Volunteers Given Marijuana Drug to Help Study Anxiety
THC reduces the response to threat in a specific portion of the brain. Volunteers were given delta-9-tetrahydrocannabinol (THC), the active ingredient in marijuana, and shown photographs of emotional faces, which represented signals of social communication. Results, of brain scans showed that THC reduces the response to threat in a brain region called the amygdala. This allowed researchers to locate a part of the brain that could serve as a good place to look at for anti-anxiety drug activity.
The goal of researchers at University of Michigan Medical School is to see if they can tailor drug treatments for anxiety to an individual patient now that an anxiety related portion of the brain has been identified. Follow up studies will investigate the responses that different patients with different genes for brain neurotransmitter activity (serotonin) respond to the drug Zoloft (sertraline), a selective serotonin reuptake inhibitor.
Genes for different versions of proteins that transfer serotonin (a neurotransmitter in the brain) are expected to have different sensitivity to the SSRI drugs ( Zoloft ) which are commonly used to treat depression and anxiety.
THC, the active compound in marijauna was used because it mimics the effects of naturally occuring brain chemicals called endocannabinoids. The human brain uses the endocannabinoids in a variety of ways that are not fuly understood. One role of the endocannabinoids is to act on serotonin receptors, and play a role in sensing anxiety and fear. Endocannabinoids also play a role in other brain activities such as pain perception.
Ref: Journal of Neuroscience, March 5, 2008, Vol. 28, No. 10, 2313-2319
