Participants in this study will be patients at the D. D. Eisenhower Army Medical Center who are experiencing a psychotic episode for the first time. Patients will be compared with 40 healthy volunteers (control group) matched with patients for age, gender, education, ethnic background, and occupational status. Patients and volunteers will have blood tests to determine the level of oxidative cell injury. Tests will be performed at onset of psychosis, and after 6 and 12 weeks of neuroleptic drug treatment. Medical histories and MRI scans will be used to examine the relationship of the laboratory tests to the clinical presentation.