Long-term effects of methylphenidate on neural networks associated with executive attention in children with ADHD: results from a longitudinal functional MRI study.
OBJECTIVE
Little is known about the long-term effects of stimulants on the functional organization of the developing brain. Nonacute effects of stimulants on neural activity related to three aspects of attention (alerting, reorienting, and executive control) were examined in children with attention-deficit/hyperactivity disorder (ADHD) using a longitudinal functional magnetic resonance imaging approach.


METHODS
Nine boys with ADHD were scanned while drug naïve (t1) and after 1 year of methylphenidate treatment (t2). Eleven matched controls were also investigated twice. ADHD children stopped medication 1 week before t2.


RESULTS
Although all of the children showed stable alerting and reorienting performance from t1 to t2, normal controls significantly improved their executive control performance at t2, whereas children with ADHD did not. Neurally, controls showed a larger increase in neural activity from t1 to t2 in regions critical to task performance (i.e., in the temporoparietal junction during reorienting of attention and in the anterior cingulate cortex during executive control) compared to the patient group. However, only children with ADHD showed a decrease in neural activity in the insula and putamen during reorienting, indicating a reduction in compensatory brain activation over time.


CONCLUSIONS
These data suggest that 1 year of MPH treatment may be beneficial, albeit insufficient, to show enduring normalization of neural correlates of attention.
Konrad
Kerstin
K
Child Neuropsychology Section, Department of Child and Adolescent Psychiatry, University Hospital Aachen, Germany. kkonrad@ukaachen.de
Neufang
Susanne
S
Fink
Gereon R
GR
Herpertz-Dahlmann
Beate
B
D001288:Attention / Q000187:drug effects*; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D002648:Child; D003071:Cognition / Q000187:drug effects*; D003463:Cues; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008774:Methylphenidate / Q000009:adverse effects* / Q000627:therapeutic use*; D009415:Nerve Net / Q000187:drug effects*; D012720:Severity of Illness Index
D008774:Methylphenidate