Stimulant medication and prefrontal functional connectivity during working memory in ADHD: a preliminary report.
OBJECTIVE
Recent theoretical and empirical work suggests that while unmedicated, children with ADHD have a deficit in subcortical processing that leads to greater and more varied prefrontal cortical (PFC) activation, compared to (a) age-matched control participants and (b) their own brain activity while on stimulant medication. This pattern has been described elsewhere as inefficient.


METHODS
Functional magnetic resonance imaging (fMRI) and functional connectivity analyses were used during a working memory task for five female adolescents with ADHD, aged 11 to 17 years, both on and off their usual dose of stimulant medication.


RESULTS
On medication, adolescents with ADHD demonstrated less PFC activation and less functional connectivity between frontal and subcortical regions compared to off medication.


CONCLUSIONS
Because of the small sample size, results are presented as preliminary findings which await replication in a larger sample. However, these findings lend support to the idea that remediation of inefficiencies in PFC function for individuals with ADHD by stimulant medication may be related, in part, to frontal-subcortical connectivity.
Sheridan
Margaret A
MA
Harvard University, Boston, MA 02115, USA. margaret.sheridan@childrens.harvard.edu
Hinshaw
Stephen
S
D'Esposito
Mark
M
D000293:Adolescent; D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000503:physiopathology*; D001479:Basal Ganglia / Q000503:physiopathology; D001931:Brain Mapping; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008570:Memory, Short-Term / Q000502:physiology*; D009415:Nerve Net / Q000503:physiopathology*; D009483:Neuropsychological Tests; D010865:Pilot Projects; D017397:Prefrontal Cortex / Q000503:physiopathology*
D000697:Central Nervous System Stimulants