CEREBRAL GLUCOSE-METABOLISM IN ADULTS WITH ATTENTION-DEFICIT HYPERACTIVITY DISORDER AFTER CHRONIC STIMULANT TREATMENT

Objective: The authors examined the effects of chronic stimulant treat ment on cerebral glucose metabolism in adults diagnosed with attention deficit hyperactivity disorder (ADHD), who were studied by means of p ositron emission tomography (PET) with [F-18]fluorodeoxy-glucose as th e tracer. Method: Each subject received two PET scans, the first befor e drug treatment and the second after treatment with daily oral doses, individually titrated for clinical effect, of either methylphenidate (N=19) or d-amphetamine (N=18) for a minimum of 6 weeks. The subjects completed behavioral self-report measures before and at the end of the medication period. Results: Neither stimulant medication changed glob al, or whole-brain, metabolism, although both drugs increased systolic blood pressure. Metabolism in only two of the 60 brain regions sample d was changed by methylphenidate, while d-amphetamine exhibited no eff ect on regional metabolism. Both drugs were associated with significan t improvement in behavior, as evidenced by improved ratings for restle ssness and ability to maintain attention. Conclusions: While the prese nt study does not demonstrate any robust metabolic effects of chronic stimulant treatment, the behavioral data strongly indicate that methyl phenidate and d-amphetamine are effective agents for the treatment of adults with ADHD.