Short-Term Psychodynamic Psychotherapy for Somatic Disorders: Systematic Review and Meta-Analysis of Clinical Trials

Background: Somatic symptom disorders are common, disabling, and costly. Individually provided short-term psychodynamic psychotherapies (STPP) have shown promising results. However, the effectiveness of STPP for somatic symptom disorders has not been reviewed. Methods: We undertook a systematic review of randomized controlled trials (RCTs) and controlled before and after studies. Outcomes included psychological symptoms, physical symptoms, social-occupational function, healthcare utilization and treatment continuation. Results: A total of 23 studies met inclusion criteria and cover a broad range of somatic disorders. Thirteen were RCTs and 10 were case series with pre-post outcome assessment. Of included studies, 21/23 (91.3%), 11/12 (91.6%), 16/19 (76.2%) and 7/9 (77.8%) reported significant or possible effects on physical symptoms, psychological symptoms, social-occupational function and healthcare utilization respectively. Meta-analysis was possible for 14 studies and revealed significant effects on physical symptoms, psychiatric symptoms and social adjustment which were maintained in long term follow-up. Random effects modeling attenuated some of these relationships. There was 54% greater treatment retention in the STPP group versus controls. Conclusion: STPP may be effective for a range of medical and physical conditions underscoring the role of patient’s emotional adjustment in overall health. Future research should include high quality randomized and clinical effectiveness studies with attention to healthcare use and costs. Half of all outpatient medical visits are related to somatic complaints, of which at least one-third to one-half are medically unexplained. [1] Many are individual physical symptoms, such as pain (e.g., low back, joint, chest, abdominal, headache) and nonpain (e.g, fatigue, dizziness, palpitations) complaints. Others consist of a cluster of somatic symptoms for which the etiology is poorly understood such as irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, temporomandibular disorder and interstitial cystitis. These functional somatic syndromes often overlap and are similar in terms of psychiatric comorbidity, functional impairment, and family history. [2,3,4] Distressing somatic symptoms are also increased twoto three-fold in patients with depressive and anxiety disorders. [5,6] More recently, it has also been shown that diseasespecific somatic symptoms in patients with a variety of medical disorders are influenced as much by psychological factors as by the severity of the underlying medical disorder. [7,8] While some patients with medically unexplained symptoms meet criteria for somatoform disorders, the boundaries are not always clearcut between somatoform symptoms and the distressing and persistent somatic symptoms experienced by patients with functional somatic disorders, depression, anxiety, and even some medical conditions. [8] Treatment of somatoform disorders and related conditions manifested by poorly explained somatic symptoms has been covered in several recent comprehensive reviews. [9, 10, 11, 12, 13, 14, 15] Cumulatively, these reviews confirm that two of the most evidence-based treatments are cognitive-behavioral therapy (CBT) and antidepressants. Too few studies of other treatments were then found to lend themselves to a meta-analysis. Unresolved unconscious emotional issues have long been considered an important causal factor in a range of physical illnesses and somatic symptom disorders. [16] In clinical practice, psychodynamic psychotherapies focus on this unconscious process by which emotions translate into somatic symptoms, somatic focus, and, indeed, objectively measurable physical sequelae. Short-term Psychodynamic Psychotherapies (STPP) are a group of brief therapy methods developed over the past 50 years by proponents including Mann, Sifneos, Malan and Davanloo. [17] Some STPP methods aim for insight into various unconscious phenomena while others seek to address alexithymia, or difficulty identifying and experiencing emotions. With these different goals, technical differences have developed over time with some methods being more versus less focused on emotional experiencing. They share the common goals of making unconscious phenomena conscious and working through underlying conflicts. The efficacy of STPP across a range of common mental disorders was reviewed in two recent meta-analyses. [18,19] There are limitations to the generalisability of these findings to the treatment of somatic disorders. One review only included a single study with somatoform disorders [18], and the other excluded studies with formal psychotherapy treatment controls. Both reviews were restricted to RCTs of individual STPP methods. Thus, the great majority of all STPP studies for somatic symptom disorders have never been reviewed. The purpose of this paper is to critically review and meta-analyze where appropriate, data from studies using both RCT and non-RCT designs in order to examine the effectiveness of STPP in patients with somatic symptom disorders. METHODS Selection of studies We included studies of STPP therapies in somatic symptom disorders covering both medically explained and unexplained symptoms without regard to the presence of a formal psychiatric disorder to better reflect the case mix seen in general medical settings. We included both randomized controlled trials as well as before and after studies such as mirror designs of the same subjects. Studies of STPP delivered in either individual or group format were included. Search strategy We searched PsycInfo, 1967-present, Medline 1966-present, and Cochrane Library 2005present up to July 2007. Many papers had been found in a previous broad search conducted for a Cochrane review of STPP therapies for mental disorders. [19] Our strategy included broad searches with the following terms: psychotherapy, psychodynamic, dynamic or short-term therapy and clinical trial, naturalistic study, or randomized trial and 37 specific terms, such as chest pain, abdominal pain and headache. We searched for further trials by scrutinizing the reference lists of initial studies identified and other relevant review papers. We also contacted selected authors and experts. Two reviewers (AA and SK) independently extracted data. Two reviewers collated and independently assessed abstracts. Study Description Studies were reviewed for treatment characteristics, study methodology, sample characteristics, outcome measures, and reported results on primary indices under the categories psychological symptoms, somatic symptoms, social-occupational functioning and healthcare utilization. We specifically noted which studies were manualized, which had adherence ratings and which had blinded ratings of outcome. For randomized controlled trials, we used the Cochrane Collaboration Depression Anxiety and Neurosis (CCDAN) quality rating scale to numerically rate study quality. This 23 item scale includes a broad range of indicators such as allocation concealment and sample size and has a maximum value of 46. Meta-analysis Where appropriate, we combined results of studies using meta-analysis. We used Review Manager version 4.1, a statistical software package for managing and analysing a Cochrane Collaboration systematic review, for our analysis. We divided outcomes into short-term (up to 3 months), medium term (39 months) and long-term (over 9 months), and measured effect size (ES) using standardised mean differences. We defined effect sizes as small (ES 0.20-0.49), medium (ES 0.5-0.79) and large (ES ≥ 0.8). [20] We assessed significance using 95% confidence intervals, and heterogeneity by using the Q and I statistic. A value of greater than 50% for the I statistic indicates heterogeneity. We assessed for publication bias using the fail-safe N statistic. This is the number of non-significant studies that would be necessary to reduce the effect size (ES) to a negligible value of 0.10. This was calculated using the WinPepi statistical package. [21] RESULTS: Study inclusion and characteristics We found more than 100 citations of interest in initial electronic searches, of which 33 papers were potentially relevant and subjected to strict eligibility assessment. Of these, we excluded 8 which did not meet our inclusion criteria and 2 which were duplicate publications (Figure 1). The 23 eligible studies included 13 randomized controlled trials and 10 pre-post studies. Eighteen focused on specific symptoms or symptom clusters while 5 studied general somatic symptoms or clusters of disorders. Although fifteen studies cited specific STPP models, only six studies described manualized treatments and six noted adherence verification. Nine had blinded ratings of outcome. The CCDAN quality ratings averaged 26.5 (SD 7.3, Range 16-36) suggesting moderate study quality. These studies were performed in 10 different countries over the past 25 years. Patients There were a total of 1870 subjects (study range of 10-342), of which 873 (Range 10-87) received STPP and 535 (range 22-257) served as controls. Studies included a mean of 77 (SD 63) patients. Patients averaged 41.3 (SD 10) years of age, and 57.8% (SD 26) were female. Conditions The sample was comprised of 13 different medical conditions affecting various major systems including dermatological, neurological, cardiovascular, respiratory, gastrointestinal, musculoskeletal, genitourinary and immunological systems. Six studies involved patients with chronic pain. Some studies included somatic disorders, such as irritable bowel syndrome and chronic pain, which are known to have moderately strong associations with psychological factors. Others included medical conditions which, though manifested by somatic symptoms, are less clearly linked to emotional dysregulation, such as Crohn’s disease, coronary artery disease, emphysema, bronchitis and Sjrogen’s syndrome. Outcomes The majority of all measured outcomes showed benefits in either RCTs or pre-post studies. Twenty-one (91.3%) reported significant (N=17) or possible (N=4) symptom benefits related to the main physical condition. Eleven of 12 (91.6%) reported significant (N=9) or possible (N=2) social-occupational function improvements. Sixteen of 21 (76.2%) found significant (N=13) or possible (N=3) psychological symptom benefits. Finally, 7 of 9 (77.8%) reported significant (N=6) or possible (N=1) reductions in healthcare utilization. Outcome possibly worse than the control was reported in only the bronchitis/emphysema study [22] on some of the symptom measures. In this study, more STPP patients had stopped smoking, perhaps leading to withdrawal, anxiety or depressive symptoms. Long-term follow up in this set of studies was the norm. Nineteen studies (82.6%) had follow-up of treated cases. The average duration of follow-up was 19.6 (SD 16) months with a range of 1.5 to 60 months. Figure 1: Number of papers yielded by search strategy in systematic review Total papers yielded Abstracts searched electronically for key terms