 kg/m\^2, inclusive, at the Screening and Baseline Visits.
3. If female, has a regular menstrual cycle.
4. Has normal sexual functioning, as defined by a Changes in Sexual Functioning Questionnaire (CSFQ-14) total score \>47 (men) or \>41 (women) at the Screening and Baseline Visits.
5. If females, taking allowed hormonal contraceptives is on a stable dose for ≥3 months prior to the Baseline Visit and continues on the stable dose for the duration of the study.

Exclusion Criteria:

1. Has received vortioxetine and/or paroxetine in a previous clinical study or as a therapeutic agent.
2. Is positive for hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (HCV) antibodies, or human immunodeficiency virus (HIV) at the Screening Visit or has any known sexually transmitted diseases.
3. Has glycosylated hemoglobin (HbA1c) ≥7% at the Screening Visit.
4. Has a clinically significant abnormal electrocardiogram (ECG) at the Screening Visit.
5. Has a known history of or currently has increased intraocular pressure or is at risk of acute narrow-angle glaucoma.
6. Has a history of depression or any other psychiatric illness.
7. Has a significant risk of suicide according to the investigator's clinical judgment, or has made a suicide attempt in the previous 6 months.
8. Has current sexual dysfunction, or a history of a diagnosis or treatment of sexual dysfunction.
9. Has had a surgical or medical procedure on reproductive/genitourinary organs (excluding uncomplicated vasectomy and tubal ligation).
10. If female, has polycystic ovarian syndrome.
11. Has hypogonadism or has a free testosterone value outside the normal range at the Screening Visit that is indicative of hypogonadism.
12. Has a thyroid-stimulating hormone (TSH) value outside the normal range at the Screening Visit that is deemed clinically significant by the investigator.