Effects of intravenous dextroamphetamine on brain metabolism in adults with attention-deficit hyperactivity disorder (ADHD). Preliminary findings

The effects on brain metabolism of the intravenous (i.v.) administration of dextroamphetamine was assessed by positron emission tomography (PET) with [¹⁸F]-fluorodeoxyglucose (18-FDG) in 8 adults with attention-deficit hyperactivity disorder (ADHD). During the 3-hour 18-FDG PET session, each adult underwent the initial scan following i.v. infusion of placebo and a second scan following i.v. infusion of 0.15 mg/kg dextroamphetamine in a single-blind design. All subjects showed increased systolic/diastolic blood pressure and improved continuous performance task scores after dextroamphetamine. Global and regional metabolic rates were not significantly altered by the stimulant. When regional and global rates were normalized, the metabolic rates of only three cortical regions differed significantly between conditions. Individually, global metabolism increased in 4 subjects, was unchanged in 2, and decreased in 2 after stimulant infusion. No clinical characteristics differentiated these patients. I.V. infusion of dextroamphetamine did not significantly alter brain metabolism in ADHD adults in this preliminary study.