Delta 9-tetrahydrocannabinol induces dopamine release in the human striatum.
Matthijs G. Bossong, Bart N M Van Berckel, Ronald Boellaard, Lineke Zuurman, Robert C Schuit, Albert D Windhorst, Joop van Gerven, Nick F. Ramsey, Adriaan A Lammertsma, René S. Kahn
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology February 2009 DOI: 10.1038/npp.2008.138 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 7 |
| Population | Healthy human subjects |
| Measures | [11C]raclopride binding |
| Topics | Cannabis |
| Key findings | THC inhalation reduced [11C]raclopride binding in the ventral striatum and precommissural dorsal putamen, indicating increased dopamine release, but not in other striatal subregions. The authors propose that THC shares addictive potential with other drugs of abuse and that the endogenous cannabinoid system regulates striatal dopamine release. |
Abstract
The influence of cannabis on mental health receives growing scientific and political attention. An increasing demand for treatment of cannabis dependence has refueled the discussion about the addictive potential of cannabis. A key feature of all addictive drugs is the ability to increase synaptic dopamine levels in the striatum, a mechanism involved in their rewarding and motivating effects. However, it is currently unknown if cannabis can stimulate striatal dopamine neurotransmission in humans. Here we show that Delta 9-tetrahydrocannabinol (THC), the main psychoactive component in cannabis, induces dopamine release in the human striatum. Using the dopamine D(2)/D(3) receptor tracer [(11)C]raclopride and positron emission tomography in seven healthy subjects, we demonstrate that THC inhalation reduces [(11)C]raclopride binding in the ventral striatum and the precommissural dorsal putamen but not in other striatal subregions. This is consistent with an increase in dopamine levels in these regions. These results suggest that THC shares a potentially addictive property with other drugs of abuse. Further, it implies that the endogenous cannabinoid system is involved in regulating striatal dopamine release. This allows new directions in research on the effects of THC in neuropsychiatric disorders, such as schizophrenia.