Mice genetically developed to lack the ability to produce serotonin in their brains did not display any depression-like symptoms or behaviors, according to a study in ACS Chemical Neuroscience. The finding “puts into doubt the long-standing belief that a deficiency in serotonin — a chemical messenger in the brain — plays a central role in depression,” stated a press release from the journal.
The researchers from John D. Dingell VA Medical Center and Wayne State University School of Medicine found that serotonin-depleted mice “were compulsive and extremely aggressive, but didn’t show signs of depression-like symptoms.” They also found that, when put under stress, the serotonin-depleted mice “behaved in the same way most of the normal mice did.”
Though overall treatment with antidepressants did not seem to alter or help the serotonin-depleted mice in any way, the researchers found that a small subset of the mice “responded to treatment with SSRIs in the same manner as wild-type controls with significant reductions in immobility time on the tail suspension test, indicative of antidepressant drug effects.”
According to the press release, the findings “suggest that serotonin is not a major player in depression.”
New study throws into question long-held belief about depression (ACS Chemical Neuroscience Press Release, August 27, 2014)
Mice Genetically Depleted of Brain Serotonin Do Not Display a Depression-like Behavioral Phenotype (Angoa-Pérez, Mariana et al. ACS Chemical Neuroscience. Published online August 4, 2014. DOI: 10.1021/cn500096g)