Psychoneuroimmunology

Psychoneuroimmunology is a concept that links the way we think and our physiology—our brain function and immune response.

Behavioral and psychological events can have a significant impact on the activity of the immune system.  Essentially, stress causes the same response in the immune system that the common cold does.  A person will experience the same symptoms as a result of stress that he/she would from a cold.

A professor at the University of Colorado, Steven Maier, PhD, attests that the immune system will send signals to the brain “that potently alter neural activity and thereby alter everything that flows from neural activity, mainly behavior, thought and mood” (Azar 2001: 34).  Not only can stress cause a person to become physically sick, but it can also initiate a shift in a person’s actions, thoughts, and moods.

Many psychoneuroimmunologists study T-cells, B-cells, and antibodies, which are part of the immune system.  Maier, on the other hand, studies the “nonspecific immune response”—or the response of the body within one hour to defend against infection or injury.  This response prompts many physiological changes in the body, such as fever, liver metabolism change, and release of cortisol.  It also causes behavioral changes, such as higher anxiety levels (Azar 2001).  The main purpose in these responses is to maintain energy levels in the body to fight the infection.

Maier explains how the signal arrives at the brain: “’Your macrophage [cells that are the first to arrive at the site of infection] chews on a bacteria, it releases interleukin-1 [a pro-inflammatory cytokine, which promotes inflammation at the site] into the neighboring space, the interleukin-1 binds to receptors on the paraganglia, which send neurotransmitters to activate the vagus nerve,’ which sends a signal to the brain” (Azar 2001: 34).

Stress also enters into this process, though it originates in the brain instead of the immune system.  Despite the difference in origin, it results in an increased level of interleukin-1 and the same responses that are associated with the nonspecific immune response mentioned above.  In fact, the response is so similar that Maier goes so far as to say that “stress is another form of infection” (Azar 2001: 34).

A study by Kiecolt-Glaser et. al. examined various factors that contributed to postsurgical healing.  It was found that greater anxiety before surgery resulted in a slower recovery afterward.  In fact, stress slows down wound healing between 24% and 40%.  Emotions affect the release of stress hormones, which influence the immune system.  People who have higher levels of anxiety will also experience more pain postsurgically, which can adversely affect immune function.  These factors contribute to a slower recovery time (Kiecolt-Glaser 1998).

This study also examined other social factors and how they affected healing following surgery.  For instance, increasing age results in slower recovery time.  Health behaviors also influence healing.  For example, risk factors, such as drinking alcohol and smoking, both cause a physiological effect in the body that slows down recovery (Keicolt-Glaser 1998).  It amazed me that social factors and stress could have such a significant impact on physical health.

My question for you all is this: What can you do to change the way you think and relieve the stress in your life so that you can avoid unnecessary harmful immune responses?

Resources:

1. Azar, Beth. 2001. “A New Take on Psychoneuroimmunology.” Monitor on Psychology, 32 (11): 34.

2. Kiecolt-Glaser, Janice K.; Page, Gayle G.; Marucha, Phillip T.; MacCallum, Robert C.; & Glaser, Ronald. 1998. “Psychological Influences on Surgical Recovery: Perspectives from Psychoneuroimmunology.” American Psychologist, 53(11): 1209-1218.