bee & poppy

Chronic pain as psychiatric disorder


For years I’ve taken a stance that chronic pain is not a psychiatric disorder. Yes, it’s associated with depression, anxiety and a host of other problems, but in itself it’s not primarily a mental health problem. I was taken to task for this the other day. The argument went like this:

“Pain disorder”: chronic pain…thought to be caused by psychological stress.  I argued that I didn’t like the label, and have met more people with psychological problems after they’ve developed chronic pain, rather than chronic pain initiated through psychological stress. The International Association for the Study of Pain notes accompanying the definition of pain states:

“Many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons…. pain most often has a proximate physical cause (http://www.iasp-pain.org/Taxonomy?navItemNumber=576).”

Some people argue that this set of statements doesn’t consider central sensitisation (it was written before there were ways to examine living brain function) – but the end result was, as intended, to equate the experience of pain with only the experience of pain, rather than nociception or tissue damage. The person who disagreed with me suggested I was denigrating those with a mental health diagnosis – I hope I’m not, because illness affects people whether it’s so-called “physical” or “mental”.

Studies have shown that some people do develop chronic pain after being exposed to workplace stress – but haven’t been able to demonstrate that this is a direct stress —> pain relationship. Instead there could be any number of mediating and moderating factors, such as genetic predisposition to chronic pain, tendency to respond to stress with fatigue and increased risk of making errors, response from within the workplace system, working faster and harder because of stress, limited attention to recovery and so on. To show a direct relationship between stress and developing chronic pain, we’d need to see clear evidence of an impact on biological systems that are involved with both stress and pain, and we’d need to see a dose-response relationship and so on. There’s some suggestion that chronic stress may influence the HPA axis, particularly during childhood development, but the main hypothesis about stress and cortisol and neuroinflammation (the glucocorticoid cascade hypothesis) doesn’t appear to have translated well from animal studies to humans (Frodl & O’Keane, 2013).  Quintner and colleagues have suggested fibromyalgia may be the outcome of long-term adaptation to stress, but this hypothesis has not yet been rigorously tested (Lyon, Cohen & Quintner, 2011).

My stance on stress and chronic pain is that having chronic pain is extremely stressful. When a person experiences pain it disrupts and interferes with usual bodily experience during movement and rest. Being unable to do what’s important in life is frustrating, and can lead to social rejection – social rejection itself activates a number of neural pathways that are very similar to those active in chronic pain (MacDonald & Leary, 2005). There’s no doubt that for some people, the demoralising effect of trying time after time for a diagnosis, and the search for effective treatment is stressful enough to produce depression and/or anxiety, and certainly a sense of hopelessness and helplessness. If you happen to be vulnerable to mood problems, or to the effects of stress on a sensitive nervous system, then I’m certain there is a relationship between the two. But not in every case, and not all the time. And the jury is still out on which came first: the mood problem or the chronic pain.

Whatever, I have other reasons for not wanting chronic pain to be labelled a psychiatric disorder. Like it or not, mental health problems are not as well accepted socially as say, breaking a leg or having the flu. Despite the vigorous efforts of many people to raise awareness about depression and anxiety, it’s not anywhere near as easy to announce to people “I’ve got depression” than it is to say “I’ve got the flu”. It’s more difficult if you have chronic pain. Not only is there a really strong belief in the general community that pain should be associated with some sort of visible tissue insult, this belief carries through to many health professionals. Hopefully that’s changing, but far too slowly. What’s worse, many insurers and much compensation law identifies that if there’s no tissue damage, or the problem can’t be imaged, then pain is not a compensable condition. This places the person experiencing pain in an incredibly difficult position – how to demonstrate to people around them that they have a problem that isn’t imaginary and can’t be shrugged off.

Now add another layer of complexity to the argument. By labeling chronic pain a psychiatric disorder, the person being thus labelled experiences a double-whammy. Their pain may be real but not acknowledged, their suffering may be acknowledged but labelled a psychiatric problem. And very often treatment for psychiatric conditions is poorly funded, with limited attention to a biopsychosocial model or to an interdisciplinary approach.

A person given a diagnosis of “somatic symptom and related disorder” (according to DSM 5) is meant to mean they have “somatic symptoms associated with significant distress and impairment.”  The diagnosis is to be made “on the basis of positive symptoms and signs (distressing somatic symptoms plus abnormal thoughts, feelings, and behaviors in response to these symptoms) rather than the absence of a medical explanation for somatic complaints.” (See DSM-5, p. 309.)

I wonder, what are “abnormal” thoughts, feelings and behaviours in response to pain?  How is this judged? Who does the judging? What’s normal? Simply having pain that no-one can explain is, in itself, distressing. I’d have thought this was a pretty normal response.

The American Psychiatric Association states that the DSM 5 Pain Disorder diagnosis “takes a different approach to the important clinical realm of individuals with pain”. They go on to say “In DSM-IV, the pain disorder diagnoses assume that some pains are associated solely with psychological factors, some with medical diseases or injuries, and some with both. There is a lack of evidence that such distinctions can be made with reliability and validity, and a large body of research has demonstrated that psychological factors influence all forms of pain. Most individuals with chronic pain attribute their pain to a combination of factors, including somatic, psychological, and environmental influences. In DSM-5, some individuals with chronic pain would be appropriately diagnosed as having somatic symptom disorder, with predominant pain. For others, psychological factors affecting other medical conditions or an adjustment disorder would be more appropriate.”(click here for the document)

By acknowledging that it’s not possible to distinguish between pain associated with psychological, medical, injury or both, I think this category is a catch-all. I think it’s acknowledging that chronic pain is a problem that many people with mental health problems experience, and it recognises that clinicians working with those who have mental health problems need a box to tick to enable them to address the issues and be paid for it. This isn’t attacking those clinicians who use DSM V to justify their involvement with people who experience chronic pain. But I think it’s a clumsy way of addressing the underlying issue that means insurers and legislators STILL believe there has to be tissue damage, or something we can “see” before a person can have real pain.

 

Frodl, Thomas, & O’Keane, Veronica. (2013). How does the brain deal with cumulative stress? A review with focus on developmental stress, HPA axis function and hippocampal structure in humans. Neurobiology of Disease, 52(0), 24-37. doi: http://dx.doi.org/10.1016/j.nbd.2012.03.012

Lyon, Pamela, Cohen, Milton, & Quintner, John. (2011). An evolutionary stress-response hypothesis for chronic widespread pain (fibromyalgia syndrome). Pain Medicine, 12(8), 1167-1178.

MacDonald, Geoff, & Leary, Mark R. (2005). Why does social exclusion hurt? The relationship between social and physical pain. Psychological bulletin, 131(2), 202.

6 comments

  1. Griffith Uni’s Prof Diego De Leo has lectured on fibro at conferences on suicide. Roughly half of such deaths hadn’t any psych history (https://www.researchgate.net/publication/224951475_Suicide_in_the_absence_of_mental_disorder_A_review_of_psychological_autopsy_studies_across_countries) but Calandre’s survey of 180 Spanish fibromites found 1 in 6 had attempted it unsucccessfully. Add to that Jason’s scrutiny of death certificates on a CFS register showing another 1 in 6 were fatal. The determination that pain and mental disorder are linked is costing focus on rational persons unable to cope with pain, and thereby costing lives.

    1. I wonder if there are any studies showing the risk associated with suicide if depression is controlled for. What I mean by this is, if a person doesn’t have depression but does have chronic pain, are they more at risk of suicidal behaviour? It’s definitely something I always screen for, and most people are relieved I talk about it. Thinking about it doesn’t mean acting on it, and just knowing that can help people feel less concerned.

      1. There’s a major deficiency in data-gathering. The WHO recommended death cert only solicits conditions directly leading to, or contributing to the death. There’s no request for medication regime – not even a consideration of iatrogenic harm, eg discharge from hospital the day prior is considered irrelevant. However police, psychiatrists (but only if involuntary Pt) and anaesthetists are treated with suspicion, their recent involvement must be reported to the coroner.

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