All patients met DSM-IV (American Psychiatric Association, 1994) criteria for schizophrenia (paranoid, n = 26; undifferentiated, n = 22; catatonic, n = 1; residual, n = 1), schizoaffective disorder (depressed type, n = 11; bipolar type, n = 9), schizophrenoform (n = 1) or psychosis not otherwise specified (n = 5; the clinical profile of these patients consisted of core psychotic symptoms, including thought disorder, disorganized thinking, paranoid thoughts, and hallucinations, placing them clearly in the range of schizophrenia spectrum disorders). Diagnoses were determined by consensus among senior diagnosticians, clinicians and clinical research interviewers (master level or above) on the basis of a semistructured interview (Nurnberger et al., 1994), which included items from commonly-used instruments (SAPS, SANS, SCID-P; Andreasen, 1983, 1984; Spitzer, Williams, Gibbon, & First, 1990). Thirty-two patients (43%) did not receive antipsychotic medications for at least 14 days before testing. The remaining 43 patients were treated with risperidone (n = 11), aripriprazole (n = 10), ziprasidone (n = 9), olanzapine (n = 6), quetiapine (n = 4), or clozapine (n = 3), with chlorpromazine equivalents ranging from 67
