NEUROIMAGING OF INHIBITION &STIMULANT RESPONSE IN ADHD

Project: Research project

Project Details

Description

DESCRIPTION: (provided by applicant) The overall objective of this project is
to develop a system-level model of brain-behavior relationships in ADHD. This proposal builds on previous findings of the P1 and CoPIs using a combination of
event-related potentials (ERP), behavioral tasks, anatomical magnetic resonance
imaging (MRI) and neuropsychology assessments in ADHD children. In the proposed
project, we will use a within-subject, multi-methodological approach to clarify
the relationship between anatomical and functional imaging abnormalities in
ADHD. We will obtain ERP, event-related functional MRI (ER-fMRI), and
anatomical MRI at baseline in four cohorts of subjects: ADHD subjects with no
history of psychopharmacological treatment, ADHD subjects who have been
chronically treated with stimulant medication, subjects with Reading Disorders
(RD) who have no history of ADHD or psychopharmacological treatment, and
control subjects. Subjects will perform both the ERP and the Stroop task during
the ERP and ER-fMRI studies. After baseline studies, ADHD subjects will undergo
a 5-week double blind placebo controlled trial of methylphenidate to establish
if a child is a responder or non-responder to methyiphenidate and to determine,
for the responders, which is the optimal dose. Subjects with ADHD will then
undergo ERP and er-fMRI twice more, once on placebo and once on the best dose
of stimulant, again performing the Stroop and Stop Signal Task. Our hypotheses
are: 1) Relative to controls and RD subjects, ADHD children will show decreased
right frontal and anterior cingulate volume as well as decreased caudate
volume. 2) On ERP, ADHD subjects will show decreased N200 and P3a responses to
the stop signal on ERP and decreased anterior medial negativity to Incongruent
vs. Congruent stimuli on the Stroop. 3) On er-fMRI, they will show decreased
activity in the anterior cingulate during the Stroop task, and decreased right
inferior prefrontal cortex (PFC) activity in response to the stop signal. 4)
ERP and er-fMRI differences in ADHD children will be attenuated on
methyiphenidate relative to placebo. The magnitude of these changes will
correlate with clinical response of ADHD symptoms to methylphenidate. 5) We
will control for effects of gender and age, in particular girls with ADHD may
not show the same neurobiological mechanisms as boys.
StatusFinished
Effective start/end date6/1/025/31/06

Funding

  • National Institutes of Health: $333,903.00
  • National Institutes of Health: $299,498.00
  • National Institutes of Health: $35,214.00
  • National Institutes of Health: $290,233.00

ASJC

  • Medicine(all)

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