Antidepressant treatment using selective serotonin reuptake inhibitors (SSRI’s), such as escitalopram or fluoxetine, is a common first line offensive against depression and anxiety in today’s medicine, but what happens when they don’t work? This is the reality for a large proportion of individuals taking SSRI’s to treat their depression. Many individuals show little-to-no improvements in their mood and symptoms, effectively termed a “treatment resistant” population. The Salmaso lab at Carleton University in conjunction with the Child Study Center at Yale University has recently published a research article in PLOSone about a certain treatment resistant population using a mouse model. The mouse model used in the study was genetically engineered so that it does not produce a growth factor, called fibroblast growth factor-2, or FGF2.

 

In humans, lower levels of FGF2 have been found in the hippocampus, an area of the brain that is important in the formation and storage of memories and also has been implicated with major depression. Some mutations in the FGF2 gene, those that can change the structure and function of the growth factor, in humans have been found to leave the individual as a member of the treatment resistant population. Using the mouse model, the researchers were able to show that without FGF2, using fluoxetine, or more commonly known as Prozac, does not help reduce the symptoms of depression and depressive behaviours.

 

This study offers an exciting look into the elusive treatment resistant population and allows us to step closer and closer towards

 

For a more detailed look at the findings, check out the full paper here. (Open Access)