Exclusion criteria for all groups were as follows: (1) lifetime or current diagnosis of schizophrenia or schizophreniform disorder using the computerized Diagnostic Interview Schedule (c-DIS) (Bucholz et al. 1991; Levitan et al. 1991; Erdman et al. 1992), (2) significant history of head trauma or cranial surgery, (3) history of significant neurological disease, (4) history of diabetes, stroke, or hypertension that required emergent medical intervention, (5) laboratory evidence of hepatic disease, or (6) clinical evidence of Wernicke–Korsakoff syndrome.
