Pain was categorized into being either psychogenic pain or organic pain. Psychogenic
pain was considered to be ‘all in the patient’s mind’ and was a label given to pain
when no organic basis could be found. Organic pain was regarded as being ‘real pain’
and was the label given to pain when some clear injury could be seen.
INCLUDING PSYCHOLOGY IN THEORIES OF PAIN
The early simple models of pain had no role for psychology. However, psychology came
to play an important part in understanding pain through the twentieth century. This
was based on several observations:
First, it was observed that medical treatments for pain (e.g. drugs, surgery) were, in
the main, only useful for treating acute pain (i.e. pain with a short duration). Such
treatments were fairly ineffective for treating chronic pain (i.e. pain which lasts for a long
time). This suggested that there must be something else involved in the pain sensation
which was not included in the simple stimulus response models.
It was also observed that individuals with the same degree of tissue damage
differed in their reports of the painful sensation and/or painful responses. Beecher
(1956) observed soldiers’ and civilians’ requests for pain relief in a hospital during the
Second World War. He reported that although soldiers and civilians often showed
the same degree of injury, 80 per cent of the civilians requested medication, whereas
only 25 per cent of the soldiers did. He suggested that this reflected a role for the
meaning of the injury in the experience of pain; for the soldiers, the injury had a positive
meaning as it indicated that their war was over. This meaning mediated the pain
experience.
The third observation was phantom limb pain. The majority of amputees tend to feel
pain in an absent limb. This pain can actually get worse after the amputation, and
continues even after complete healing. Sometimes the pain can feel as if it is spreading
and is often described as a hand being clenched with the nails digging into the palm
(when the hand is missing) or the bottom of the foot being forced into the ankle (when
the foot is missing). Phantom limb pain has no peripheral physical basis because the limb
is obviously missing. In addition, not everybody feels phantom limb pain and those who
do, do not experience it to the same extent. Further, even individuals who are born with
missing limbs sometimes report phantom limb pain.
These observations, therefore, suggest variation between individuals. Perhaps this
variation indicates a role for psychology.
THE GATE CONTROL THEORY OF PAIN
Melzack and Wall (1965, 1982; Melzack 1979), developed the gate control theory
of pain (GCT), which represented an attempt to introduce psychology into the under-
standing of pain. This model is illustrated in Figure 12.1. It suggested that although pain
could still be understood in terms of a stimulus–response pathway, this pathway
was complex and mediated by a network of interacting processes. Therefore, the GCT
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