A new Yale study shows that stress can reduce brain volume and function, even in otherwise healthy individuals.
Researchers from the Yale Stress Centre analysed the effect of experiencing stressful life events. The study, published January 5th in the journal Biological Psychiatry, concluded that stress can decrease the amount of grey matter in the brain and make it more difficult for people to manage stressful situations in the future. It also may aid effects to prevent stress-related disorders through screening and vigilance.
According to Rajita Sinha, program director for the Yale Stress Centre and professor of psychiatry at the Yale School of Medicine, the study is unique in analysing a healthy human population. While past studies have demonstrated that stress reduces brain volume in animals and psychiatric samples of patients, Sinha said that the study is the first to show the impact of cumulative stress on the brain in otherwise healthy subjects.
Study candidates completed psychiatric and physical health assessments that pre-screened the population for substance abuse and head injuries, among other factors. Each of the 103 healthy participants then participated in a cumulative adversity interview that estimated the degree of stress in their life through questions about “traumatic” and “recent” occurrences, such as as parental divorces and financial crises.
Researchers compared the results of the interview to magnetic resonance imaging scans of participants’ brains and determined that higher levels of cumulative stress were associated with less grey matter in the prefrontal cortex.
“We found that the accumulation of stressful life events was affecting key regions of the brain,” said Emily Ansell, assistant professor of psychiatry at the Yale School of Medicine and author of the study. “These key regions are the regions we believe regulate our emotions, help us control our impulses and help us process our daily experience. They also control our physiology. These regions have implications for long-term health.”
Researchers also determined that the changes in brain volume can serve as warning signs for future mental and social disorders, and chronic diseases. Sinha said that because the reductions in grey matter impair brain function, the body is less prepared to respond to stressful situations.
Sinha stated that the study may help in preventative treatment for stress-related disorders, such as depression and drug addiction. In the same way that doctors can treat people with high insulin levels to prevent diabetes, Sinha said that the study could enable doctors to monitor patients at risk for stress-related disorders.
“It’s difficult to think of any disease in which stress cannot play an aggravating or causative role,” Paul Rosch, president of the American Institute of Stress, wrote in an email to the News. Rosch added that the paper confirmed previous studies on the negative effects stress has on the prefrontal cortex.
Bruce Compas, professor of psychology at Vanderbilt University, said that anything that leads to a reduction in the number of connections between neurons, such as a decrease in grey matter, hurts the brain’s ability to store information and respond quickly to the environment. He also commended both the design and measurements of the study.
“So much of the function of different organ systems is really related to what we do to ourselves, to our behaviour and the choices we make.” said Sinha. “This is very exciting to us and to the field because it opens up testing and interventions for brain-related disorders.”
Sinha and her fellow researchers at the Yale Stress Centre are now looking to find potential moderators that could potentially reduce the negative effects of cumulative stress on the brain.