Sample characteristics by group status.

Abbreviations: OSU, occasional stimulant users; CS, stimulant naïve comparison subjects; THC, marijuana; Prescription Stimulants = Adderall, Ritalin (used without prescription); BIS, Barrett impulsiveness scale; SSS, sensation seeking scale, BDI, Beck depression inventory; ADHD, attention deficit hyperactivity disorder. a Verbal IQ estimated via WTAR or NAART. b Maximum number of ADHD symptoms = 21 (n = 10 attention deficit symptoms, n = 11 hyperactivity symptoms). c ADHD (age 6–13) and conduct (<18 years) symptoms as assessed during in-person clinical interview (SSAGA). d refers to t-test between Low and High THC OSU. * Significance level of p<0.05. Sample characteristics by group status.