There’s no silver lining here, so let’s just dive into it: have a lot of chronic stress in your life? You’re at greater risk of developing a mental illness.
This comes to us by way of a study published in Molecular Psychiatry. Your brain is composed of grey matter and white matter. Grey matter is largely neurons, which store and process information, and glia, which are support cells. White matter is composed of axons, the cells that connect the neurons; white matter is so named for a fatty sheath of myelin surrounding the axons. The balance between the types of cells is fairly delicate, and unfortunately, chronic stress causes the brain to produce more myelin processing cells and fewer neurons than normal. This results in an excess of myelin in some parts of the brain, throwing off communication within the brain.
How bad is communication disrupted? According to Daniela Kaufer, one of the study’s co-authors, “You can imagine that if your amygdala and hippocampus are better connected, that could mean that your fear responses are much quicker, which is something you see in stress survivors. On the other hand, if your connections are not so good to the prefrontal cortex, your ability to shut down responses is impaired. So, when you are in a stressful situation, the inhibitory pathways from the prefrontal cortex telling you not to get stressed don’t work as well as the amygdala shouting to the hippocampus, ‘This is terrible!’ You have a much bigger response than you should.”