5 Effects Of Stress on The Brain
For many of us, it’s difficult to imagine a day without stress. It occurs throughout our day, coming from our work lives, our home lives, and sometimes even our social lives. Although some levels of stress seem to be an unavoidable part of modern living, there are significant adverse effects on the brain’s overall health, particularly with chronic stress.
1- It changes the structure of the brain
Within the brain, we have gray matter and white matter. Gray matter is composed of neurons and unmyelinated cells and is largely responsible for actions such as decision-making and problem-solving. It surrounds the white matter, which is made up of axons covered in a white fatty material known as myelin. These myelinated cells connect other brain regions together, facilitating communication. White matter is responsible for coordinating the action potential in our brain.
When our brain experiences chronic stress, the myelin composition in our white matter. The myelin production actually increases while the neurons’ in our gray matter decreases. This creates an imbalance in communication, causing things like slower decision-making or problem-solving. It can also directly impact the amygdala and the hippocampus, leading to volatile moods. These changes can be long-lasting, and in some cases, permanent.
2- Increases the susceptibility to mental diseases
Stress in the brain is actually a result of hormones. When we experience what we know as stress, our brain releases the stress hormone cortisol. Cortisol itself isn’t bad. It’s part of our sleep-wake cycle and is part of our sympathetic nervous system or our fight-or-flight response.
The problem is when our stress levels remain consistently high. This means a nearly constant release of cortisol that never has a chance to release. These excess levels disrupt many different areas of normal brain functionality such as interrupting our ability to fall and stay asleep, interfering with the release of feel-good chemicals in our brains, and disrupting synaptic communication. The combination of these effects can lead to anxiety, depression, PTSD, among other mental disorders.
3- Affects the memory
There have been numerous studies done to understand the link between stress and memory. Stress has been directly linked to negative spatial memory, a decline in short-term memory, and problems with memory retrieval and retention. This has a direct impact on learning, along with other cognitive functionality.
When we undergo mild or moderate amounts of stress, our brain releases corticosteroids. These signal the amygdala to communicate with the hippocampus. The combination takes information and encodes it with emotion, helping to consolidate the memory. But when our brain is flooded with these hormones for extended durations, it disrupts these communication pathways and can potentially damage the hippocampus. This makes it difficult to form new memories.
Stress also disrupts the communication between the hippocampus and the prefrontal cortex, which is responsible for memory retrieval. That’s why we tend to draw a blank in high-stress situations. Finally, stress interferes with our sleep cycles, which is when memory moves from short-term to long-term. Without healthy sleep, our memories can’t move into our long-term stores and we lose them.
4- Disrupts focus and concentration
Stress in small bursts can actually help improve our focus and concentration. When we undergo stress, our brain releases small amounts of adrenaline. This in addition to cortisol, gives us the energy we need to buckle down and get things done. Ever had a surge when facing a deadline? That’s this power combo at work.
The problem occurs when we experience stress in high quantities for long durations. After a while, our brain gets fatigued. We require higher levels of the hormones that gave us that initial boost, and our brain can’t produce them at the levels we would need. As we tire, our focus and concentration begins to fade. The longer we attempt to force our attention on a task, the more stress we begin to feel, and we tend to fall into a cycle where our stress hormones spike but our brain struggles to respond.
5- Heightens our emotional responses
Stress is linked directly to our sympathetic nervous system, triggering our fight-or-flight reflex. When it’s operating normally we can make decisions faster, use the burst of energy to accomplish our task, and have higher levels of focus as well. And because this reflex is often triggered when we’re scared or threatened, the amygdala is a key part of our stress response.
The amygdala is where many of our emotional responses take place, including fear, anger, and anxiety. Chronic stress actually strengthens the amygdala by constantly feeding this fear and anxiety response. Stress also increases activity in our ventromedial prefrontal cortex, the area involved with emotional cognition. This can enhance fears, reducing input from the more logical cognitive areas. At the same time, stress reduces the serotonin in our brain, making it difficult for us to regulate our moods.
Stress in small doses is a valuable part of our sympathetic nervous system. It is linked with our fight-or-flight reflex and helps us make heightened decisions quickly and efficiently. However, chronic stress can be damaging to our mental health as well as our overall brain health. It’s important to be aware of how stress can impact our focus, thought process, and influence our moods so that we can work to find ways to alleviate stress in our daily lives.