From time to time I see a flurry of tweets or Facebook posts about pain and psychosocial factors. Many of them are informative, intriguing and empathic, but some are just plain wrong. The ones I most get upset about are those arguing that because someone has “psychosocial factors” their pain must be psychological in origin, followed closely by the idea that psychosocial factors equate to psychopathology. This is a series of back to basics posts where I hope to set these things right.
Pain, according to the current definition, is
“an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” is derived from a 1964 definition by Harold Merskey, and it was first published in 1979 by IASP in PAIN, number 6, page 250.
An associated note, which should be read alongside this definition is:
Note: The inability to communicate verbally does not negate the possibility that an individual is experiencing pain and is in need of appropriate pain-relieving treatment. Pain is always subjective. Each individual learns the application of the word through experiences related to injury in early life. Biologists recognize that those stimuli which cause pain are liable to damage tissue. Accordingly, pain is that experience we associate with actual or potential tissue damage. It is unquestionably a sensation in a part or parts of the body, but it is also always unpleasant and therefore also an emotional experience. Experiences which resemble pain but are not unpleasant, e.g., pricking, should not be called pain. Unpleasant abnormal experiences (dysesthesias) may also be pain but are not necessarily so because, subjectively, they may not have the usual sensory qualities of pain. Many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons. There is usually no way to distinguish their experience from that due to tissue damage if we take the subjective report. If they regard their experience as pain, and if they report it in the same ways as pain caused by tissue damage, it should be accepted as pain. This definition avoids tying pain to the stimulus. Activity induced in the nociceptor and nociceptive pathways by a noxious stimulus is not pain, which is always a psychological state, even though we may well appreciate that pain most often has a proximate physical cause.
The final sentence in the note is important, distinguishing between the experience of pain and the biological apparatus transmitting information from the nociceptors, ending in a bunch of places in the brain. I personally dispute the sentence “many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons” because (recall when it was first written) science has moved on and we now have good evidence supporting the notion that abnormal processing is involved in cases such as migraine (Iyengar, Ossipov & Johnson, 2017; Pietrobon, 2017) and fibromyalgia (Schmidt-Wilcke & Diers, 2017; Tour, Lofgren, Mannerkorpi, Gerdle, Larsson, Palstam et al, 2017). As a side note, I love science because we can revisit beliefs and revise our understanding as more information is collected – whether we’ll ever get to the “truth” is debatable, but we can get closer and closer as we continue learning (see Bhaskar).
Back to basics. It’s evident that ALL pain is a psychological experience and therefore will be influenced by our current goals, past experiences and predictions for the future. And these aspects of attention, motivation, memory and decision-making are present in all of us and for every sensory experience. Take sound, for example. I’m sitting at home listening to a large truck rumbling away, dumping construction materials in the section two doors down. That sound is so like the deep rumble and thud of an earthquake that I’m aware I’m on edge because, after more than 10,000 earthquakes since the first one in the Canterbury region this day seven years ago, my nervous system has learned to be on high alert – who knows what could happen next?
Seven years of learning, 10,000 earthquakes-worth of learning, lots of emotions and lots of very real and scary outcomes. It affects people. In the same way, pain, which we learn about from birth, is influenced by personal experience, by other people’s experiences, and by prevailing community attitudes. This is not psychopathology – at least, not for me though some people have experienced PTSD as a result of the earthquakes we’ve been through. You’d likely do that if you were trapped in a building with no way out, and countless aftershocks continuing while rescuers try to get to you. Most people in Christchurch, however, have simply learned to be aware of sights and sounds that signal a quake – and quickly get back to usual once the sounds have gone. Similarly, most people who experience pain, don’t have a mental health problem – they’ve learned, as we all do, that pain is unpleasant, and learn to avoid situations where pain is likely to occur. In our society, experiencing pain is not viewed as “normal” and indeed, some people have called us “algophobic” – afraid of pain (Kugelmann, 2016). This means we’ve learned to look for ways to get rid of our pain, even if it’s not very intense – because pain means something is “not right” with us.
And one of the functions of pain is to alert us to the potential that something is threatening our bodily integrity, and withdraw or avoid such situations (ie, to learn from them). And as a species we’re designed to be social, so we also display behaviour when we’re hurt that others can see – thus helping spread the word “don’t do that dumb thing!” (Steinkopf, 2016).
To summarise: pain is an experience we’ve all had, and yet it remains something we don’t fully understand. Irrespective of the modality of sensory experience, humans are hard-wired to make sense of, and act upon, experiences based on prior learning, current goals and future predictions, within a context that is inherently social. We’re actively engaged in making sense of our experiences so we can remain safe and give and receive support from those around us. While the experience is psychological, the apparatus producing that experience is biological, filtered through our social and contextual experiences. Like taste, sound, and colour – pain is inherently subjective.
Next post – does this mean the biological is redundant?