Exposure-Based Treatment for Undifferentiated Somatic Symptom Disorder

Not Applicable

Completed

Conditions: Somatic Symptom Disorder

Interventions: Behavioral: Exposure

Registration Number: NCT04511286

Lead Sponsor: Karolinska Institutet

Brief Summary: This study investigates the feasibility of a general exposure-based treatment protocol that is intended to work for a large variety of patient groups with a clinically significant preoccupation with physical symptoms. This is a prospective single-group study based at Karolinska Institutet, Stockholm, Sweden, where 40 adults with DSM-5 somatic symptom disorder are enrolled in 8 weeks of therapist-guided exposure-based treatment via the Internet. Exposure is based on general principles but tailored to suit the needs of each patient. Outcomes include patient-reported credibility and expectancy, adherence to the treatment protocol, client satisfaction, and negative events. Within-group effects will also be quantified and discussed in relation to the existing literature.

Detailed Description: Background:

A substantial portion of patients in routine care suffer from a recurrent preoccupation with physical symptoms, which often leads to substantial suffering and impairment. Exposure-based treatment - where the patient systematically seeks out that which gives rise to unwanted sensations, cognitions, or behavior - has been found to lead to beneficial effects in several types of symptom preoccupation. Yet, this form of treatment is rarely offered in routine care. This may be partially because existing treatment protocols have been developed for specific symptom clusters (e.g., functional somatic syndromes such as irritable bowel syndrome and fibromyalgia) or specific unwanted responses to symptoms (e.g., the fear of having a severe illness), and that many clinics do not have the resources to offer all these specialized protocols in parallel. An alternative approach could be to base exposure treatment on a more general protocol that may be tailored to suit a larger variety of patient groups who suffer from a recurrent preoccupation with physical symptoms. However, it is yet unclear if the use of such a general treatment protocol for symptom preoccupation would be feasible, for example in terms of patient-reported credibility, adherence, identification with the rationale, and general client satisfaction.

Aim:

To investigate the feasibility of delivering exposure-based treatment using a general protocol for clinically significant symptom preoccupation, without selecting patients based on any specific symptom cluster (such as a functional somatic syndrome) or specific unwanted response to physical symptoms (such as a frequent fear of illness).

Design:

This is a prospective single-group feasibility study based at Karolinska Institutet, Stockholm, Sweden, where 40 adults with somatic symptom disorder according to the Diagnostic and statistical manual of mental disorders 5 (DSM-5) are enrolled in 8 weeks of therapist-guided exposure-based treatment that is delivered via the Internet. Various aspects of feasibility are assessed; most notably: patient-reported credibility and expectancy, adherence to the treatment protocol, client satisfaction, and negative events. Within-group effects are also quantified.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 33

Inclusion Criteria

DSM-5 somatic symptom disorder
Interest in 8-week intensive psychological treatment to reduce distress and the impact of physical symptoms
At least 18 years old
Living in Sweden
Fluent in Swedish
Complete pre-treatment assessment

Exclusion Criteria

Preoccupation with physical symptoms better explained by another psychiatric condition such as illness anxiety disorder, panic disorder, or obsessive-compulsive disorder
Severe psychiatric condition, such as bipolar disorder, suicidal ideation, or psychosis
Medical risks associated with participating in exposure-based treatment, or somatic condition - or treatment for somatic condition - that is an obstacle to participating in exposure-based treatment
Non-stable continuous pharmacotherapy (dosage changed during the past 4 weeks) and the drug is likely to affect outcome measures (primarily: antidepressants, anticonvulsants, benzodiazepines, nonbenzodiazepines, opioids)
Alcohol or substance use that is a clear obstacle to therapy
Planned absence for more than 1 week of the treatment period

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Internet-delivered exposure-based treatment	Exposure	Eight weeks of therapist-guided exposure-based treatment delivered via the Internet.

Primary Outcome Measures

Name	Time	Method
Feasibility 1: Distribution of Physical Symptoms	Pre-treatment assessment (within 2 weeks before treatment)	According to the Patient Health Questionnaire-15 (PHQ-15, theoretical range: 0-30, higher score indicates more distressing physical symptoms)
Feasibility 2: Credibility/Expectancy Based on the Credibility/Expectancy Scale	Week 3 of treatment	Theoretical range: 0-50, higher score indicates higher credibility/expectancy
Feasibility 3: Adherence to the Protocol #1: Percentage Completed Modules in the Sample as a Whole	Adherence data collected over the entire course of the treatment, up to 8 weeks.	Preregistered target: at least 60% completed modules in the sample as a whole. In this study, all participants were enrolled in the same type of treatment and were thus offered to work with the same treatment modules. This outcome was the proportion of modules completed in total by all participants, out of the total modules available to all participants.
Feasibility 4: Patient-reported Adequacy of Rationale as Assessed Using a Questionnaire Developed Specifically for This Purpose (Theoretical Range: 0-10)	Post-treatment assessment (immediately after treatment, completed within 45 days)	From 0 ("not at all relevant") to 10 ("extremely relevant"). Was originally intended to be administered at week 3, but was administered post-treatment due to an administrative error
Feasibility 7b: Adverse Events Measured Using the 20-item Negative Effects Questionnaire (NEQ-20)	Post-treatment assessment (immediately after treatment, completed within 45 days)	Theoretical range: 0-80, higher score indicates more severe adverse events
Feasibility 5: Adequacy of the Measurement Strategy	Post-treatment assessment (immediately after treatment, completed within 45 days)	Preregistered target: less than 30% missing data at post-treatment, and at least 75% finding the measurement strategy acceptable (less than 7 on a scale from 0 \["Not at all stressful/bothering"\] to 10 \["Extremely stressful/bothering"\])
Feasibility 6: Satisfaction With Treatment as Indicated by a Mean Client Satisfaction Questionnaire (CSQ-8) Score of at Least 22	Post-treatment assessment (immediately after treatment, completed within 45 days)	Theoretical range: 8-32, higher score indicates higher satisfaction. This sum score is based on 8 items, each scored 1-4.
Feasibility 7a: Adverse Events Measured Using Free-text Items #1: Total Number of Reported Events	Post-treatment assessment (immediately after treatment, completed within 45 days)	The respondent was instructed to describe up to three adverse events.
Feasibility 3: Adherence to the Protocol #2: Percentage of Participants Completing at Least 2 Exposure Exercises	Adherence data collected over the entire course of the treatment, up to 8 weeks.	Preregistered target: at least 50% of participants completing at least 2 exposure exercises
Feasibility 7a: Adverse Events Measured Using Free-text Items #2: Number of Participants Who Reported at Least One Adverse Event	Post-treatment assessment (immediately after treatment, completed within 45 days)	The respondent was instructed to describe up to three adverse events.

Secondary Outcome Measures

Name	Time	Method
Anxiety Sensitivity Index (ASI)	Screening, pre-treatment assessment (within 2 weeks before treatment), post-treatment assessment Post-treatment assessment (immediately after treatment, completed within 45 days), 3 months after treatment	Change pre-post, as derived from linear mixed effects regression models fitted by maximum likelihood estimation using data from all 33 participants, and fitted on all 11 measurement points over the treatment phase (from pre-treatment to post-treatment). Theoretical range: 0-64, higher score indicates more anxiety sensitivity
GAD-7	Pre-treatment assessment (within 2 weeks before treatment), post-treatment assessment Post-treatment assessment (immediately after treatment, completed within 45 days), 3 months after treatment	Change pre-post, as derived from linear mixed effects regression models fitted by maximum likelihood estimation using data from all 33 participants, and fitted on all 11 measurement points over the treatment phase (from pre-treatment to post-treatment). Theoretical range: 0-21, higher score indicates more general anxiety
Patient Health Questionnaire (PHQ-9)	Screening, pre-treatment assessment (within 2 weeks before treatment), weekly during treatments (suicidality), post-treatment assesment (immediately after treatment, completed within 45 days), 3 months after treatment	Change pre-post, as derived from linear mixed effects regression models fitted by maximum likelihood estimation using data from all 33 participants, and fitted on all 11 measurement points over the treatment phase (from pre-treatment to post-treatment). Theoretical range: 0-27, higher score indicates more symptoms of depression
Drug Use Disorders Identification Test (DUDIT)	Screening only	Theoretical range: 0-44, higher score indicates more problematic substance use
Alcohol Use Disorders Identification Test (AUDIT)	Screening only	Theoretical range: 0-40, higher score indicates more problematic alcohol use
Symptom Preoccupation Scale (Preliminary Scale)	Screening, pre-treatment assessment (within 2 weeks before treatment), weekly during treatment, Post-treatment assessment (immediately after treatment, completed within 45 days), 3 months after treatment	Under development, higher score indicates higher degree of preoccupation with symptoms. This is to be regarded as an item pool that will be further analyzed in 2024-2025, and in conjunction with data from other clinical trials. As of September 2023, it is therefore not yet possible to provide a theoretical range for this scale, and it is also not possible to provide outcomes.
14-item Health Anxiety Inventory (HAI-14)	Screening, pre-treatment assessment (within 2 weeks before treatment), Post-treatment assessment (immediately after treatment, completed within 45 days), 3 months after treatment	Change pre-post, as derived from linear mixed effects regression models fitted by maximum likelihood estimation using data from all 33 participants, and fitted on all 11 measurement points over the treatment phase (from pre-treatment to post-treatment). Theoretical range: 0-42, higher score indicates more health anxiety
Patient Health Questionnaire-15 (PHQ-15)	Screening, pre-treatment assessment (within 2 weeks before treatment), weekly during treatment, Post-treatment assessment (immediately after treatment, completed within 45 days), 3 months after treatment	Change pre-post, as derived from linear mixed effects regression models fitted by maximum likelihood estimation using data from all 33 participants, and fitted on all 11 measurement points over the treatment phase (from pre-treatment to post-treatment). Theoretical range: 0-30, higher score indicates more distressing physical symptoms
Working Alliance Inventory (WAI)	Week 3 of treatment	Theoretical range: 6-42, higher score indicates better relationship with the therapist
Somatic Symptom Disorder-B Criteria Scale (SSD-12)	Screening, pre-treatment assessment (within 2 weeks before treatment), weekly during treatment, Post-treatment assessment (immediately after treatment, completed within 45 days), 3 months after treatment	Change pre-post, as derived from linear mixed effects regression models fitted by maximum likelihood estimation using data from all 33 participants, and fitted on all 11 measurement points over the treatment phase (from pre-treatment to post-treatment). Theoretical range: 0-48, higher score indicates higher degree of preoccupation with symptoms
12-item WHO Disability Assessment Schedule 2.0 (WHODAS 2.0)	Screening, pre-treatment assessment (within 2 weeks before treatment), post-treatment assessment (immediately after treatment, completed within 45 days), 3 months after treatment	Change pre-post, as derived from linear mixed effects regression models fitted by maximum likelihood estimation using data from all 33 participants, and fitted on all 11 measurement points over the treatment phase (from pre-treatment to post-treatment). Theoretical range: 0-100, higher score indicates more disability