A 7-year-old — can't sit still, poor grades; ADHD; behavioral + methylphenidate. ADHD (inattention, hyperactivity, impulsivity — <12y onset, 2 settings, 6 months: rule out — hearing, thyroid, sleep; treat — behavioral — parent training first; drugs — methylphenidate, atomoxetine): autism (social communication + repetitive — M-CHAT — early intensive behavioral), intellectual disability (IQ <70 + adaptive deficits — mild 50–70: special education, vocational; causes — Down's, fragile X; prevent — folic acid, iodized salt). The 2-setting impairment is ADHD — behavioral first.