Exclusion criteria for both groups were: 1) positive diagnoses for schizophrenia or schizophreniform disorder, assessed using the computerized Diagnostic Interview Schedule (c-DIS) (Robins et al., 1998), 2) manic episode within the prior 12 months, 3) history of drug dependence other than nicotine or caffeine, 4) significant history of head trauma or cranial surgery, 5) history of diabetes, stroke, or hypertension that required an emergent medical intervention, or of other significant neurological disease, 6) laboratory evidence of hepatic disease, 7) clinical evidence of Wernicke-Korsakoff syndrome, and 8) current substance abuse other than caffeine or nicotine.
