drinking (>7 drinks in a week or >4 drinks in a day) or illicit drug use during pregnancy; parental history of bipolar I or psychotic disorder; left handedness; non-fluency in English; MRI contraindications; and clinically abnormal brain anatomy. Having surpassed these exclusionary criteria, participants were classified as: (1) Controls with limited substance use history (i.e., <5 lifetime occurrences of marijuana use, <50 lifetime drinks, <2 lifetime episodes of other drug use); or (2) MJ+ALC users with history of lifetime marijuana use between 180 to 1800 times and lifetime drinks between 50 and 700. The most recent marijuana use occurred 24 hours prior to imaging and last heavy alcohol use (4 or 5 alcoholic beverages in one sitting for females and males, respectively) was 3 days prior (see Table 1), verified by breathalyzer and urine toxicology. MJ+ALC users were excluded if they met criteria for a DSM-IV Axis I disorder other than a marijuana or alcohol use disorder. Informed assent and consent were obtained from participants and legal guardians in accordance with UCSD Human Research Protections Program procedures.
