Imaging opioid release after stimulants in adults with ADHD
Research type
Research Study
Full title
A [11C]Carfentanil PET study to investigate endogenous opioid release in adults with ADHD after one oral dose of Dexamphetamine
IRAS ID
126904
Contact name
Katya Rubia
Contact email
Duration of Study in the UK
1 years, 5 months, 0 days
Research summary
The main purpose of this study is to investigate the role of a specific brain messenger system, called “the opioid system”, in male adults with ADHD. It is possible to measure opioid receptor levels using a special chemical that has been labeled with a tiny does of radioactivity and that can be detected with a type of brain scan called Positron Emission Tomography (PET). Furthermore, if the opioid system is stimulated to release opioid molecules, such a release can be detected by a reduction in binding of the radioactive agent used to label the opioid receptors. The brain’s release of opioids can be triggered by a dose of amphetamine. Thus, two [11C]carfentanil PET scans are required to measure the aspects of the opioid system of interest in this study; one scan to measure the baseline level without any stimulation, and one scan after giving a dose of amphetamine.
It is hypothesized that:
1) A dose of Dexamphetamine will reduce [11C]Cartenfanil binding (i.e., increase µ-opioid release) in ADHD adults (as in controls)).
2) The [11C]cartenfanil binding potential (i.e., amount of µ-opioid release) after one dose of Dexamphetamine in ADHD adults is lower from that in healthy adults (lower)
3) ADHD adults will have higher [11C]carfentanil binding potential (i.e., decreased µ-opioid release) than healthy controls at baseline.The findings of this study have important clinical implications:
1) Opioid release in ADHD patients after dexamphetamine could be the basis for the addictive potential of stimulants.
2) Differential µ-opioid release after stimulant medication would suggest differences between healthy controls and ADHD patients in mechanisms of action and in the abuse potential of amphetamines.
3) Differences in µ-opioid receptor availability at baseline in ADHD relative to controls could reflect a new underlying neurobiological mechanism for ADHD leading to new research and treatment development.REC name
London - West London & GTAC Research Ethics Committee
REC reference
14/LO/1795
Date of REC Opinion
1 Dec 2014
REC opinion
Further Information Favourable Opinion