For several years now, mental health researchers have been studying new rapid-acting antidepressants such as ketamine and scopolamine to treat severe depression. The benefit of these medications is that they treat depression symptoms in hours as opposed to weeks, as is typical for most antidepressants currently on the market.
"One of the biggest problems in the treatment of depression today is a delay in onset of therapeutic effects. There has been a great need to discover faster-acting drugs," said, Stephanie Dulawa, Ph.D., Associate Professor of Psychiatry and Behavioral Neuroscience at the University of Chicago, who used her second NARSAD Young Investigator Grant for this study. In a paper published Oct. 29th in Molecular Psychiatry, Dr. Dulawa and her team report on a new potential class of fast-acting antidepressants that appear to be more suitable for human use with fewer side effects.
In seeking a new class of fast-acting therapeutics, Dr. Dulawa and team tested biological pathways previously shown to generate antidepressant effects that had never been studied for rate of onset of symptom alleviation. They looked at different subtypes of serotonin receptors, proteins that are binding partners for serotonin, a neurotransmitter that has been shown to regulate mood, memory and appetite. Of these subtypes, serotonin 2C receptors stood out.
When these 2C receptors were selectively blocked in mice, a reduction in depression-like behaviors in five days was observed compared to a minimum of two weeks for a control antidepressant medication.The researchers believe that this new biological mechanism could offer a much safer alternative to ketamine and scopolamine. The team is now investigating methods of testing the blocking of these 2C receptors that will be suitable for clinical trials.