Compounds that restore certain brain signals were found to reverse depressive symptoms in less than 24 hours, according to a new study by researchers at University of Maryland School of Medicine. If further testing proves successful, the compounds could offer significant advantages over current antidepressant medications.
Researchers believe the compounds appear to reverse symptoms of depression in rats by strengthening communication in certain regions of the brain. The researchers were surprised to see results in less than 24 hours, as opposed to the weeks it takes for antidepressant drugs to work for patients.
Despite there being more than a dozen antidepressants on the market, their effectiveness is relatively low. In a major study of 4,000 patients, about 31 percent of patients go into remission after 14 weeks and 65 percent after six months. The National Institute of Mental Health said these results are modest considering 30 percent of patients report relief from depression when taking a placebo.
Further, the most commonly used antidepressant drugs, selective serotonin reuptake inhibitors (SSRIs), take two to eight weeks for the drugs to take full effect. Because many people don’t get relief with their first medication, they may endure months of treatment trials, with no guarantee of remission.
Rather than looking at serotonin, the researchers looked at how brain activity is determined by a balance of excitatory and inhibitory communication between brain cells. The researchers focused on inhibitory messages sent by a compound called GABA and sought a way to limit these messages and increase excitatory messages, a deficiency of which may cause depression. They used compounds, called GABA-NAMs for their study.
“These compounds produced the most dramatic effects in animal studies that we could have hoped for,” said lead author Scott Thompson, Ph.D., chair of the department of physiology at the University of Maryland School of Medicine, in a press release. “It will now be tremendously exciting to find out whether they produce similar effects in depressed patients. If these compounds can quickly provide relief of the symptoms of human depression, such as suicidal thinking, it could revolutionize the way patients are treated.”
After exposing the rats to mild chronic stress and inducing the animals into exhibiting depression-like behaviors, they were given GABA-NAM, compounds which reduce GABA messaging in the brain. Within about 24 hours, researchers said they could see signs of depression disappear in the rats.
The researchers believe that the compounds may be a safer treatment than ketamine, which is undergoing study as a possible antidepressant. Ketamine, in off-label trials, has been found to reverse depressive symptoms in a matter of hours.
Ketamine is controversial because it has psychoactive properties and has been abused as a street drug, “Special K.” The drug is not approved by the FDA for depression and its longterm effects are unknown.
The study is published in Neuropsychopharmacology.
