Stress-Effects on the Immune System and Psychological Disorders - Dissertation Example

STRESS-IMMUNE SYSTEM, PSYCHOLOGICAL DISORDERS Stress-Effects on the Immune System and Psychological disorders Not all stress is bad. The right amount of stress is beneficial to the body but when the body is constantly exposed to negative stressors, it affects the health of the individual. Stress causes changes that weaken our immune system and as a result, health can be negatively affected. In this scenario, infections and illnesses can flare up. In people who have been diagnosed with psychological disorders, stress seems to have a detrimental effect and knowledge regarding measures to avoid stress and manage the different external stressors should be imparted to the caregivers as well as the sick themselves. Stress-Effects on the Immune System and Psychological Disorders The word ‘stress’ has different implications for different people. The layman defines it as tension, unpleasant external force or an emotional upheaval. Psychologists have defined stress in different ways. The most commonly used definition of stress was developed by Lazarus and Launier (1978) who regarded stress as a transaction between people and the environment with interaction between stressor and distress. (Ogden, 2000). Cannon’s fight or flight model(1932) was one of the earliest models which proposed that external threats elicited a fight or flight response which were accompanied by physiological changes. Seyle’s General Adaptation Syndrome (GAS) was developed in 1956 and had three stages in the stress response, the first being the ‘alarm stage’, the second the ‘resistance stage’ and the third being the ‘exhaustion stage’. These two models regarded the individual as automatically responding to an external stressor. Holmes and Rahe (1967) developed the SRE theory (Schedule of Recent Experiences) which was the life event’s theory which related stress to different life events which act as stressors (Ogden, 2000). In the 1970s, Lazarus introduced the model of appraisal and transaction between the individual and the environment. From then on, the understanding of the stress response from a psychological point of view developed (Ogden, 2000) Stress causes autonomic and behavioral changes. Autonomic changes are due to increased sympathetic activity and stress induced behavioral changes vary from a minor startle to major changes like a major depressive disorder or a post traumatic stress disorder. For a long time now, the effects of stress on the immune system have been studied. The effects of stress on the immune system are complex and depend on the nature of the stress, on the individual and also on the duration and intensity of stress. The predominant effect of acute stress on the immune function appears to be suppression while the consequences of chronic stress are poorly understood. Repeated mild stress may enhance immune function and auto immune diseases are worsened by stress. (Buckingham, Gillies, Cowell, eds., 1997). Researchers have known that behavioral and psychological events can influence immune systems. Stress and infection sensitize the body’s reaction to them, a stress primes the body so that an exaggerated response to infection occurs and vice versa is also true. Stress and infection activate overlapping neural circuits involving Interleuken-1 as the mediator. (Azar, 2001) Acute stressors of short duration lasting a few minutes were associated with potentially adaptive up regulation of few parameters of natural immunity and down regulation of some functions of specific immunity. Brief natural stressors suppress cellular immunity, preserving humoral immunity. Chronic stressors suppress both. In few cases, physical vulnerability as a function of age or disease increases vulnerability to immune change. (Segerstram, Miller, 2004). Three pathways via which stress can affect the immune system. a. Sympathetic fibers which end on the lymphatic tissue (spleen, lymph nodes, bone marrow, thymus). These fibers release substances that act on the immune system. b. The hypothalamic-pituitary-adrenal axis, sympathetic-adrenal-medullary axis, secretes hormones, peptides that bind to receptors of cells of the immune system. c. Behavioral responses to stress like alcoholism, insomnia can modify immune systems. Immunological activation in mammals results in a ‘sickness behavior’ which includes behavioral changes, reduced activity, depressed mood and anorexia. Acute stress enhances and chronic stress suppresses the immune system according to Dhabhar and McEven (1997). (Segerstrom, Miller 2004). Acute stressors cause an up regulation of natural immunity reflected by increased number of neutrophils, cytokines (IL-6, IFNgamma) and NK cells in the peripheral blood and down regulation of specific immunity shown by decreased proliferation. Brief natural stressors like an examination have an effect on functions like increased humoral immunity. They decrease the Th-1 response, IFNgamma which is responsible for natural and cellular immune functions and increased Th-2 response (IL-6 and IL-10). IL-6 stimulates natural and humoral immune functions and IL-10 inhibits the Th-1 response (Segerstrom, Miller 2004). Older age increases the vulnerability to stress-related immune changes. Stressful event sequences are not reliably associated with changes in immune functions. They do cause an increase in the number of circulating NK cells with non-significant increases in natural and specific immunity. Stress can weaken immune systems interfering with the body’s natural defenses. Infections and diseases occur more frequently and take a longer time to heal. A study found high levels of IL-6 in elderly caregivers which hinders immune function contributing to arthritis, heart disease, etc. The stress of caregiving caused IL-6 levels to increase four times as quickly in eczema, psoriasis, oral and genital herpes, ulcerative colitis and Crohn’s disease. When inflammation occurs, cortisol and other glucocorticoid hormones start an anti-inflammatory reaction and stress interferes with the immune system’s capacity to respond to these hormones. (The Effect of Stress on the Immune System, 2005). Chronic stressors like taking care of a demented spouse, long term physical disability have negative effects on the immune system. Both natural and specific immunity were affected negatively as well as the Th-1 and Th-2 responses causing global immunosuppression. Distant stressors which occurred in the remote past do not affect immunity significantly. Life events (bereavement, trauma) cause a significant reduction in the number of NK cells and a marginal reduction in the number of T-cytotoxic lymphocytes. Bereavement results in decrease in NK cell cytotoxicity and trauma was found to decrease the number of T-cells in the blood. Studies which focused on general appraisals and intrusion thoughts as stressors did not find a significant effect on immunity (Segerstrom, Miller 2004) Seyle’s findings (1975) suggested that stress globally did affect the immune system and provided the first model for the link between the two. Increasing stressor duration results in change from adaptive changes in immunity to detrimental changes, initially occurring in cellular immunity and later on in the immune function in general. Aging and HIV positivity cause a decrease in immune function and make an individual more vulnerable to the negative effects of stress on their immune function (Segerstrom, Miller ,2004). Psychoneuroimmunology(PNI) studies the link between psychological stresses and its effect on immune function. It studies psychology, immunology, neurosciences and the interaction between these sciences. In an interview with Psychiatric Times, Ronald Glaser, professor of molecular virology, immunology and medical genetics, defined psychoneuroimmunology as a “field that studies the interactions between the central nervous system, endocrine system and immune system, the interactions of behavior/stress on these interactions and the implications for health of these interactions.” (Kaplan, Arline, 1999). In humans and in animal models, Glaser et al have found that stress markedly delays wound healing. While most interventions are behavioral, only one pharmacological intervention is begin explored. Andrew H. Miller et al at Emory University School of Medicine, conducted a double-blind, placebo-controlled trial in which pretreatment with placebo or paroxetine for two weeks was done. Paroxetine treated patients showed lower levels of depression and fewer symptoms on the neurotoxicity rating scale which measures depression, anxiety, memory problems, withdrawal, isolation and also muscle aches, pain, nausea, vomitings and vision changes. Studies similar to this one on other drugs have not been carried out and thus pharmacology still does not play a significant role here. (Kaplan, Arline, 1999). Chronic psychological stress reduces the immune system’s reaction to hormonal secretions which normally fight the inflammatory response. Mood and positive attitude increase the ability of immune system to fight disease. In humans, stressful events like examinations, wars, bereavement, insomnia, divorce, care giving are associated with decreased immune function. Apart from stress, factors like anger, anxiety and depression can affect the immune system. Any event which affects the autonomic nervous system activity or hormonal activity thus affects our immune system. (Irwin et al, 1987). Stress also has an effect on psychological disorders. Stress causes increased activity of the glucocorticoid hormone and this causes a decrease in the norepinephrine levels causing slowing in attentiveness and sluggishness. For example in schizophrenics, surgery is a stress and healing times are increased as compared to the general population. Depression affects the immune system indirectly by having an effect on the lifestyle of the person. (Beaton, 2003). Effects of stress on psychological disorders: Children of parents with psychiatric disorders like schizophrenia and manic depression have a greater risk of stress related problems. Persons who suffer from intense prolonged stress have worried thoughts, high anxiety levels and intrusive disturbing thoughts.Stress occurs when the adaptive capacity of the individual is overwhelmed by events. Stress is subjectively defined and response to stress is a function of one’s personality (Eisendrath, Lichtmacher, 2005). Stress can produce different reactions in a person. Common subjective responses are fear, rage, guilt and shame. Acute stress that is reactivated in patients diagnosed with anxiety or stress related psychological disorders is manifested by restlessness, irritability, fatigue, increased startle reaction, feeling of tension. Post traumatic stress disorder patients on exposure to stress experience physiological, hyper arousal, startle reactions, intrusive thoughts, illusions, insomnia, nightmares, impulsivity, difficulties in concentration, hyperactivity. Patients who have been diagnosed with psychological disorders like anxiety, panic disorders, schizophrenia, bipolar disorder exhibit elevated stress response behavior and agitation.(Eisendrath, Lichtmacher, 2005). Acute exposure to stress causes negative health related behaviors. Being ill with a physical illness or more so a mental illness is itself a stress. Stress following this illness has further negative implications for the health of these individuals. (Ogden, 2000). In sick patients, stress causes an exacerbation of the illness. If the illness is appraised as being stressful, this can in turn decrease the chances of recovery. (Ogden, 2000). Deficits in immunity are associated with psychiatric disease. Decreased immune function was found in depressed patients as measured by mitogenic stimulation and NK cytotoxicity. There is a strong association between depression and elevated cortisol levels and immune deficits in depression can be related to this hypercortisolemia. Depression has also been correlated with a hyperactivity of noradrenergic system, hence cortisol or NE could be responsible for the immunosuppression. Early studies found evidence of reduced immune function in schizophrenics but this has not been substantiated in later studies. (Dunn, J. Adrian, 2000). Patients may develop anxiety after exposure to extreme traumatic events. This reaction may occur shortly after the trauma (acute stress disorder) or be delayed and subject to recurrence as in post traumatic stress disorder(PTSD). These patients often avoid stimuli or stressors that precipitate recollection of the trauma and demonstrate an increase in vigilance, arousal and startle response. Patients with exposure to chronic stress are at risk of developing disorders like mood disorders, anxiety disorders and substance abuse. In PTSD, there is excessive release of norepirephrine from the locus coerulus in response to stress and increased noradrenergic activity at projection sites in the hippocampus and amygdala. Greater sympathetic cues and responses occur in response to stress in these patients. (Kasper L., Dennis et al, 2005) Patients of OCD (Obsessive Compulsive Disorder) have obsessive thoughts and compulsive behaviors. Stressors increase anxiety in these patients and effective techniques to treat them include increased exposure to stressful situations to get them to have a normal response to stressors. (Kasper L., Dennis et al, 2005) A number of studies on emotional and personality factors, causes of autoimmune diseases like rheumatoid arthritis and Crohn’s disease revealed the role of stress in their causation. Arthritics were found to be quiet, introverted, conscientious, restricted in expression, self sacrificing, sensitive, over-active and vulnerable to stress. The onset of disease in them often follows a period of psychological stress. Failure of adaptation to stress and inability to cope with new stressors causes progression of disease. (Buckingham, Gillies, Cowell, 1997). According to M. Roberts in ‘Psychology Today’, “Good moods corresponded to a bolstered immune response, better enabling the body to reject the substance, minor daily mood fluctuations are associated with immune functioning. Research has repeatedly shown that extreme stress and depression can weaken the body’s ability to fight off potential invaders but now it seems that even daily ups and down can toughen the task of the immune system.” (Shoaf, L. Norman, 1989). Allergies like urticaria, atopic dermatitis, allergic rhinitis and asthma are related to the effects of stress. One study found that 75% of people with allergic disorders show both immunological and psychological disturbances. Mental well-being has a protective influence on those with genetically determined immunologic disease predisposing factors. (Buckingham, Gillies, Cowell, 1997). Reducing the effects of stress: Identifying the aspects of life that cause stress is the first step in reducing the effects of stress on immunologic as well as psychological factors affecting disease. Living a more balanced life by sharing responsibilities at home and work, being assertive, taking on work that you are confident of completing, organizing time, eating a healthy diet, having friends and family gatherings are among habits that cultivate a stress free life. (Dumke, Hutman, Segal, 2005). Getting enough sleep of about 7-8 hours daily has a profound impact on stress levels, immune function and disease resistance. Sleep time is when the immune system does repairs and rejuvenation and a chronic lack of sleep can leave us feeling lethargic, irritable and forgetful and to have a difficulty concentrating and makes us incapable of coping with daily stressors. Having a positive attitude counteracts the negative impact of stress, tension and anxiety on the immune system and well-being. (Gilbert, N. Monique, 2005). Managing time, accepting support seeking help when needed, developing coping skills for stress relief are necessary. Organize and simplify life, practice relaxation techniques and avoid tension and take a break from pressures of work to reduce stress. High nutrient diet rich in antioxidants, omega-3 fatty acids, folate and vitamins A,C,E controls hypertension, heart disease, stroke, depression, inflammatory and auto-immune disorders. Regular tea drinking can strengthen the immune system. L-theanine is a beneficial amino acid in green and black teas which increases the infection fighting capacity of gamma delta T-cells and promotes general well-being by influencing the release of neurotransmitters like dopamine, serotonin, GABA. (Gilbert, N. Monique, 2005). Seeking professional help is important when stress causes anxiety or depression. The beneficial effects of stress are short-lived. Hence, chronic stress has to be tackled and help from psychologists and psychiatrists is to be taken. (Dumke, Hutman, Segal, 2005). Lifestyle changes with a diet rich in variety of vegetables, fruits and fish oil, Vitamin C rich food and avoidance of alcohol, caffeine and tobacco with an exercise regimen comprising of brisk walking, swimming, yoga relieves stress. Making a plan and executing it is also a stress management technique. Regular exercise and physical activity strengthens the immune system and lowers cholesterol, blood pressure, cortisol and other stress hormones. (Gilbert, N. Monique, 2005). CBT (Cognitive Behavioral Techniques): They are effective ways to reduce stress. Identification of the source of stress, restricting priorities, changing one’s response to stress and evaluating suitable methods for managing and reducing stress from its various components. (Stress, About Health and Fitness, 2005). Laughter and humor reduce stress hormones like adrenaline and cortisol. Laughing also benefits the immune system by increasing the number and activity of Natural Killer T-cells, which act as the first line of defense against viral attacks and damaged, dead cells. Music and soothing sounds reduce tension, blood pressure and promote feelings of tranquility. (Gilbert, N. Monique, 2005). Looking after your body, a healthy diet, adequate rest, relaxation techniques like deep breathing exercises, meditation, yoga, therapeutic massages which loosen taut muscles and a positive attitude are all stress busters. Stress management needs continuous practice throughout life. Learning how to better cope with demands in your environment is the goal. Stress has effects on almost every system in the body. (Stress, Mayo Clinic, 2005). Adopting relaxation methods causes a natural unwinding of the stress response and decreases the effects of stress on the immune function. Relaxation has physiological effects like lowering of blood pressure, reduction of tension and easing up of emotional strains. In a study of children and adolescents with adjustment disorder and depression, a combination of massage, yoga, relaxation techniques to release muscle tension effectively reduced both feelings of anxiety and stress hormone levels. (Stress, About Health and Fitness, 2005). Acupuncture, hypnosis, deep breathing exercises, muscle relaxation, meditation, massage therapy are few other methods for relieving stress. Stress avoidance and management techniques should be taught to the sick as well as to their caregivers. 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