1. Current significant medical condition such as neurological, cardiovascular, endocrine, renal, liver, or thyroid pathology.
2. History of or current neurological or significant psychiatric disorder such as schizophrenia or bipolar disorder (DSM-IV Axis 1).
3. History of significant head trauma. 4. Women who are pregnant or nursing, or fail to use one of the following methods of birth control unless she or partner is surgically sterile or she is postmenopausal (hormone contraceptives [oral, implant, injection, patch, or ring], contraceptive sponge, double barrier [diaphragm or condom plus spermicide], or IUD).
5. Regular or current significant use of any prescription, herbal or illegal psychotropic medications (e.g., antidepressants, antipsychotics, anxiolytics, ecstasy) in the past 6 mo, with no current illegal drug use confirmed by urine toxicology (except for cocaine and marijuana when relevant).
6. Significant substance misuse (including alcohol, and excluding cannabis and marijuana when relevant) that in the PI’s determination interferes with the study results or safety of the subject.
7. Have MRI-incompatible implants and other contraindications for MRI, such as a pacemaker, artificial joints, non-removable body piercings, claustrophobia, etc.
8. Subjects with history of prior radiation exposure for research purposes within the past year such that participation in this study would place them over FDA limits for annual radiation exposure. This guideline is an effective dose of 5 rem received per year.
9. Subjects with current, past or anticipated exposure to radiation in the work place within one year of proposed research PET scans.
10. Subjects with history of IV drug use which would prevent venous access for PET tracer injection.