Fatty Acid Amide Hydrolase Binding in Brain of Cannabis Users Imaging With the Novel Radiotracer
One of the major mechanisms for terminating the actions of the endocannabinoid anandamide is hydrolysis by fatty acid amide hydrolase (FAAH), and inhibitors of the enzyme were suggested as potential treatment for human cannabis dependence. However, the status of brain FAAH in cannabis use disorder is unknown. Brain FAAH binding was measured with positron emission tomography and In cannabis users, FAAH binding was significantly lower by 14%-20% across the brain regions examined than in matched control subjects (overall Cohens d 0.96). Lower binding was negatively correlated with cannabinoid concentrations in blood and urine and was associated with higher trait impulsiveness. Lower FAAH binding levels in the brain may be a consequence of chronic and recent cannabis exposure and could contribute to cannabis withdrawal. This effect should be considered in the development of novel treatment strategies for cannabis use disorder that target FAAH and endocannabinoids. Further studies are needed to examine possible changes in FAAH binding during prolonged cannabis abstinence and whether lower FAAH binding predates drug use.