Cognitive-Behavioral Therapy Enriched With Emotion Regulation Training for Multiple Somatoform Symptoms
Condition: Somatic Symptom Disorder (DSM-V)
MeSH terms: Medically Unexplained Symptoms
Study type: Interventional

Summary: 
      The purpose of this study is to evaluate whether cognitive-behavioral therapy enriched with
      strategies from emotion regulation training leads to better improvement in somatic symptoms
      and comorbid problems than cognitive-behavioral therapy alone.
    

Detailed description: 
      Somatic symptoms not caused by a known biomedical condition ("somatoform disorders") are
      highly prevalent, involve a high risk of chronicity, are one of the major reasons for doctor
      visits, and are a tremendous burden for health care systems. Despite the economic relevance,
      research activities are disproportionately low. The only intervention with an evidence grade
      I is cognitive-behavioral therapy (CBT). However, average effect sizes for CBT in
      somatization syndromes are only moderate (Cohen's d < 0.5), and more powerful interventions
      are needed.

      There is convincing evidence that patients with somatoform disorders have emotion regulation
      deficits, which are not addressed by current CBT approaches. Based on positive results of a
      small pilot study it is expected that enriching CBT programs with emotion regulation
      techniques improves treatment outcome. The primary goal of the proposed project is therefore
      to evaluate this hypothesis in a randomized design.

      Patients will be primarily recruited via referrals by primary care doctors. After a screening
      phase a baseline assessments with different self- and clinician-rating scales (see Outcome
      Measures) follows. If participants fulfill the eligibility criteria they will be randomized
      to one of the two study arms: cognitive-behavioral therapy vs. cognitive-behavioral therapy
      enriched with emotion regulation strategies. After every therapy session patients will be
      screened in regard to aspects of therapeutic alliance, adverse events, and symptom
      intensity/annoyance. The post assessment takes place after the 20th session and a follow-up
      is planned six months after post treatment.

      Different methods will be applied to prevent bias and to assure a high quality level of the
      current study. Data handling, data monitoring and statistical analyses will be supervised by
      the Coordinating Center for Clinical Trials (KKS) of Philipps-University of Marburg; data
      quality and safety principles will be applied. Additionally an independent Data Safety
      Monitoring Board will be nominated. The study center will visit all study sites regularly to
      verify correct procedures, data sampling, and data management. Randomisation occurs and is
      controlled centrally through the randomisation's central office in KKS Marburg. Furthermore
      the current study constitutes a single-blinded trial. Assessment interviews are conducted and
      analyzed by people blinded to the treatment condition. Additionally, treatments are
      manualized, and therapists receive an intense training. Treatment fidelity/integrity is
      analyzed with rating schemes for 5% randomly selected videotaped treatment sessions. Allowed
      additional treatments during study inclusion are thoroughly monitored and analyzed.

      The sample size calculation is based on the primary outcome variable "somatization severity
      index" of the Screening of Somatoform Disorders (SOMS-7T). Based on results of the main
      validation study of SOMS-7T, meta-analytic estimations, and results of a pilot study of the
      efficacy of ENCERT, the power calculations yield a necessary total sample size of N=194 to
      detect a clinical relevant difference of 4 points symptom reduction on SOMS-7T between the
      two treatments with a power of 0.80 and an alpha=.05. With regard to an estimated drop-out
      rate of 20%, N=244 patients are to be recruited.

      As main efficacy analysis the primary outcome shall be analyzed with linear mixed-effect
      models. It will be done according to the Intention-to-Treat (ITT) principle: to consider
      missing values as a potential source of bias, they will be handled according to the framework
      by Rubin. Secondary statistical analyses focus on establishing longer term treatment efficacy
      and describing the pattern of change. For this purpose the mean response will be modeled as a
      function of time with a separate mixed effects linear model over all assessments.
      Furthermore, interindividual differences in intraindividual change will be modeled using
      multilevel analysis for longitudinal data. Multilevel longitudinal mediation analyses will be
      conducted in order to test whether the effect of treatment condition on intraindividual
      changes in somatic symptom severity can be explained by intraindividual changes in emotion
      regulation skills.
    

Intervention name(s): Cognitive-behavioral therapy + emotion regulation training for patients with multiple somatoform symptoms; Cognitive-behavioral therapy for patients with multiple somatoform symptoms
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Cognitive-behavioral therapy + emotion regulation training for patients with multiple somatoform symptoms:
20 weekly sessions individual therapy (à 50) minutes; Cognitive-behavioral therapy for patients with multiple somatoform symptoms:
20 weekly sessions individual therapy (à 50) minutes
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: somatoform symptoms; somatic symptoms; somatoform disorder; somatic symptom disorder; cognitive-behavioral therapy; emotion regulation training