A new study suggests that the protective layer surrounding nerve cells may play a role in the development of certain types of mental illness. Known as the myelin sheath, this nerve fiber is recognized as being connected to the development of multiple sclerosis, but the recent study furthers prior research which also connects myelin layers to mental illness. The study demonstrated how environmental factors like social isolation influence myelin production and can therefore contribute to certain psychological conditions. A recent article on Psych Central explained just how myelin production is influenced by environment. It discussed the biomedical sciences study in which mice were subjected to periods of isolation in order to see how myelin production would be impacted. The researchers used samples of brain tissue to measure myelin presence before and after isolating the mice. The mice were kept alone for a period of eight weeks after which time researchers noted a change in social behavior in the mice. Their tissue samples also revealed a corresponding lessening of myelin. The study showed how being socially deprived reduces the production of myelin in the prefrontal cortex of the brain. The prefrontal cortex is responsible for cognition and emotion. Without sufficient myelin, cell communication is interrupted and behavioral changes take place. The mice with less myelin showed signs of social withdrawal. This is consistent with what is known about myelin's effect on multiple sclerosis, as that condition is often accompanied by depression. Less myelin is also associated with mental illnesses such as anxiety, autism, and schizophrenia. All of these conditions are characterized by social withdrawal behavior. Knowing that a person's lack of social interaction triggers a lowering of myelin production which then leads to social maladjustment is important. Until pharmaceuticals are developed which can stimulate myelin production, keeping affected patients engaged in social interaction is one way to prevent further symptoms. The layer which protects the nerve cells also protects emotional well-being.