In each instance where we face a potential threat, our minds and bodies go into action, mobilizing to either deal with the issues (fight) or avoid the problem (flight). You have probably heard all about how bad stress is for your mind and body. It can lead to physical symptoms such as headaches and chest pain. It can produce mood problems such as anxiety or sadness. It can even lead to behavioral problems such as outbursts of anger or overeating. What you might not know is that stress can also have a serious impact on your brain. In the face of stress, your brain goes through a series of reactions—some good and some bad—designed to mobilize and protect itself from potential threats. Sometimes stress can help sharpen the mind and improve the ability to remember details about what is happening. Let’s take a closer look at five of the most surprising ways that stress affects your brain. The researchers performed a series of experiments looking at the impact of chronic stress on the brain. They discovered that such stress creates more myelin-producing cells, but fewer neurons than normal. The result of this disruption is an excess of myelin in certain areas of the brain, which interferes with the timing and balance of communication. The researchers found that stress can also have negative effects on the brain’s hippocampus. For more mental health resources, see our National Helpline Database. The brain is made up of neurons and support cells, known as “gray matter” responsible for higher-order thinking such as decision-making and problem-solving. But the brain also contains what is known as “white matter,” which is made up of all the axons that connect with other regions of the brain to communicate information. White matter is so named due to the fatty, white sheath known as myelin that surrounds the axons that speed up the electrical signals used to communicate information throughout the brain. The overproduction of myelin that the researchers observed due to the presence of chronic stress doesn’t just result in a short-term change in the balance between white and gray matter—it can also lead to lasting changes in the brain’s structure. Psychologist Daniela Kaufer, the researcher behind these experiments, suggests that not all stress impacts the brain and neural networks in the same way. Good stress, or the type of stress that helps you perform well in the face of a challenge, helps to wire the brain in a positive way, leading to stronger networks and greater resilience. Chronic stress, on the other hand, can lead to an array of problems. “You’re creating a brain that’s either resilient or very vulnerable to mental disease, based on the patterning of white matter you get early in life,” explained Kaufer in a news release. The hippocampus is one of the regions of the brain heavily associated with memory, emotion, and learning. It is also one of the two areas of the brain where neurogenesis, or the formation of new brain cells, occurs throughout life. In experiments, the research team placed young rats in a cage with two older rats for a period of 20 minutes. The young rat was then subjected to aggression from the more mature residents of the cage. Later examination of the young rats found that they had cortisol levels up to six times higher than that of rats who had not experienced a stressful social encounter. Further examination revealed that while the young rats placed under stress had generated the same number of new neurons as those who had not experienced the stress, there was a marked reduction in the number of nerve cells a week later. So stress can kill brain cells, but is there anything that can be done to minimize the damaging impact of stress? “The next step is to understand how stress reduced this survival,” explained lead author Daniel Peterson, Ph.D. “We want to determine if anti-depressant medications might be able to keep these vulnerable new neurons alive.” While people often associate negative outcomes to sudden, intense stress created by life-altering events (such as a natural disaster, car accident, death of a loved one), researchers actually suggest that it is the everyday stress that we all seem to face that, over time, can contribute to a wide range of mental disorders. In one study, researchers from Yale University looked at 100 healthy participants who provided information about the stressful events in their lives. The researchers observed that exposure to stress, even very recent stress, led smaller gray matter in the prefrontal cortex, a region of the brain linked to such things as self-control and emotions. Chronic, everyday stress appeared to have little impact on brain volume on its own but may make people more vulnerable to brain shrinkage when they are faced with intense, traumatic stressors. “The accumulation of stressful life events may make it more challenging for these individuals to deal with future stress, particularly if the next demanding event requires effortful control, emotion regulation, or integrated social processing to overcome it,” explained the study’s lead author, Emily Ansell. One study found that chronic stress has a negative impact on what is known as spatial memory, or the ability to recall information the location of objects in the environment as well as spatial orientation. A 2014 study revealed that high levels of the stress hormone cortisol were connected to short-term memory declines in older rats. The overall impact of stress on memory hinges on a number of variables, one of which is timing. Research suggests that when stress occurs immediately before learning, memory can actually be enhanced by aiding in memory consolidation. On the other hand, stress has been shown to impede memory retrieval. For example, studies have shown that exposure to stress impairs memory retrieval in children. For example, some experts suggest that such research might play a role in the development of drugs designed to prevent the detrimental effects of stress on the brain.
