Asthma is a reversible obstructive respiratory disorder that produces impaired breathing, which may be accompanied by other respiratory symptoms, such as wheezing, coughing, and tightness in the chest. Asthma afflicts many millions of individuals around the world. In the United States, about 17 million people suffer from asthma, and morbidity and mortality rates for the disease are rising. Over 5,000 Americans die of the disorder each year, with mortality rates being higher among the elderly than younger individuals, among Blacks than Whites, and among people from lower than higher social classes; these rates are increasing particularly rapidly among children. Although asthma may emerge at any age, most people who develop asthma have their first episode in early childhood.
The respiratory symptoms in asthma episodes result mainly from temporarily decreased diameters of the airways to the lungs. Asthma is a psychophysiological disorder, and its development and episodes are best understood from a biopsychosocial perspective, involving the interplay of biological, psychological, and social factors in the person’s life.
Biomedical Factors in Asthma
During an acute episode of asthma, the airways narrow because they become inflamed, the smooth muscles of the bronchial tubes develop spasms, and the walls of the tubes constrict and produce mucus, which tends to plug the airways. These events result in part from arousal of the autonomic nervous system at the start of and during an episode in reaction to triggers, or precipitating conditions. There are three types of triggers: (1) environmental conditions, such as temperature and allergic substances; (2) physical activities, such as strenuous exercise; and (3) personal factors, such as current infections and emotions or moods. Because emotions arouse the autonomic nervous system, they may produce the initial symptoms in an attack or aggravate existing symptoms as a vicious circle develops.
When an asthma episode is triggered, a chain reaction occurs in the body. For example, when the trigger is an allergen, such as pollen, the immune system reacts with an overproduction of antibodies, which bind to mast cells found throughout the body that break down and release the chemical histamine, a highly reactant form of acetylcholine. In individuals who do not have asthma, histamine has relatively little effect on respiratory function, but in people with asthma, it causes the lining of the bronchial tubes to constrict markedly and secrete excess mucus. Autonomic nervous system activity appears to be mediated by activity in the vagus nerve, which arises from the medulla and connects to and regulates the heart, lungs, and airways by carrying efferent signals via the autonomic nervous system.
Although researchers do not fully understand the etiology of asthma as a disorder, it is known that environmental and genetic factors can play substantial roles in asthma development. An important environmental factor in asthma is respiratory infection. Past respiratory infection has been associated with the development of asthma, and current respiratory infections are major triggers of asthma episodes. There is also considerable evidence that heredity affects the development of asthma. Studies of twins have found much higher concordance rates among identical (monozygotic) than fraternal (dizygotic) twins for the presence of asthma. Family history studies have shown that the relatives of children with asthma have higher asthma prevalence rates than the relatives of children without asthma. Some evidence from research with twins indicates that heredity affects not only the presence of asthma, but also the severity of children’s asthma condition and the impact of respiratory infection and physical exertion as triggers of asthma episodes.
Medical treatment for asthma involves advising patients to avoid known triggers and to use medication of two types. First, anti-inflammatory medicines, such as cromolyn and corticosteroids, prevent asthma attacks from starting because they keep the airways open by reducing inflammation. Second, bronchodilators relax airway muscles, thereby stopping asthma episodes once they begin.
Psychosocial Factors in Asthma
Research findings and theory have implicated emotional and cognitive processes in the expression of asthma symptoms. Three lines of evidence have linked emotion and asthma. First, survey and interview data indicate that stress and emotion can trigger asthma episodes. Second, studies comparing individuals with and without asthma have found that those with asthma express more emotion when stressed and report greater amounts or degrees of negative emotion in their everyday lives. Because emotions arouse the autonomic nervous system, they may produce the initial symptoms in an asthma episode or aggravate existing symptoms. Despite some inconsistencies in the evidence, most research results support a role of emotions in triggering or exacerbating asthma symptoms.
The role of emotion in asthma suggests that cognitive processes may affect asthma episodes, and these processes have been implicated in both research and theory. Studies have shown, for example, that asthma symptoms can be induced in people who do and do not have asthma via suggestion under placebo conditions, such as inhaling an inactive substance. Thus, individuals with and without asthma who were told that the substance they would inhale would make breathing difficult showed far greater airway resistance while inhaling than people not told the substance would impair breathing. Studies demonstrating that emotion and suggestion can serve as triggers of attacks clearly implicate learning processes in the expression of asthma symptoms. This may occur through respondent (classical) and operant conditioning: respondent conditioning may establish nonallergic conditioned stimuli through association with allergic conditions; operant conditioning enables the reaction to persist via reinforcement processes (e.g., a parents attention when his or her child shows respiratory symptoms).
Another important issue is nonadherence to the medical regimen. Many people with asthma do not avoid triggers or take anti-inflammatory medicines as recommended, making attacks much more likely.
Psychological Treatments for Asthma
Because of the role that conditioning processes appear to play in asthma, efforts to apply psychological approaches have focused on using behavioral methods, which apply principles of operant and respondent conditioning, as adjunctive therapies to medical treatment for the disorder. These methods include relaxation, biofeedback, and systematic desensitization.
Relaxation techniques are muscular and nonmuscular activities that enable people to reduce their levels of emotional and autonomic arousal, which aggravate asthma episodes. The most commonly used muscular relaxation technique is called progressive muscle relaxation, which involves having people sit or lie quietly and focus their attention on specific muscle groups while alternately tightening and relaxing these muscles. Non-muscular relaxation techniques use “mental” or cognitive activities, such as meditation, in which individuals spend quiet periods focusing their awareness on a single thing, such as their breathing or a phrase, and autogenic training, which involves quietly focusing attention on internal sensations, such as how light or warm parts of the body feel. People generally need much practice to master relaxation techniques. Many studies have examined the value of relaxation methods in treating asthma and found them to be useful, especially if emotions play a strong role in triggering or worsening episodes. The evidence is stronger and clearer for muscular than nonmuscular methods.
Biofeedback is a technique by which individuals can acquire voluntary control over a physiological function by monitoring its status. The feedback the person receives for physiological functioning may be conveyed with high or low numbers on a gauge, pitches or degrees of loudness of tones from an audio speaker, or degrees of brightness of a light. Biofeedback for asthma may be applied in two ways. Respiratory biofeedback uses an apparatus to provide feedback regarding airflow to help people learn to control their respiration, particularly by enlarging airway diameters. Nonrespiratory biofeedback provides feedback on muscular activity, such as of the forehead, without directly affecting respiration. Studies on the value of respiratory and nonrespiratory biofeedback in treating asthma have produced inconclusive results, with effects being more positive for child than adult asthmatics. This age difference may reflect a generalized ability of children to use biofeedback more effectively than adults.
Systematic desensitization is a respondent conditioning technique for reducing fear or anxiety, replacing it with a calm response by pairing feared objects or situations with pleasant or neutral events, usually with the person employing relaxation techniques. The feared stimuli are presented in a graded series, or stimulus hierarchy. In asthma treatment, for example, the person might imagine or listen to increasingly more fearful descriptions of asthma attacks and various sensations and thoughts. Research has shown that systematic desensitization is a useful technique in treating asthma in children and adults and is more effective than relaxation alone. These studies have usually found large improvements, sometimes even at long-term follow-up, in subsequent symptoms.
In summary, biological, psychological, and social factors affect asthma development and episodes. Respiratory biofeedback, relaxation, and systematic desensitization methods can provide effective adjunctive approaches to medical treatment for asthma, but the utility of nonrespiratory biofeedback is less clear. Respiratory biofeedback is the only behavioral method for treating asthma in which success seems to depend on the patients age, with children seeming to benefit more than adults. The fact that behavioral methods have not always produced consistent and large (clinically meaningful) group-wide improvements in research may be partly because treatment groups included patients who varied widely in the role of emotions in their condition. Other promising treatment approaches that use psychological methods are hypnosis and asthma education programs, which train people with asthma to understand the disorder, use medications correctly and as scheduled, cope better with stress, and apply breathing and relaxation exercises when attacks begin.
References:
- American Lung Association. Asthma medications and Focus: Asthma. Retrieved (July 23, 2002) from www.lungusa.org
- Asthma and Allergy Foundation of America. Asthma & allergies. Retrieved (July 23, 2002) from www.aafa.org
- Devine, E. C. (1996). Meta-analysis of the effects of psychoeducational care in adults with asthma. Research in Nursing and Health, 19, 367376.
- Lehrer, P., Feldman, J., Giardino, N., Song, H.-S., & Schmaling, K. (2002). Psychological aspects of asthma. Journal of Consulting and Clinical Psychology, 7ft 691-711.
- Lehrer, P. M., Isenberg, S., & Hochron, S. M. (1993). Asthma and emotion: A review. Journal of Asthma, 30, 5-21.
- Sarafino, E. P. (1997). Behavioral treatments for asthma: Biofeedback-, respondent-, and relaxation-based approaches. Lewiston, NY: Mellen.
- Sarafino, E. P., & Goehring, P. (2000). Age comparisons in acquiring biofeedback control and success in reducing headache pain. Annals of Behavioral Medicine, 22, 10-16.
- Wright, R. J., Rodriguez, M., & Cohen, S. (1998). Review of psychosocial stress and asthma: An integrated biopsychosocial approach. Thorax, 53, 1066-1074.
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