Stress and the Brain

by: Ali Goldfield, M.A.

We all have stress in our daily lives. So much so that we often think nothing of running from place to place, eating on the go, and juggling work and family life. You have probably already heard that stress can wreak havoc with our immune systems, our sleep patterns and our ability to enjoy the things we used to, but did you know that stress can actually affect the size of your brain? 

Researchers know that trauma can significantly affect brain structure but one study done by researchers at Yale University now shows that everyday stressors, like a divorce, job loss, the death of a loved one or a serious illness can also affect our brain in the same way that one traumatic event can. These cumulative stressors, it seems, can lead to shrinkage in our brains, reducing the volume of grey matter and lowering our ability to further cope with adversity and may even lead to self-destructive behaviours such as addiction, overeating and depression. 

Past studies have shown that the stress response involves a brain region known as the amygdala, which sends out signals alerting us to any kind of threat. This results in the release of hormones, including cortisol, which prepare us for the flight or fight response to fend off the threat. Prolonged exposure to cortisol can cause brain neurons to shrink and it also interferes with their ability to send and receive information efficiently. This is just another piece of the puzzle in how prolonged stress can impair our ability to think and act in creative, flexible and healthy ways.

And it’s not only about stress shrinking our brains. In another study from Yale University, researchers compared the genetic makeup of donated brain tissue from deceased humans with and without major depression. Scientists found that only the depressed patients’ brain tissues showed activation of a particular genetic transcription factor, or “switch” that basically stops the genes from communicating. This lack of communication leads to a loss of brain mass in the prefrontal cortex. The scientists hypothesized that in the depressed patients’ brain, prolonged stress exposure led to disruption of brain systems. The depressed brains appeared to have more limited and fragmented information processing abilities. This finding may explain the pattern of repetitive negative thinking that depressed people exhibit. It’s as if their brains get stuck in a negative groove of self-criticism and pessimism. They are unable to envision more positive outcomes or more compassionate interpretations of their actions.

While the evidence is not conclusive, it makes a pretty good argument that stress and mental health issues that lead to stress do kill off our brain cells through the damaging effects of cortisol and through the disruption of the genes that facilitate neuronal connections. This shrinkage affects our cognitive abilities, our focus and our ability to concentrate. Since much in our lives is beyond our control, how can we prevent this type of cumulative stress from affecting our ability to deal with what life throws at us? 

The most important thing to remember is that the brain is plastic, meaning that there are ways to reverse the negative impact of stress on the brain. With the right tools and techniques, like meditation, exercise, proper diet (think Omega-3s), yoga and by maintaining strong social and emotional relationships, we can, in fact, counterbalance the damaging effects of stress and stop our brains from shrinking.

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