High and sustained levels of stress not only increase blood pressure, lower immunity and inflammatory response but also affect the brain itself.
In a previous post we reported that long-term exposure to cortisol (the “stress hormone”) can result in damage to cells in the hippocampus, a brain structure crucial for memory formation. A recent study at Yale now shows that experiencing stressful life events can reduce gray matter in other critical regions of the brain that regulate emotions and important physiological functions.
The team of researchers conducted magnetic resonance imaging scans of 103 healthy subjects between the age of 18 and 48 (68% were male). All the participants had previously been interviewed about traumatic stress and adverse life events, such as the death of a loved one, loss of a home to natural disaster, job loss or divorce.
Brain scans showed that higher levels of cumulative stress were associated with less gray matter in several regions of the prefrontal cortex (at the front of the brain, behind your forehead) and the limbic system. These regions of the brain regulate our emotions and help us control our impulses (self-control). They also regulate a few physiological functions such as blood pressure and glucose levels. Even the brains of subjects who had only recently experienced a stressful life event showed markedly lower gray matter in these areas.
Less gray matter means less brain cells to support the functions of the damaged areas. In this case, increasing stress exposure is associated with less gray matter in regions involved in emotion regulation and impulse control. This suggests that people who experience or have experienced adverse life events and high levels of stress may then be more vulnerable to depression, addiction, and other stress-related psychopathology.
In other words, because the reductions in gray matter impair brain function, the body is less prepared to respond to stressful situations. In addition, since the regions involved also control our physiology, implications for long-term health are also at stake.
Fortunately the brain is plastic and can also change for the better. Dealing early on with the stress response and/or the events that trigger the stress may help decrease the long-term effects of the stress on the brain. Meditation, physical exercise and social interaction, which all have a positive impact on the brain, are a few things to consider when trying to manage one’s stress.
Ansell, et al. (2012). Cumulative Adversity and Smaller Gray Matter Volume in Medial Prefrontal, Anterior Cingulate, and Insula Regions. Biological Psychiatry, published online Jan 5th 2012.