Abstract
BACKGROUND
Medically unexplained physical symptoms (MUPS) are physical symptoms for which no adequate medical explanation can be found after proper examination. The presence of MUPS is the key feature of conditions known as 'somatoform disorders'. Various psychological and physical therapies have been developed to treat somatoform disorders and MUPS. Although there are several reviews on non-pharmacological interventions for somatoform disorders and MUPS, a complete overview of the whole spectrum is missing.
OBJECTIVES
To assess the effects of non-pharmacological interventions for somatoform disorders (specifically somatisation disorder, undifferentiated somatoform disorder, somatoform disorders unspecified, somatoform autonomic dysfunction, pain disorder, and alternative somatoform diagnoses proposed in the literature) and MUPS in adults, in comparison with treatment as usual, waiting list controls, attention placebo, psychological placebo, enhanced or structured care, and other psychological or physical therapies.
SEARCH METHODS
We searched the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Register (CCDANCTR) to November 2013. This register includes relevant randomised controlled trials (RCTs) from The Cochrane Library, EMBASE, MEDLINE, and PsycINFO. We ran an additional search on the Cochrane Central Register of Controlled Trials and a cited reference search on the Web of Science. We also searched grey literature, conference proceedings, international trial registers, and relevant systematic reviews.
SELECTION CRITERIA
We included RCTs and cluster randomised controlled trials which involved adults primarily diagnosed with a somatoform disorder or an alternative diagnostic concept of MUPS, who were assigned to a non-pharmacological intervention compared with usual care, waiting list controls, attention or psychological placebo, enhanced care, or another psychological or physical therapy intervention, alone or in combination.
DATA COLLECTION AND ANALYSIS
Four review authors, working in pairs, conducted data extraction and assessment of risk of bias. We resolved disagreements through discussion or consultation with another review author. We pooled data from studies addressing the same comparison using standardised mean differences (SMD) or risk ratios (RR) and a random-effects model. Primary outcomes were severity of somatic symptoms and acceptability of treatment.
MAIN RESULTS
We included 21 studies with 2658 randomised participants. All studies assessed the effectiveness of some form of psychological therapy. We found no studies that included physical therapy.Fourteen studies evaluated forms of cognitive behavioural therapy (CBT); the remainder evaluated behaviour therapies, third-wave CBT (mindfulness), psychodynamic therapies, and integrative therapy. Fifteen included studies compared the studied psychological therapy with usual care or a waiting list. Five studies compared the intervention to enhanced or structured care. Only one study compared cognitive behavioural therapy with behaviour therapy.Across the 21 studies, the mean number of sessions ranged from one to 13, over a period of one day to nine months. Duration of follow-up varied between two weeks and 24 months. Participants were recruited from various healthcare settings and the open population. Duration of symptoms, reported by nine studies, was at least several years, suggesting most participants had chronic symptoms at baseline.Due to the nature of the intervention, lack of blinding of participants, therapists, and outcome assessors resulted in a high risk of bias on these items for most studies. Eleven studies (52% of studies) reported a loss to follow-up of more than 20%. For other items, most studies were at low risk of bias. Adverse events were seldom reported.For all studies comparing some form of psychological therapy with usual care or a waiting list that could be included in the meta-analysis, the psychological therapy resulted in less severe symptoms at end of treatment (SMD -0.34; 95% confidence interval (CI) -0.53 to -0.16; 10 studies, 1081 analysed participants). This effect was considered small to medium; heterogeneity was moderate and overall quality of the evidence was low. Compared with usual care, psychological therapies resulted in a 7% higher proportion of drop-outs during treatment (RR acceptability 0.93; 95% CI 0.88 to 0.99; 14 studies, 1644 participants; moderate-quality evidence). Removing one outlier study reduced the difference to 5%. Results for the subgroup of studies comparing CBT with usual care were similar to those in the whole group.Five studies (624 analysed participants) assessed symptom severity comparing some psychological therapy with enhanced care, and found no clear evidence of a difference at end of treatment (pooled SMD -0.19; 95% CI -0.43 to 0.04; considerable heterogeneity; low-quality evidence). Five studies (679 participants) showed that psychological therapies were somewhat less acceptable in terms of drop-outs than enhanced care (RR 0.93; 95% CI 0.87 to 1.00; moderate-quality evidence).
AUTHORS' CONCLUSIONS
When all psychological therapies included this review were combined they were superior to usual care or waiting list in terms of reduction of symptom severity, but effect sizes were small. As a single treatment, only CBT has been adequately studied to allow tentative conclusions for practice to be drawn. Compared with usual care or waiting list conditions, CBT reduced somatic symptoms, with a small effect and substantial differences in effects between CBT studies. The effects were durable within and after one year of follow-up. Compared with enhanced or structured care, psychological therapies generally were not more effective for most of the outcomes. Compared with enhanced care, CBT was not more effective. The overall quality of evidence contributing to this review was rated low to moderate.The intervention groups reported no major harms. However, as most studies did not describe adverse events as an explicit outcome measure, this result has to be interpreted with caution.An important issue was that all studies in this review included participants who were willing to receive psychological treatment. In daily practice, there is also a substantial proportion of participants not willing to accept psychological treatments for somatoform disorders or MUPS. It is unclear how large this group is and how this influences the relevance of CBT in clinical practice.The number of studies investigating various treatment modalities (other than CBT) needs to be increased; this is especially relevant for studies concerning physical therapies. Future studies should include participants from a variety of age groups; they should also make efforts to blind outcome assessors and to conduct follow-up assessments until at least one year after the end of treatment.
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