Chronic Stress is Changing Your Brain

Stress is a fact of life, and we know that. But modern women are more anxious than ever, and somewhere along the line we began to accept it—some of us even thrive on it. Research has shown that chronic stress can lead to physical changes in the regions of the brain that are responsible for higher-level-processing—learning, memory, decision-making and emotional regulation, which could explain, in part, why were feel so frazzled and emotional when we’re under pressure.

We’ve already seen, in a slew of studies, that patients with chronic mental illness tend to have higher ratios of white matter to grey matter in cortical regions of the brain, although researchers were unsure of which came first. Newer discoveries draw a more specific connection: when rodents were exposed to long periods of stress, their brain matter in the hippocampal region began to show the same ratios of white versus grey matter as those found in patients with mental illnesses like severe depression, anxiety and PTSD. But what’s the connection, and what does it mean?

Daniela Kaufer, Ph.D., is an associate professor at the University of California, Berkeley and a fellow of CIFAR, the Canadian Institute for Advanced Research. Her in-depth studies of neurological development and brain health may shed light on the importance of preventing chronic stress, or at least keeping it in check.

“Stem cells in the brain generate new neurons throughout our lives,” she explains. These are the cells that facilitate learning and memory processes. But following a severe chronic stressor, these stem cells appear to follow a new path. Instead of facilitating the birth of new grey matter—neurons—these stem cells produce a new kind of cell that gives rise to white matter—a substance called myelin that serves to speed up communication between the neurons we already have. In other words, for better or for worse, it seems that chronic stress can change the way our brain communicates. And these changes make our physical brain appear more similar to that of subjects diagnosed with stress-related mental illnesses. So, does one lead to the other? We don’t exactly know yet.

“It’s important to remember that this is the hypothesis,” Kaufer explains. “But do we ever see abhorrent myelination or too much myelination in one place? The answer is yes, and we see this in patients with mental illnesses like severe depression, PTSD, etc., so we know that patterns of myelination do change in relation to mental functions.” More studies need to be completed before a detailed causal effect can be determined, but the correlation between stress and these structural changes in the brain are very real, and Kaufer intends to discover what this really means for us.

Kaufer suspects that these changes might lead to a stronger fight-or-flight response when we do experience a stressor, which would have been a helpful survival tool throughout evolution. Today? Not so much. Since a correlation between stress and the development of mood disorders is well documented, learning to exercise control over our stress levels, or at least how we deal with them, could help to prevent a vicious cycle down the road.

Current practices of mindfulness-based stress reduction such as therapy, yoga and other meditational practices have shown incredible results in treating patients with stress-related health problems. But, so far, we can’t tell if this will reverse the effects on the brain. “Right now, we don’t have any way to track these hippocampal stem-cell changes in humans,” says Kaufer, and this is due to the invasive nature of the studies, but she points out how strongly she believes that these methods can help. “We can make the connection,” she explains. “If you look at all the other signs of stress effects, all of them are very well mitigated by yoga and meditation and mindfulness. [Researchers] have looked at cortisol levels, immune responses, pain management, cardiovascular disease risk assessment…all of these things seem to be so much better [after a stress-intervention strategy].” But it’s certainly something that women of today seem reluctant to do because, unfortunately, there just isn’t enough time.

“I teach a course called the Neurobiology of Stress,” says Kaufer, “and during the semester I go through all of the biology of the stress response, and the science, and then we talk about interventions…but I tell them that I’m the worst example.” She says, “I know how important it is [to take time for yourself], and I should be doing better, but life just trumps it. You feel like you have to be a perfectionist.”

Although we can’t (or won’t) do anything to change our busy lifestyles, the secret to keeping our minds healthy could be in taking those few minutes a day to look after ourselves. And it’s time to take that more seriously. Our brains literally depend on it.