Chronic Stress Can Impair Your Memory
Cortisol is the hormone associated with stress that increases the brain's ability to encode and recall traumatic events. Excessive release of this hormone can cause chronic stress, which can then lead to memory impairment or mental illness.
According to neuroscientists at the University of California, Berkeley, chronic stress can initiate long-term changes in the brain through the development of white matter. Too much white matter can change the way circuits are connected in the brain and result in poor communication between neurons.
The chemical imbalance that stress causes could affect the brain and make it more susceptible to mental illnesses, including short-term memory loss as well as forms of dementia. White matter structure defects have also been associated with depression, schizophrenia, bipolar disorder, obsessive-compulsive disorder, and post-traumatic stress disorder.
Neuroscientists have found that low levels of anxiety can affect the brain's ability to recall memories, whereas high levels of constant or incessant anxiety can result in the development of white matter and lead to further brain defects. "White Matter in Learning, Cognition and Psychiatric Disorders" was a study published by the National Institutes of Health and it documents the brain's concentration of white matter and how it affects the development of various disorders.
The UC Berkeley neuroscientists used mice in their experiments and made some other discoveries. They stressed out the rodents by either immobilizing them in a straitjacket for three hours per day for seven days, or they injecting them with corticosterone. The results they found were alarming because rat and human brains possess some striking similarities. The rats' brains were unable to produce oligodendrocytes, which insulate and support axons, or nerve fibers that are the primary transmission lines of the nervous system.
"When we looked afterwards at their brain, we saw there was a decrease in the amount of neurons made from those cells (oligodendrocytes)," said Daniela Kaufer of UC Berkeley, the lead investigator of the study, in this LA Times article.
The UC Berkeley study, "Stress and Glucocorticoids Promote Oligodendrogenesis in the Adult Hippocampus," was published in the journal Nature and could help neuroscientists revolutionize how certain mental ailments are prevented and/or treated.