A PET Study to Determine Alterations in Serotonin Levels in Human Brain After a Single Dose of Escitalopram

Inclusion Criteria:

1. Signed informed consent
2. Male gender
3. Age 20 to 30 years
4. Healthy according to physical examination, ECG, MRI and blood chemistry

Exclusion Criteria:

1. Past or present psychiatric disease
2. Past or present brain disorder or injury, including loss of consciousness for more than five minutes
3. Past or present drug or alcohol abuse
4. Past or present use of antidepressant or antipsychotic medications
5. Regular use of medications (including herbals), that could interfere with the pharmacodynamics or pharmacokinetics of escitalopram
6. Significant abnormality on ECG
7. Structural abnormality in the brain confirmed by MR examination
8. Claustrophobia
9. Any metal devises or implants in the body
10. Intolerance to escitalopram or any of the components of the formula
11. Predisposition to motion sickness
12. Inability to understand and comply with the study requirements
13. Any medical condition that, in the opinion of the investigator, make the subject unsuitable for the study or put the subject at additional risk