Children (N=216) from the New York metropolitan area were recruited via preschools and direct referrals into a longitudinal study when they were 3 – 4 years old (Baseline; BL) and followed up annually for three subsequent assessments (F1, F2, & F3). Parents and teachers completed the Attention-Deficit/Hyperactivity Disorder Rating Scale, Fourth Edition (ADHD-RS-IV; DuPaul, Power, Anastopoulos, & Reid, 1998). Children were accepted into the study as either TD (fewer than 3 items rated as Often or Very Often by both parents and teachers; N=76) or H/I (at least 6 symptoms rated as Often or Very Often by either parent or teacher; N=140). Children were excluded if they had a Full-Scale IQ less than 80, as measured by the Wechsler Preschool and Primary Scale of Intelligence, 3rd Edition (WPPSI-III; Wechsler, 2002), a pervasive developmental or neurological disorder, were taking systemic medications, including stimulants for ADHD, or if they or their parents were not fluent in English.
