Study of Safety, Blood Levels and Brain Receptor Occupancy of GSK598809 Using PET Imaging in Health Males.

Inclusion Criteria: Healthy male subjects, defined as individuals who are free from clinically significant illness or disease as determined by their medical history (including family), physical examination, laboratory studies, and other tests. * Aged 25-55 years inclusive, at screening visit. * Body weight \> 50 kg and body mass index (BMI) between 19.0 - 29.0 kg/m2 inclusive. * Capable of giving informed consent and can comply with the study requirements and timetable. * Self-administered Beck Depression Inventory II scale total score no greater than 9, and suicide question score of zero. * Able to read, comprehend and record information. * A signed and dated written informed consent is obtained from the subject. Exclusion Criteria: * The physician responsible considers the subject unfit for the study based upon medical history, physical examination and psychiatric history and evaluation. * History of a drug or other allergy which in the opinion of the physician responsible contraindicates their participation in the study. * Participation in a clinical trial and has received a drug or a new chemical entity within 30 days or 5 half-lives, or twice the duration of the biological effect of any drug(whichever is longer) prior to the first dose of current study medication. * Exposure to more than four new chemical entities within 12 months prior to the first dosing day. * A screening ECG outside of ranges specified in the protocol * Pulse rate \<55 or \>100 bpm OR a systolic …