Some stress is necessary for you to live a happy, normal, and peaceful life. Too much stress, on the other hand, can cause things like mood disorders, mental issues, and even changes in the physical structure of your brain. Most of these issues are the direct result of the overproduction of cortisol, a hormone your body creates in high volume when you feel stressed out. Here are seven ways stress affects the brain and the science to back them up.
Chronic stress causes the production of a hormone called cortisol to skyrocket. When this hormone is present in your body in large numbers, your body uses it to create a neurotransmitter called glutamate. You need some glutamate as a source of energy for your brain, but too much can lead to problems. In fact, per a 2006 study published in Dialogues of Clinical Neuroscience, glutamate creates a significant number of free radicals, which can damage your brain and even increase your odds of getting cancer.
Just like your skin sheds cells and creates new ones, your brain does much the same thing. It relies on BDNF, or brain-derived neurotrophic factor, to build those new cells. Cortisol, which is produced in high numbers when you’re chronically stressed, halts the production of BDNF. Per a 2010 study published in Neurobiology of Disease, this can not only prevent the growth of new brain cells, but it may also lead to mental conditions like schizophrenia.
Your body relies on a very important group of specialized cells, collectively known as the blood-brain barrier, to prevent the toxins in your blood from seeping into your brain before they can be filtered out by your kidneys and/or liver. An interesting 1996 study published in the British Medical Journal showed that stress may have a direct effect on the blood-brain barrier, making it more permeable. This is one of the most significant ways in which stress affects the brain. It can lead to brain cancer, infection, and perhaps even multiple sclerosis.
An interesting study published in Clinica Chimica Acta in 2013 showed that most elderly patients dealing with some form of cognitive impairment – whether or not it was related to dementia – had high levels of cortisol in their bloodstreams. This is one of the most well-studied ways in which stress affects the brain. These same researchers believe that reducing stress can reduce your chances of getting dementia, Alzheimer’s, and other similar neurological disorders in the future.
Back in 2009, researchers at Yale University conducted and published a study in which they measured the brains of 100 healthy individuals just before and just after extremely stressful events. They found that these patients’ brains – particularly their hippocampi, the areas of the brain related to the regulation of emotion and other physiological functions – shrunk quite quickly.
Inside your brain, there are specialized cells called microglia, which behave much like a standalone immune system that keeps your brain healthy. These microglia activate when your brain is exposed to an infection or toxin; they act much like a shield. Unfortunately, once they’ve been activated, they can’t be deactivated. A 2013 study published in Depression and Anxiety suggested that high levels of cortisol can turn on your microglia at an alarming rate, triggering inflammation that may ultimately lead to depression. In fact, stress affects the brain so acutely in this way, some researchers believe that inflammation may be the root cause of most clinical depression cases.
The fear center in your brain is called the amygdala. This part of your brain is especially sensitive to the effects of inflammation and cortisol. In fact, even as stress is shrinking your hippocampus, it’s also increasing the size of neural connections and the amount of activity level in your amygdala. This causes fear and anxiety, which can dominate every aspect of your life. It’s by far one of the most pronounced ways in which stress affects the brain.
Stress affects the brain both mentally and physically in many ways. With all of this in mind, it’s vital to learn to manage stress, whether you choose to meditate, make lifestyle changes, or even seek therapy from a professional. Doing so can improve your mood, reduce your risk of cancer, and even ward off things like dementia and Alzheimer’s disease. Read our article on 21 simple ways to reduce stress here.