A University of Michigan Medical research team is exploring the link between brain activity, genetics and medication to find out better anxiety treatments for those who do not benefit much from medicines prescribed by the doctor.
K. Luan Phan, M.D., and his former colleagues at University of Chicago came out with intriguing findings from a brain imaging study in occasional, non-dependent, marijuana users.
The findings were made in a placebo-controlled design, after giving the volunteers delta-9-tetrahydrocannabinol (THC), the active ingredient in marijuana, and exposing them to photographs of emotional faces, which served as signals of social communication.
The results indicated that THC reduces the response to threat in a brain region called the amygdala, and this made the researchers to come down on an area of the brain that may act as a potential target for new anti-anxiety drugs.
In order to search for more clues as to how anxiety treatment could be tailored to the individual patient, to give the best chance that a treatment will work for him or her, Phan is set to conduct a new clinical trial, which is currently seeking participants.
This new study will involve testing a generic form of the drug Zoloft (sertraline), a selective serotonin reuptake inhibitor (SSRI) approved by the U.S. Food and Drug Administration for social anxiety disorder and other anxiety disorders. Both people with social anxiety disorder and a comparison group of people without anxiety are needed for brain scanning and genetic testing.
The main purpose behind this study is to see if variations in the genes for certain brain receptors and transporters are linked with variations in how a person's brain reacts to pictures of emotional faces, and variations in how they respond to the anti-anxiety drug.
And this would ultimately guide the researchers towards an individualized or personalized approach to medical care.
"These two studies are trying to get to the same goal: to find better treatments for anxiety disorders that affect millions of Americans and seriously interfere with their functioning," says Phan, an assistant professor of psychiatry at U-M and the VA Ann Arbor Healthcare System.
"The cannabis study highlights a new avenue that we need to explore further as we try to develop novel medications, while the sertraline study will try to find out if we can tell which patients might or might not respond well, and by what mechanism, to an already existing medication known to have some efficacy in treating anxiety disorders," he added.
The study was published last month in the Journal of Neuroscience.