How Stress Affects Our Brain, Minds and Lives

Related Articles:
The 10-Part Stress Series
Previously in this Series: The Effect of Stress on our Bodies

One of the main problems with treating mental illness has stemmed from how society has viewed it.

Instead of viewing it as the result of physical problems in the brain, mental illness has too frequently been seen as the result of personal weakness.

Other diseases used to be viewed in a similar manner.

In the 1960s, a diagnosis of cancer was seen as shameful. Most patients and families kept cancer diagnoses quiet. When cancer in the family was discussed, it was in hushed tones and the information was clearly not to be shared. The cause of cancer was unknown and a diagnosis was seen as a personal failing.

Until 1982, stomach ulcers were also seen as a disease caused by behavior. Doctors and patients thought stress caused ulcers – not in the sense that we think of stress today but in the sense of being a stressed-out, nervous sort of person. The prescribed cure was rest, an extremely bland diet and as little stress as possible. When Australian doctors discovered that ulcers were caused by helicobacter pylori, a type of bacteria, it took 10 years for the global medical establishment to accept that to be the case.

Today, we understand that cancer is caused by cells dividing uncontrollably rather than personal behavior, and that ulcers can be cured with antibiotics. But we still consider ‘mental illness’ to be connected to behavior and, too often, personal failing.

Heart disease, kidney disease, liver disease – these are all seen as medical issues that require medical attention and treatment. But mental illness is too often seen as something that one can and should cure on their own. A diagnosis of mental illness still carries stigma and shame.

In The Effect of Stress on our Bodies, we saw that chronic stress causes chronic inflammation. Together, chronic stress and chronic inflammation play a significant role in the onset of severe psychiatric conditions like depression, bipolar disease, PTSD and other anxiety disorders.

A far better description for these illnesses would be ‘brain disease’ instead of ‘mental illness’ because they are significantly based in physical changes occurring in the brain rather than in “wrong thinking”.

Chronic stress and inflammation: the attack on the brain

In the previous article, we learned that stress causes adipose tissue (body fat) to secrete Interleukin-6 (IL-6). IL-6 is a pro-inflammatory protein that stimulates T-cells and B-cells, leading to chronic inflammation. IL-6 plays a critical role in inflammation of neural tissues in the brain and nerves. Diseases like Alzheimer’s, multiple sclerosis and Parkinson’s are strongly associated with increased levels of IL-6 in the brain.

Endothelial cells line the interior surface of blood vessels in the human body. These cells regulate and control the flow of fluids and substances in and out of the tissues that make up the body. The blood-brain barrier (BBB) is a specialized system of endothelial cells lining blood vessels in the brain. The BBB shields the brain from toxic substances, supplies the brain with nutrients, and filters unwanted substances back into the blood. The BBB provides critical protection for the brain.

Over time, chronic inflammation causes the BBB to become “leaky” – allowing in substances that should not be allowed in the brain. Additionally, cells of the immune system can directly infiltrate the BBB. That provides a mechanism through which inflammatory proteins can enter the brain directly.

Today, inflammation in the brain is closely tied to degeneration of the brain. Inflammation can cause great damage to parts of the brain that control behavior, personality, memory, language and movement. This brain damage plays a powerful role in the diseases mentioned above as well as dementia and other brain illnesses.

The hormones directly associated with chronic stress also damage the brain. Chronic exposure to cortisol and corticotropin releasing factor (CRF) can cause shrinkage of the hippocampus – an area of the brain critical for learning and memory. Chronic levels of these hormones are also associated with mood disorders, possibly by altering serotonin levels. Serotonin helps regulate our mood and our feeling of being well.

The brain damage caused by chronic stress and inflammation can cause many different problems in our minds and in our lives.

The problems they cause can appear to us as personal failing or weaknesses when, in fact, they may well be based on changes in brain chemistry and brain structure.

How chronic stress affects our minds

Chronic stress has frequently been associated with anxiety but the mechanism behind this was unknown. New research is implicating inflammatory-induced damage and changes to the limbic system and associated prefrontal structures.

The limbic system includes a variety of brain structures, including the amygdala and the hippocampus. We’ve previously seen that chronic stress can cause damage to the amygdala and chronic inflammation is tied to neural damage in the brain.

The limbic system is associated with many critical parts of our identity and behavior, including:

• Learning, memory, and recall (especially about emotional experiences)
• Emotion
• Our sense of smell
• Aggressive behavior
• Defensive behavior

Structures in the prefrontal cortex of the brain that connect to the limbic system provide conscious control over some aspects of the limbic system, including goal-directed behaviors.

Given how important these basic attributes of human life are, it’s not surprising that problems with the limbic system and associated parts of the prefrontal cortex can have far-reaching impacts on our minds and bodies. Some of the chronic problems associated with structural changes in the limbic system include:

• Chronic fatigue
• Depression
• PTSD and other anxiety disorders
• Panic attacks
• Hyperventillation
• Worry and Rumination
• Addictions
• Changes in libido
• Memory loss

Inflammatory-induced damage to other parts of the brain is associated with problems with:

• Motivation
• Mental Agility
• Biased Cognitive Processing
• Cognitive Problems

Biased cognitive processing associated with inflammatory-induced damage to the brain is always biased toward the negative.

In other words, inflammation in the brain causes damages that leads people to have more negative outlooks on life and the world around them and to view change with suspicion.

Cognitive problems caused by inflammation in the brain can include:

• Searching for words
• Forgetfulness
• Mental Slowness
• Confusion
• Constant Worrying
• Difficulty Concentrating
• Difficulty thinking in a logical sequence

Chronic stress and pregnancy

It is now established that chronic inflammation in pregnant women can affect the development of their babies, especially during the first half of pregnancy. The effects appear to be tied to high levels of IL-6 and other pro-inflammatory cytokines in the mother’s body.

Studies have suggested that chronic inflammation in the mother can affect the organization of brain structures in their baby, with effects ranging from reduced working memory to potentially greater chances of chances of developing psychological problems later in life.

How chronic stress affects our lives

The wide-ranging ways in which chronic stress and chronic inflammation can alter and damage structures in our brains can clearly cause many problems with our minds and our thinking. These can then lead to life problems.

For example, chronic stress hormones can play havoc with our sleep. Cortisol is involved in controlling our sleep-wake cycles and regulating our 24-hour cycles. But cortisol is also associated with stress. Chronic stress raises cortisol levels, which affect our ability to go to sleep. High levels of cortisol also affect our ability to reach deep, restorative sleep. Together these can cause:

• Insomnia, or problems getting to sleep
• Problems staying asleep
• Fatigue

The problems associated with damage to our limbic system and the prefrontal areas associated with it can result in a lower libido or sex drive, which can lead to serious relationship problems. Other problems associated with damage to these brain structures include:

• Reduced sense of humor
• Increased rage
• Greater irritability
• Increased argumentation

These changes, along with the cognitive problems described above, can result in:

• Fewer social connections
• Decreased contact with family and friends
• Poor relationships with work colleagues
• A sense of loneliness
• Avoiding others/they avoid you because of crankiness

Changes in the limbic system can lead to various addictive behaviors, including the abuse of or addiction to:

• Alcohol
• Prescription or illegal drugs
• Nicotine
• Food
• Sex
• Gambling
• The Internet

Besides personal isolation, the above can lead to:

• Less Exercise
• Less time spent on hobbies or interests
• Migraines and headaches

The Bottom Line

Chronic stress causes chronic inflammation. Both are associated with many of the leading causes of death and other diseases. Chronic stress and chronic inflammation also change and damage our brains and our nervous systems.

The damage to our brains caused by stress and inflammation has wide-ranging effects on our minds, our emotions and our behaviors. Our ability to learn, think and remember can all be diminished by this brain damage.

Emotional changes resulting from brain damage can range from increased worry to serious anxiety disorders and depression. The outward expressions of these can reduce our ability to interact normally with other people and lead to relationship problems, isolation and loneliness. Addictive behaviors resulting from changes in our brain can become destructive to our sense of self, our families, our careers, our incomes and our ability to lead independent lives.

Suggested Reading:
The 10-Part Stress Series
Next in this Series: Coping With Stress