- Off all psychotropic and other types of drugs likely to interact with serotonin transporters and 5-HT1A receptors for at least 21 days. Allowed short-acting benzodiazepines for distressing anxiety or insomnia (up to 24 hours prior to each PET scan). Patients will be off neuroleptics for 3 weeks and off fluoxetine for 6 weeks prior to study. Off serotonin depleting drugs such as reserpine for 3 months. Patient will also be off anti-coagulant/anti-platelet treatment such as coumadin, with the exception of aspirin for 10 days.