Chronic stress causes harmful long-term changes in brain; exercise to avoid stress, stay happy and healthy

(http://newscenter.berkeley.edu) Chronic stress generates long-term changes in the brain that may make people more prone to mental problems, such as anxiety and mood disorders, according to researchers from the University of California, Berkeley.

Doctors have already known that people suffering from post-traumatic stress disorder (PTSD) and other stress-related problems have brain abnormalities like differences in the amount of gray matter versus white matter. But this new work helps scientists as they try to discover how those changes are made.

Daniela Kaufer, UC Berkeley associate professor of integrative biology, and her colleagues found through a series of experiments that chronic stress causes the body to produce fewer neurons and an excess of myelin, white matter, "which disrupts the delicate balance and timing of communication within the brain," according to UC Berkeley's press release.

The researchers focused only on one part of the brain called the hippocampus, which plays a role in various emotional disorders and regulates memory and emotions, but their results could have wide-reaching implications for conditions such as schizophrenia, autism, depression, suicide and PTSD.

Kaufer's findings could explain how stress is related to some changes in brain connectivity, for example, in people with PTSD. "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," she said. Other connections, such as to the prefrontal cortex, which moderates responses, might not be as strong, so the ability to shut down responses is impaired, leading people to have much larger responses than they normally should.

The decreased number of neurons could also explain how chronic stress affects learning and memory.

Kaufer is continuing her research on the effects of stress on the brain, as well as different therapies to treat that stress, including exercise and antidepressants. Some natural methods to help mitigate chronic stress include finding times to laugh, gardening, enjoying time outside and exercising, which can include biking, walking, hiking, rock climbing or anything else that's fun or takes your mind off of stress. Yoga and meditation are great ways to deal with stress too.

The study is titled "Stress and glucocorticoids promote oligodendrogenesis in the adult hippocampus" and was published in Molecular Psychiatry.