An inpatient program with selected overnight stays, for childhood and adolescent neuropsychiatric disorders is ongoing. The condition currently under study is that of hyperactive children (HAC). Pharmacological compounds under study in these disorders include methylphenidate, amphetamine, piribedil, L-dopa, tryptophan, and mianserin. Pharmacokinetic studies with clinical responses are ongoing. Central neurotransmitters and their metabolites are being studied in plasma and urine. Amphetamine half-life in children is about one-third that on adults. Behavior and motor activity responses to d-Amphetamine occur during the absorption phase as determined by serial plasma amphetamine following a single dose. Urinary 3-methoxy-4-hydroxy-phenyl glycol shows a time-related decrease during tratment with d-amphetamine; homovanillic acid is unchanged. Piribedil is safe but clinically infeffective in HAC. L-dopa is minimally clincially effective in HAC.