Psychological therapies for the management of chronic neuropathic pain in adults
Neuropathic pain is thought to arise from damage to the somatosensory nervous system. Its prevalence is increasing in line with many chronic disorders such as diabetes. All treatments have limited effectiveness. Given the evidence regarding psychological treatment for distress and disability in people with various chronic pain conditions, we were interested to investigate whether psychological treatments have any effects for those with chronic neuropathic pain.
To assess the effects of psychological treatments on pain experience, disability, mood, and health‐care use in adults with chronic neuropathic pain.
We searched for randomised controlled trials (RCTs) published in any language in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and PsycINFO, from database inception to March 2015.
Full publications of RCTs on psychological interventions for neuropathic pain. Trials had to have lasted at least three months, had at least 20 participants in each arm at the end of treatment, and compared a psychological intervention with any active or inactive intervention.
Data collection and analysis
We used the standard methodological procedures expected by Cochrane.
Two small studies (enrolling a total of 105 participants) met the inclusion criteria. One was a standard cognitive behavioural treatment (CBT) programme for 61 people with pain from spinal cord injury, followed up for three months, and compared with a waiting list. The other was weekly group psychotherapy for 44 people with burning mouth syndrome, compared with a daily placebo tablet. The overall risk of bias was high in both trials.
The CBT study assessed participants for pain, disability, mood, and quality of life, with improvement in treatment and control groups. However, there was no more improvement in the treatment group than in the control for any outcome, either post‐treatment or at follow‐up. The group psychotherapy study only assessed pain, classifying participants by pain severity. There is a lack of evidence on the efficacy and safety of psychological interventions for people with neuropathic pain.
There is insufficient evidence of the efficacy and safety of psychological interventions for chronic neuropathic pain. The two available studies show no benefit of treatment over either waiting list or placebo control groups.
Christopher Eccleston, Leslie Hearn, Amanda C de C Williams
Plain language summary
Psychological treatments for chronic pain involving damage or disease to nerves responsible for pain
Many people experience pain from an injury or disease that goes away within three months, but for some people the pain continues. When the pain involves changes to nerves we call the pain 'neuropathic'. Although the condition is increasingly common, the treatments we have help only a few people. Following unsuccessful surgical or pharmacological treatment, people with chronic pain may be offered psychologically‐based rehabilitation to improve their quality of life. While we know that this can help people with other types of chronic pain, this treatment for neuropathic pain alone has received less research attention.
In this review, we were interested in finding out whether psychological treatments improve pain, distress, and disability in people with chronic neuropathic pain. We searched the academic literature to March 2015 and identified two randomised controlled trials (the gold standard design for clinical trials) on psychological interventions for chronic neuropathic pain. The two studies included 105 participants: one trial of 61 people with pain from spinal cord injury and the other of 44 people with burning mouth syndrome.
Our confidence in the results of the individual trials was limited by several potential biases in how they were conducted. We were not able to analyse the results of the two trials together because the experiences of people with spinal cord injury or burning mouth are too different from each other. On their own, the trials were too small for us to undertake any statistical analysis. However, neither trial found any clear benefit of treatment. We conclude that there is currently no evidence that will help practitioners and patients to decide whether to use these treatments. We discuss what studies are needed.
Christopher Eccleston, Leslie Hearn, Amanda C de C Williams
Implications for practice
The data recovered in this search and analysis do not provide any meaningful implications for individual practice or policy. Rather, our review demonstrates clearly the lack of direct evidence for or against the effectiveness of psychological interventions in altering the experience of pain, disability and impaired mood associated with chronic neuropathic pain. Thus, for now, there is still a large and growing population of people disabled by chronic neuropathic pain from diabetic neuropathy, cancer treatments, and other causes, who have limited options for treatment.
Implications for research
There is a worrying lack of trial data in this area of need. We need RCTs of specific psychological treatments tailored for neuropathic pain populations. Good candidate conditions for effective trial design and delivery are
- Peripheral Diabetic Neuropathy. An optimal treatment could be cognitive and behavioural methods aiming to increase activity and participation in society, with specific content to address mood disorder, sleep problems, and increased pain on activity. This treatment could be one component in the management of complications from diabetes.
- HIV neuropathy, treated with cognitive and behavioural methods focused on social emotional functioning, compared with no treatment, aiming to address beliefs about pain, low mood, and participation in society, including work. This may be a difficult group to engage and the delivery of rehabilitative treatment might be more effective outside direct health service settings (Davis 2004).
- Postherpetic neuralgia, treated with cognitive behavioural therapy incorporating some of the exposure methods used with CRPS, compared with nonspecific support and medication. Outcomes of interest might include better management of provoked pain, more engagement in valued activities, and less anxiety and depression concerning the pain (Daniel 2008).
All trials would need to be sufficiently powered (200 patients or more) and involve service users in their design, which would include acceptable comparison groups and options for supplementary content using electronic media. Placebo comparison groups should control for patient trust and belief in therapy outcome (i.e. be equally credible), time of exposure to therapy, and general educational content. Primary endpoints should follow other neuropathic pain treatments in terms of pain, but investigators should define potential improvements in distress, disability, quality of life, pain, sleep, and acceptability/adherence in advance, also routinely reporting adverse events. See Morley 2013 for further discussion.
More generally, and to facilitate future reviews, it would be helpful if abstracts contained essential information about what treatment is used, for which pain problem, in how many participants, and what outcomes are reported, as well as whether the study was randomised and what the comparison conditions were. Reviewers can assess the studies that include this information in the abstract more effectively than those that do not.