Chronic stress increases the stress hormone cortisol and affects many brain functions, putting you at risk for many mood disorders and other mental issues.
Stress is an unavoidable part of modern life.There are two main kinds of stress — acute stress and chronic stress — and not all stress is bad for you.Acute stress is the reaction to an immediate threat, commonly known as the “fight or flight” response.Once the threat has passed, your levels of stress hormones return to normal with no long-lasting effects.But chronic stress — the kind most of us face day in, day out — is a killer.
90% of doctors’ visits are for stress-related health complaints. Chronic stress makes you more vulnerable to everything from cancer to the common cold. The non-stop elevation of stress hormones not only makes your body sick, it negatively impacts your brain as well.When stress becomes chronic, it changes your brain’s function and even its structure down to the level of your DNA. Neuroscientists have discovered how chronic stress and cortisol can damage the brain. A new study reconfirms the importance of maintaining healthy brain structure and connectivity by reducing chronic stress.
Neuroscientists at the University of California, Berkeley, have found that chronic stress triggers long-term changes in brain structure and function. Their findings might explain why young people who are exposed to chronic stress early in life are prone to mental problems such as anxiety and mood disorders later in life, as well as learning difficulties.
It has long been established that stress-related illnesses, such as post-traumatic stress disorder (PTSD) trigger changes in brain structure, including differences in the volume of gray matter versus white matter, as well as the and size and connectivity of the amygdala. However, researchers are just beginning to understand exactly how chronic stress creates long-lasting changes in brain structure which affect how the brain functions.
In a series of revolutionary experiments, Daniela Kaufer, UC Berkeley associate professor of integrative biology, and her colleagues, discovered that chronic stress and elevated levels of cortisol can generate more overproduction of myelin-producing cells and fewer neurons than normal. Kaufer et al published their findings in the February 11, 2014 issue of the journal Molecular Psychiatry.
2012 Yale University studyshowed that chronic stress can actually reduce brain volume. In other words, if you are stressed out all the time, your brain just might shrink. Among its many effects, lower brain volume can lead to impaired cognition and hampered emotional function.
Why does this happen? According to the study, stress and/or depression activate a transcription factor known as GATA1, which regulates the genes that control synaptic connections. When fewer synaptic connections form, brain volume is lowered.
The good news is damage doesn’t have to be permanent, however. Brain volume can return to normal, according to the author of a 2000 brain volume study of people with post-traumatic stress disorder. When hormone levels in the brain return to normal, brain volume rebounds to normal size.
According to the University of Maryland Medical Center, stressful events activate the hypothalamic-pituitary-adrenal system, which release catecholamines – neurotransmitters such as dopamine, norepinephrine, and epinephrine. These chemicals activate the amygdala and suppress concentration, short-term memory, rational thought, and inhibition.
This suppression of normal brain responses allows you to engage fully in fight or flight without your brain intruding. Unfortunately, suppression of such responses over the long-term can also harm your memory and impair cognitive function.
The “gray matter” of the brain is densely packed with nerve cell bodies and is responsible for the brain’s higher functions, such as thinking, computing, and decision-making. But gray matter is only half of the brain matter inside our heads—the other half of brain volume is called white matter.
White matter is comprised of axons, which create a network of fibers that interconnect neurons and creates a communications network between brain regions. White matter gets its name from the white, fatty myelin sheath that surrounds the axons and speeds the flow of electrical signals between neurons and brain regions.
“We studied only one part of the brain, the hippocampus, but our findings could provide insight into how white matter is changing in conditions such as schizophrenia, autism, depression,suicide, ADHD and PTSD,” Kaufer said. The hippocampus regulates memory and emotions, and plays a role in various emotional disorders and has been known to shrink under extended periods of acute stress.
The researchers found that hardening wires, may be at the heart of the hyper-connected circuits associated with prolonged stress. This results in an excess of myelin—and too much white matter—in some areas of the brain. Ideally, the brain likes to trim the fat of excess wiring through neural pruning in order to maintain efficiency and streamlined communication within the brain.
One of the most worrying effects of stress on the brain is that it increases your risk for dementia and Alzheimer’s. Being diagnosed with Alzheimer’s disease is the #1 health fear of American adults, even more so than cancer.Alzheimer’s is now the sixth leading cause of death.One in three US seniors will die with Alzheimer’s or other forms of dementia. And it’s the most expensive disease in the country. There is no simple “magic bullet” to prevent Alzheimer’s.
The ‘stress hormone’ cortisol is believed to create a domino effect that hard-wires pathways between the hippocampus and amygdala in a way that might create a vicious cycle by creating a brain that becomes predisposed to be in a constant state of fight-or-flight.
Chronic stress has the ability to flip a switch in stem cells that turns them into a type of cell that inhibits connections to the prefrontal cortex, which would improve learning and memory, but lays down durable scaffolding linked to anxiety, depression, and post-traumatic stress disorder.
Take Care of Yourself
Understanding stress and its effects on your brain can help you protect yourself. In a very busy world where stress is the norm rather than the exception, it’s important you seek to mitigate stress using any technique that works for you. Your brain manages all of your bodily functions, so it’s important you protect it.