New Discovery Could Change Future Diagnosis and Therapy of Depression

A team of researchers from the Chicago College of Medicine at the University of Illinois have recently discovered a biological protein marker for depression. Specifically, when a protein called Gs alpha activates adenylyl cyclase, it activates certain neurotransmitters (such as serotonin or dopamine) through signal transduction. The change in location of this protein in the brain is what determines how much neurotransmitter is actually released. This is because in depressed patients, proteins (such as the signaling protein Gs alpha) are located in viscous, sticky areas of the cell known as lipid shafts. These shafts impede the communicating ability of Gs alpha, thus reducing its capacity to activate adenylyl cyclase for signal transduction. When this happens less dopamine and serotonin reach the brain, unless the Gs alpha protein is freed from the lipid shafts by anti-depressants.

This discovery will allow a straightforward laboratory test to determine the effectiveness of an antidepressant treatment. This research study, which was presented in the March 12^th issue of Journal of Neuroscience, will allow patients to find out whether the anti-depressant treatment they have started is successful in only four to five days, as opposed to four to five weeks.

Mark Rasenick, distinguished professor of physiology, biophysics, and psychiatry stated that this discovery could help millions of patients who have received unsuccessful treatment or are simply undiagnosed for depression. Rasenick and his team of researchers compared certain brain samples of depressed people who committed suicide to people with no psychiatric disorders, and although both had the same amount of Gs alpha in the brain, the depressed patients had a far greater amount located in lipid shafts. This research could also help with the discovery of biochemical pathways involving anti-depressants and why they take a great deal of time to have a significant effect.