Bodily Distress Disorder, Psychological Factors Affecting Other Medical Conditions, Somatic Symptom and Related Disorders
Conditions
Keywords
exposure therapy, primary care, dismantling trial, persistent physical symptoms
Brief summary
It is unclear to what degree systematic exposure exercises contribute to the overall effects of exposure therapy (exposure and response prevention). This trial recruits individuals with high somatic symptom burden or reactivity to symptoms who, based on previous work, are likely to benefit specifically from exposure therapy. The aim of the study is to evaluate to what degree the effect of exposure therapy for this group is driven by the addition of structured exposure exercises to response prevention. This will be evaluated on the basis of a randomized controlled trial (N=360) where participants are enrolled either in response prevention (n=180), or exposure and response prevention (n=180). Primary outcome will be the between-group differences in the reduction in reactivity to symptoms, as measured week-by-week using the somatic symptom disorder B-criteria scale (SSD-12). Results from this project will be informative for exposure-based and various multicomponent behavioral treatments for individuals with persistent physical symptoms worldwide.
Detailed description
Persistent physical symptoms refers to somatic complaints that persist for months or more and give rise to significant distress, regardless of etiology. Common complaints such as gastrointestinal symptoms, fatigue, and pain have been estimated to account for up to half of primary care consultations, can be difficult to classify, and often defy straightforward medical explanation. In light of substantial personal and socioeconomic repercussions, effective clinical interventions are needed. The investigators recently completed a randomized controlled trial in primary care (SOMEX1) where individuals with persistent physical symptoms were randomized to 10 weeks of exposure therapy or healthy lifestyle promotion. Based on that trial, exposure therapy appears to have a small average advantage over healthy lifestyle promotion in mean effect on symptom preoccupation, i.e., the patient's tendency to respond strongly to, and engage in behaviors contingent on, somatic symptoms, and also on patient satisfaction. In line with a priori hypotheses, this added effect on symptom preoccupation was larger, and an advantage in the effect on somatic symptom burden was also seen, when patients reported a very high general somatic symptom burden or symptom preoccupation before treatment. For example, a patient with a PHQ-15 score of 10 could expect a near-zero added effect of exposure therapy on somatic symptom burden (d = 0.08) and a small added effect on symptom preoccupation (d = 0.31), whereas a patient with a PHQ-15 score of 15 could expect a small to moderate added effect on somatic symptom burden (d = 0.37) and a moderate added effect on symptom preoccupation (d = 0.62). An unexpected finding, however, was that in exposure therapy, the correlation between the participant's number of exposure exercises and reduction in symptom preoccupation was weak (rs=0.21-0.26). This highlights the fact that it is yet unclear to what degree the two main components of exposure therapy - exposure and response prevention - contribute to the treatment effects. It is also unclear what patient- and contextual factors moderate the added effect of exposure. The aim of the present project is to focus on the aforementioned subgroup of patients who benefit specifically from exposure therapy, and to determine to what degree this is driven by the addition of exposure to response prevention. This will be evaluated on the basis of a randomized controlled trial (N=360; SOMEX2) where participants with a high general somatic symptom burden or high symptom preoccupation are enrolled in response prevention (n=180), or exposure and response prevention (n=180). Primary outcome will be between-group differences in the reduction in symptom preoccupation as measured week-by-week using the somatic symptom disorder B-criteria scale (SSD-12). The participants will be blinded to the study design and the hypotheses of the investigators. Results from this project will be informative for exposure-based and various multicomponent behavioral treatments for primary care patients with persistent physical symptoms worldwide. \- Primary research question: Is there a significant average advantage, d≥0.30, of exposure and response prevention, as compared to response prevention only, with regard to the reduction in symptom preoccupation (SSD-12) up to the post-treatment assessment? Hypothesis: Yes. \- Key secondary research questions: Is the average advantage of adding exposure to response prevention moderated by the frequency of opportunities for response prevention as measured at baseline? Hypothesis: Yes, more opportunities are predictive of a smaller added effect of exposure exercises. Is the average advantage of adding exposure to response prevention moderated by the temporality of unwanted outcomes as measured at baseline? Hypothesis: Yes, more distal unwanted outcomes are predictive of a larger added effect of exposure exercises. Is the average advantage of adding exposure to response prevention moderated by anxiety sensitivity - i.e., reactivity to physiological arousal - at baseline? Hypothesis: Yes, a higher anxiety sensitivity is predictive of a larger added effect of exposure exercises. Which additional variables act as moderators and mediators of added effects (below)? Are there average advantages of adding exposure (superiority, ds≥0.30) with regard to general somatic symptom burden, core depressive symptoms, or functional impairment? Hypothesis: No. What is the cost-effectiveness of exposure and response prevention versus response prevention? Exploratory analyses.
Interventions
BEHAVIORALPlanned, systematic, exposure exercises
Exposure exercises, planned on the basis of functional analysis. Participants are encouraged to evaluate the relevance of-, and if so work continuously with-, interceptive, in vivo, and imaginal exposure exercises which are planned at specific timepoints.
BEHAVIORALResponse prevention
Response prevention, planned on the basis of functional analysis. Participants make a plan to reduce presumably negatively reinforced behavior contingent on somatic symptoms and distress related to somatic symptoms.
Sponsors
Region Stockholm
Karolinska Institutet
Stockholm University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
Blinding to trial design, but not assigned intervention.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Bothered by at least one somatic symptom for at least 4 months. * High symptom burden, defined as a PHQ-15≥15 or SSD-12≥25. * Adult (≥18 years old). * Living in Stockholm County (catchment area of the clinic). * Sufficient technical knowledge with web-enabled device and fluent in Swedish. * Complete pre-treatment assessment.
Exclusion criteria
* A maximum of half the sample (180 participants) will be included with health anxiety, i.e., a fear of or preoccupation with serious illness, as their principal clinical problem. * Clinical picture dominated by non-somatoform psychiatric disorder such as depression, panic disorder, or primary insomnia. Comorbidities are allowed. * Severe psychiatric condition (e.g., ongoing manic episode, psychotic disorder, severe depression) or markers for suicidality beyond sporadic ideation. * Clear medical risk in taking part in exposure-based treatment (e.g., pregnancy), or somatic condition, or treatment for somatic condition, makes treatment unfeasible. * Continuous psychotropic medication (antidepressants, anticonvulsants, mood-stabilizers, antipsychotics) is present and has either not been stable for at least 4 weeks, or is not expected to remain stable. * Other psychotherapy or planned absence \>1 week during intended main phase.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Somatic Symptom Disorder-B Criteria Scale (SSD-12) | Change over the main phase, as modeled using data from all 11 assessments from the baseline assessment to the primary endpoint (≤45 days after treatment). Additional analyses incorporate 6- and 12-months follow-up assessments. | Theoretical range: 0-48. A higher score indicates higher degree of reactivity to symptoms. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Somatic Symptom Scale 8 (SSS-8) | Change over the main phase, as modeled using data from all 11 assessments from the baseline assessment to the primary endpoint (≤45 days after treatment). Secondary analyses incorporate 6- and 12-months follow-up assessments. | Theoretical range: 0-32. A higher score indicates a higher subjective somatic symptom burden. |
| GAD-7 | Change over the main phase, as modelled using data from the baseline assessment and primary endpoint (≤45 days after treatment). Additional analyses incorporate 6- and 12-months follow-up assessments. | Theoretical range: 0-21. A higher score indicates more general anxiety. |
| Patient Health Questionnaire 9 (PHQ-9) | Change over the main phase, as modelled using data from the baseline assessment and primary endpoint (≤45 days after treatment). Additional analyses incorporate 6- and 12-months follow-up assessments. | Theoretical range: 0-27. A higher score indicates more symptoms of depression. |
| 12-item WHO Disability Assessment Schedule 2.0 (WHODAS 2.0) | Change over the main phase, as modeled using data from the baseline assessment and primary endpoint (≤45 days after treatment). Additional analyses incorporate 6- and 12-months follow-up assessments. | Theoretical range: 0-100. A higher score indicates more disability. |
| Seven questions probing into basic emotions related to somatic symptoms | Change over the main phase, as modeled using data from the baseline assessment and primary endpoint (≤45 days after treatment). | For each emotion (anger, disgust, fear, joy, sadness, shame, surprise), theoretical range: 0-10. A higher score indicates presence of emotion. |
| 14-item Health Anxiety Inventory (HAI-14) | Change over the main phase, as modelled using data from the baseline assessment and primary endpoint (≤45 days after treatment). | Theoretical range: 0-42. A higher score indicates more health anxiety. |
| Adapted 11-item version of the Catastrophizing about Asthma Scale (CAS) | Change over the main phase, as modelled using data from the baseline assessment and primary endpoint (≤45 days after treatment). | Domain-specific outcome, for participants with a mean score of at least 1 on the PHQ-15 cardiopulmonary domain. Theoretical range: 0-44. A higher score indicates more reactivity to cardiopulmonary symptoms. |
| Reactivity to fatigue (study-specific) | Change over the main phase, as modelled using data from the baseline assessment and primary endpoint (≤45 days after treatment). | Domain-specific outcome, for participants with a mean score of at least 1 on the PHQ-15 fatigue domain. Theoretical range: not yet finalized. A higher score indicates more reactivity to fatigue. |
| Visceral Sensitivity Index (VSI) | Change over the main phase, as modelled using data from the baseline assessment and primary endpoint (≤45 days after treatment). | Domain-specific outcome, for participants with a mean score of at least 1 on the PHQ-15 gastrointestinal domain. Theoretical range: 0-75. A higher score indicates reactivity to gastrointestinal symptoms |
| Pain Catastrophizing Scale (PCS) | Change over the main phase, as modelled using data from the baseline assessment and primary endpoint (≤45 days after treatment). | Domain-specific outcome, for participants with a mean score of at least 1 on the PHQ-15 pain domain. Theoretical range: 0-52. A higher score indicates more reactivity to pain. |
Countries
Sweden
Contacts
CONTACTErland Axelsson, PhD
PRINCIPAL_INVESTIGATORErland Axelsson, PhD
Region Stockholm and Karolinska Institutet
Outcome results
None listed