The Psychological Theories about Pain - Essay Example

The Psychological Theories about Pain Introduction Pain is a common complaint in medical settings. It may be defined as an unpleasant sensory or emotional experience associated with actual or potential tissue damage, or described in terms of such damage (WHO). It is experienced by everyone regardless of age, gender or economic status. It may be acute or chronic, with unbearable and chronic pain representing extreme problems for the patient. Being a multidimensional and complex phenomenon, it requires an interdisciplinary approach to assessment and intervention. Among the health-care professionals, nurses are the ones who have frequent contact with patients. Hence they assume a major role in identifying the patient who has pain, assessing its impact on the patient and the patients family and initiating action to alleviate pain using available resources (Richardson 2006). To understand pain, it is important to know the various psychological theories of pain. There are many theories which are put forward to understand pain. The most popular theories are the Specificity theory, the Pattern theory and the Gate Control theory. The Specificity Theory This was the primary theory of pain until the middle of the 20th century. According to this theory, the damaged nerve fibers in our bodies send direct messages through the specific pain receptors and fibers to the pain center, the brain which causes the individual to feel pain (Adams and Bromley, 1998). Hence, the intensity of pain is directly related to the amount of associated tissue injury. It was believed that surgery or medication that took care of the tissue injury and its consequences should eliminate the root cause or source of pain. Although this assumption was valid for acute pain, it failed to take care of chronic pain. Patients were subjected to unnecessary procedures which only failed and led to further demoralization of the patient. Also, the fact that effectiveness of hypnosis as a mode of pain relief in the helpless Phantom limb’ pain further undermines this theory. As a result, this theory was discredited and evolvement of other theories occurred. The Pattern Theory According to this theory, pain is felt as a consequence to the amount of tissue damaged and nerve fibers that carry pain signals can also transmit messages of cold, warmth and pressure (Adams and Bromley, 1998). Actually, several different pattern theories were proposed and they considered brain as a passive receiver of messages (Melzack 1993). Both Pattern theory and Specificity theory do not include psychological aspects of pain. These theories could not reason why injured soldiers from war did not experience much pain as compared to others with similar injuries. Thus, gradually, psychological aspect also was included in the process of pain giving rise to the famous ‘Gate Control Theory of Pain’. The Gate Control Theory of Pain The Gate Control theory, also referred to as biopsychosocial model is the first and the only theory to take into account psychological factors of pain experiences. It was proposed by Wall and Melzack in 1965. According to this theory, transmission of nerve impulses from afferent fibers to spinal cord transmission cells is modulated by a spinal gating mechanism in the dorsal horn which is influenced by the relative amount of activity in large-diameter and small-diameter fibers and by nerve impulses that descend from the brain. Activity in large fibers tends to inhibit transmission (close the gate) while activity in small fibers tends to facilitate transmission (open the gate). The substantia gelatinosa in the dorsal horn of the spinal cord was the proposed location of the gate. The rapidly conducting fibers (the Central Control Trigger) of the large diameter fibers activate the selective cognitive processes. These, by way of descending fibers, then modulate properties of the spinal gating mechanism. When the output of the spinal cord transmission cells exceeds a critical level, it activates the Action System. The Action system consists of those neural areas that underlie the complex, sequential patterns of behavior and experience characteristic of pain (Melzack 1993). This theory supports the fact that experiences of pain are influenced by many physical and psychological factors such as beliefs, prior experience, motivation, emotional aspects, anxiety and depression. This theory claims that pain may be experienced without any physical injury and individuals interpret pain differently even though the extent of injury is the same. The pain does not occur at the site of injury, it is experienced in the nervous system, notably the brain. The experience of pain is a function of physical, psychological and environmental factors operating in concert with each other. This is supported by the fact that patients who suffer pain, especially the chronic pain experience psychological distress which can actually increase the subjective experience of pain and impede physical recovery. This understanding of pain has led to a holistic approach of pain management which is found to be more effective in terms of patient recovery and decreased cost of health care (Robert 1997). The need for psycho-social interventions like psychotherapy, relaxation training, support groups, counseling, education, mood management like cognitive behavior therapy and motivation, along with physical treatment of the disease or injury has been stressed upon. This is because; psychological interventions have a direct effect on the neural pathways that control the experience of pain. This theory has further evolved in to the neuromatrix theory of pain. According to this theory, pain is a multidimensional experience produced by characteristic "neurosignature" patterns of nerve impulses that are generated by a widely distributed neural network that can be called the "body-self neuromatrix" and which is located in the brain. There are multiple factors that trigger the neuromatrix to produce ‘neurosignature’. These include sensory inputs (visual, temperature, tactile and other sensory inputs that influence cognitive interpretation), emotional inputs, intrinsic neural inhibitory modulation and the activity of the stress-regulation system (endocrine, autonomic, immune, and opioid systems). This process is nothing but an expansion of the central control processes in the original gate control theory. The central control processes would encompass cognitive-evaluative, motivational-affective, and sensory-discriminative systems. From this understanding, it is clear that pain may be triggered by a variety of sensory inputs, but may also be generated independently of them. Hence pain is a product of the widely distributed neural network in the brain and not directly due to nociceptive stimuli arising from injury (Melzack 2002). Clinical application of psychological theory Since the understanding of the psychological aspects of pain, approach to the management of pain, especially the distressing chronic pain has changed. Patients with chronic neuropathic pain are now managed with both pharmacological and non-pharmacological methods. They are trained in self-management to minimize pain flares and optimize mood and functioning. The cognitive-behavioral model is used to interpret changes in pain in a helpful way and engage in health promoting behaviors (including diet and exercise). The patient is also given psychological help to cope with pain exacerbations. The main purpose of this approach is to help patients become experts in understanding and managing their pain on their own so that their emotions, daily activities, and important relationships are not affected. Self-initiated techniques, such as relaxation, imagery, sexual fantasies and hypnosis, can also be used to alter the subjective experience of pain. Nurses who are in constant touch with the patients have a major role to play in such pain management (Arnstein 2004). Also, psychological consequences to chronic pain like depression, anxiety disorder, somatization disorder, and drug dependence are more and more recognized now and managed appropriately (Manchikanti 2002). References Adams, B. & Bromley, B., 1998. Psychology for Health Care: Key terms and Concepts. USA: Macmillan Press Ltd. Arnstein, P., Dec. 2004. Chronic neuropathic pain: issues in patient education. Pain Manag Nurs., 5(4), pp.34-41 Dannenbaum,S.E., The Evolving Theory of Pain management, Available from: https://www.mhn.com/static/pdfs/Details_Evolving_Theory_Pain_[Cited on 10th July 2007] Manchikanti, L., Fellows, B., and Singh, V., Jan.2002. Understanding psychological aspects of chronic pain in interventional pain management. Pain Physician, 5(1), pp.57-82. Melzack, R., 1993. Pain: Past, Present and Future. Canadian Journal of Experimental Psychology, 47(4), pp. 615-629 Melzack, R., 2001. Pain and the neuromatrix in the brain. J Dent Educ, 65, pp.1378-1382. Melzack, R.,2002. Evolution of pain theories. Program and abstracts of the 21st Annual Scientific Meeting of the American Pain Society: March 14-17, Baltimore, Maryland. Abstract 102. Richardson, C., Adams, N., and Poole, H., Sep.2006.Psychological approaches for the nursing management of chronic pain: part 2. J Clin Nurs.,15(9), pp.1196-202. Robert, K., 1997. The Psychology and Management of Pain Gate Control as Theory and Symbol. Theory & Psychology, 7(1), pp.43-65. Read More