2. Current or past DSM-IV or DSM-5 diagnosis of a psychiatric disorder (other than alcohol in AD participants and nicotine/caffeine use disorders) that required hospitalization (any length), or chronic medication management (more than 4 weeks) and that could impact brain function at the time of the study as determined by history and clinical exam. The following chronically used medications are exclusionary from the study: analgesics containing narcotics; anorexics (sibuteramine); antianginal agents; antiarrhythmics; antiasthma agents that are systemic corticosteroids; antibiotics; anticholinergics; anticoagulants; anticonvulsants; antidepressants; antidiarrheal preparations; antifungal agents (systemic); antihistamines (sedating); antihypertensives; anti-inflammatory drugs (systemic); antineoplastics; antiobesity; antipsychotics; antivirals (except for treatment of HSV with agents without CNS activity, e.g. acyclovir, ganciclovir, famciclovir, valacyclovir); anxiolytics; cough/cold preparations (dextromethorphan preparations, pseudoephedrine); hormones (exceptions: thyroid hormone replacement, oral contraceptives, and estrogen replacement therapy); insulin; lithium; muscle relaxants; psychotropic drugs not otherwise specified (nos) including herbal products (no drugs with psychomotor effects or with anxiolytics, stimulant, antipsychotic, or sedative properties); sedatives/hypnotics. Note that nicotine and/or caffeine use will not exclude participants.