Exclusionary criteria were: parental history of bipolar, psychotic, or antisocial personality disorder; complicated or premature birth (<34 weeks gestation); any indication of in utero alcohol, tobacco, or illicit drug exposure; history of neurological or serious medical illness, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV, American Psychiatric Association, 1994) Axis I disorder, traumatic brain injury with loss of consciousness > 2 min., or learning disabilities; left-handedness; lifetime use of any psychiatric medication; sensory impairments; non-fluency in English; MRI contraindications; more than 6 lifetime alcohol (and no more than 1 drink per drinking occasion) use occasions; and any lifetime tobacco, marijuana, or other illicit drug use. Groups were statistically equivalent on gender, ethnicity, socioeconomic status, IQ, academic grade point averages, age, pubertal development, and body mass index (see Table 1).
