|Home | About | Journals | Submit | Contact Us | Français|
There is a strong tradition of therapy development and evaluation in the field of psychological interventions for chronic pain. However, despite this research production, the effects of treatments remain uncertain, and treatment development has stalled. This review summarises the current evidence but focusses on promising areas for improvement. Advancing psychological therapies for chronic pain will come from a radical re-imagining of the content, delivery, place, and control of therapy. The next generation of therapeutic interventions will also need alternative methods of measurement and evaluation, and options are discussed.
Psychological treatments—in particular, cognitive behaviour therapies—have been a mainstay of chronic pain management. The population of people who seek treatment for chronic pain is growing, and there is a rising incidence of chronic neuropathic pain 1, the growing realisation of the burden of pain in later life 2, and a recognition that performance of pharmacological interventions is disappointing 3. Despite the demand for treatment, progress in psychological therapy has now reached a turning point, and there is no clear direction on the route to take. This is a timely juncture to look critically at the evidence we have, to understand why treatment development is failing, and to consider how to cut a new path to clinical progress.
The evidence for the efficacy of psychological interventions is largely underwhelming. There are four main Cochrane systematic reviews of psychological interventions for improving pain, affect, and disability in chronic pain—two with adults 4, 5 and two with adolescents 4, 6. This is not an under-researched area. Altogether, 101 randomised controlled trials (RCTs) have been conducted. For adults, behavioural and cognitive behavioural treatments show moderate-effect sizes of benefit over waiting lists and small or no effects over active comparators for outcomes in pain, disability, and mood. However, uncertainty over the effect estimates remains high because of poor-quality and small studies. For treatments of children and adolescents, there is moderate-quality evidence of efficacy of cognitive behavioural therapy (CBT), in particular for headache, and evidence is developing for musculoskeletal pain conditions such as fibromyalgia 7. The quality of recent trials in paediatrics is high, and there is innovation in methods of remote delivery 8. In paediatric pain, however, there is an historical absence of evidence for non-pain outcomes such as psychological and physical functioning, and for non-patient stakeholders such as parents or siblings. From 101 RCTs, the best conclusion we can draw is that there is low-quality evidence of small to moderate effects of CBT for chronic pain, meaning that the effect estimates could easily change with new evidence.
Perhaps the next 101 trials will help us. Without change, however, we believe not. In 2013, we argued that there should be a halt on trial registration, until the quality and focus radically improve, because of a significant threat of research waste 9. There should be no new trials until three critical problems are addressed. First, treatment should be based on an extant model of behaviour change. In psychology, it is normal practice to run phase II or III studies without pre-clinical work or phase I study. Post hoc theorising is common. There should be a scientifically plausible reason for behaviour change, stated and mapped, and one should always assume the possibility of harm. Second, clinical endpoints of treatments and thresholds of treatment success should be established by the community. At present, the field is awash with therapist- or researcher-driven measurement. Outcomes developed and determined by patients, with meaningful endpoints, will help enormously. Dichotomous outcomes of meaningful changes in health state are rarely reported, relying instead on the use of continuous variables aggregated across groups. Third, innovation will come only by creating pathways from pre-clinical to clinical studies, by better understanding patient need, by resisting the errant individualisation of social problems which position responsibility for change with the individual alone, and by challenging the habit of pathologising normal, albeit maladaptive, behaviour. A new paradigm for developing innovative treatment is needed, requiring both theoretical and methodological attention.
There is promising work in four areas: in the search for common transdisciplinary mechanisms of therapeutic change, in better profiling of patient need and consequent tailoring of content, in exploring embodied pain models for analgesic as well as rehabilitative intervention, and in the use of computing technology to re-imagine therapeutic practice.
Next-generation therapies for chronic pain, indeed for psychological therapy in general, demand a new generation of methods. How we establish ‘what works for whom’ remains the critical challenge in pain science. Three areas deserve attention. First, there is a significant measurement problem in construct definition, independence, and relevance. Second, there is a unit-of-analysis problem. Individual experience is rarely investigated or reported, but the novel therapies discussed here will need sophisticated within-subject investigations. Finally, the quality of both conduct and reporting of studies needs to be considered and then improved.
There has been tremendous industry in producing a large number of RCTs, and even more uncontrolled evaluations, of psychological interventions for outcomes in chronic pain. But uncertainty over efficacy and harm remains. A radical re-imagining of therapy for chronic pain is needed, not least by a consideration of the role of technology improving access to existing therapy, and the therapy itself. Directly altering pain through a consideration of embodied perception—an embodied pain approach—offers exciting avenues for exploration 18. Making use of traces of data we leave from pervasive sensing and communication technology is especially promising. Methods of assessment and evaluation will also need to be developed, in particular to match therapy delivery that is tailored to individual needs or problems in ecological or natural environments. Guiding principles for advancing psychological therapies for chronic pain will be to ensure better translation from pre-clinical studies of pain and to protect equipoise from the threat of bias.
[version 1; referees: 2 approved]
The author(s) declared that no grants were involved in supporting this work.
F1000 Faculty Reviews are commissioned from members of the prestigious F1000 Faculty and are edited as a service to readers. In order to make these reviews as comprehensive and accessible as possible, the referees provide input before publication and only the final, revised version is published. The referees who approved the final version are listed with their names and affiliations but without their reports on earlier versions (any comments will already have been addressed in the published version).
The referees who approved this article are: