“Our bodies are gardens; our wills are our gardeners.” – Othello, William Shakespeare
Throughout history of medicine and psychology, various relationships have been put forth to explain the initiation and degenerative progression of biological disorders, and their relationship to attitude, stress, and mental health. In “Psychoneuroendocrinology effects of the immune system”, George Solomon highlights many historic perceptions in examples: Native American medicine utilizing balance of life forces; George Day, phthisiologist (pulmonary tuberculosis physician), cited necessity of unhappiness to allow infection by pulmonary tuberculosis; and later Robert Ader’s full encompassment of the “relationship of stress, emotion, immunological dysfunction, and physical and mental disease” (Solomon, 1981). Psychoneuroimmunology (PNI) is defined as the study of how psychological processes work with the nervous and immune systems; it examines the interaction between these processes. To phrase it more directly, it studies how a person’s stress levels can change the maintenance of their health and the recovery process of their body.
Current researchers, such as Janet Kiecolt-Glaser and her associates, are studying how various levels of stress affect the process of healing and outcome of treatment (Kiecolt-Glaser, et al, 2002). Proinflammatory cytokines have been associated with healing processes, whereas stress can be demonstrated to cause slower healing of physical wounds. The cytokines have significant effect on various medical conditions associated with aging, including cardiovascular disease, osteoporosis, arthritis, Type 2 diabetes, certain cancers, Alzheimer’s disease, and periodontal disease. In the research, there is a demonstrated correlation between depression, anxiety, and prolonged or chronic infections correlated indirectly to proinflammatory cytokine. “Chronic inflammation has been suggested as one key biological mechanism that may fuel declines in physical function, leading to frailty, disability, and, ultimately, death” (Kiecolt-Glaser, et al, 2002). The cytokines play a major role in tissue repair and protecting the wound from infection. They also are important in activating the clearing of the wound site and stimulating the cells that provide subsequent repair. The cytokines appear in reduced levels at wounds of stressed individuals (Alford, 2007).
K. Mašek brought together many of these ideas. Mašek targeted MDP (muramyl dipeptides, promotes or inhibits sleep) to single neurons in cortex, hypothalamus, and hippocampus (Mašek, et al, 2000). By targeting these specific areas, Mašek was able to identified three circuits involved in immune response. The first structure decreased immune response; and the second structure increased immune response. The third structure interconnected these others, and a lesion here modulated the immune response. These studies are also examining how these processes interact by way of a greater understanding of the central nervous, neuroendocrine, and immune systems. The systems operate on a two-way street, a bidirectional communication.
For me personally, I have lived my life with the expectation of being healthy and highly immune to infections. My attitude about resistance to infection affects this greatly. I am currently employed with the State of Arizona; and, as one of the employment benefits, I receive approximately 3.7 hours of medical leave every two weeks. In my fifteen years with the State, I have accumulated over 1,000 hours available medical leave. This accommodates me with twenty-five weeks off work on medical leave; but this also demonstrates that, over my fifteen years in employment with the State, I have only used approximately 150 hours of medical leave. This also includes family sick leave, to care for sick family members, and dental and medical appointments. My resistance cannot be contributed to lack of exposure. Over my time of employment, I have had numerous instances of exposure to various forms of illnesses, minor as they may be. My coworkers have nearly exhausted their available medical leave. So, because of their limited available leave, they often remain in the office through the onset of colds and influenza viruses; and return as soon as physically possible. These occurrences bring greater exposure during commonly infectious periods for many bacteria. In many cases, these coworkers seem to spread these illnesses within the office. Fortunately, for me, I have great immunity to the colds and other ailments to which they expose me, or maybe it is all in my head.
For the most part, PNI first came into use about 30 years ago with Robert Ader’s introduction of the concepts. With improved technology and increase availability of experiment data, we are entering a phase of tremendous growth potential in how we understand our biological systems and how they interact with our brains. In the future, we will see development of treatments for diseases based on, not only how our body protects itself from the disease, but also how our mind understands what is happening to us. This could resembled a medically prescribed happy-pill; eliciting specific hormonal or cytokine responses that change how the disease will progress or cease to progress. “When we better understand how mind and body fight for survival we will have a better chance to develop new drugs which could influence this fight for the benefit of patients” (Mašek, et al, 2000).
Ader, R., Cohen, N., & Bovberg, D. (1983). Immunoregulation by behavioral conditioning. Trends in Pharmacalogical Sciences, 4, 78.
Alford, L. (2007). Findings of interest from immunology and psychoneuroimmunology. Manual Therapy 12, 176-180
Gerrig, R. J., & Zimbardo, P. G. (2010). Psychology and life. Boston: Pearson Education Inc.
Kiecolt-Glaser, J., McGuire, L., Robles, T., Glaser, R. (2002) Psychoneuroimmunology: Psychological influences on immune function and health. Journal of Consulting and Clinical Psychology, 70(3), 537-547
Mašek, K., Petrovický P., Ševčík, J., Zídek, Z., Franková, D. (2000). Past, present and future of psychoneuroimmunology. Toxicology, 142, 179–188.
Solomon, G. (1981). Psychoneuroendocrinological Effects on the Immune Response. Annual Review of Microbiology, 35, 155-184