Pain – A Biopsychosocial Approach
Pain is a complex process, rather than just a simple connection between nerves. Instead there is an interface between physical and psychology processes. Pain involves nerve stimulation, signals are sent to the brain where they are then processed and a ‘response’ sent back. During this process the pain signal can be modulated. Melzack & Wall (1965) developed ‘gate control theory’, as a way to explain how nerve signals were modulated. They suggested that when nerve signals arrive at the spinal area, specifically the ‘dorsal horn’, the balance of this activity could stimulate or inhibit the transmission to the next nerve. Thus, at this point a ‘gate’ is formed, with some nerve impulses being allowed through (gate opened) and others inhibited (gate closed).
The closing of a gate is regulated in the spinal cord by activity of nerve impulses. The brain can also send nerve signals to close the gate, blocking transmission. For example, in very stressful situations e.g. war or accidents, people who have severe injuries may not at the time of the injury experience pain; as their attention is focussed on survival; thus the gate is closed and pain is not experienced. Additional influences are certain chemicals e.g. endorphins, which have an anajelsic effect. The release of these can be raised by exercise, but lowered by stress. Factors such as focusing on pain, stress/tension, anxiety and depression are thought to open the gate and intensify the experience of pain. Thus, pain experience is modulated by sensory feedback and higher central nervous system influences.
Magnetic resonance imaging and PET scans, show that many parts of the brain are active during pain perception. Here pain emotions and behaviour are closely integrated, suggesting that the processing of emotions, behaviour and pain are closely linked. The processing taking place in the brain demonstrates the connectedness of perceptual, emotional, cognitive and behavioural aspects.
Behaviour influences the processing of pain perception, and may also have an impact on physiological changes. If an individual expects pain, it has been seen that this results in stimulation of the same areas of the brain as actual painful stimulus: ‘prediction’ of pain can contribute to the experience of pain.
Thus the experience of pain is both biological and psychological, and has psychosocial repercussions. A biopsychosocial approach to understanding and coping with pain takes into account the biological, psychological and social factors that affect the experience of and coping with pain, allowing for and encompassing a wider variety of treatment options.