An interventional study of Exposure in Somatic Symptom Disorder, sponsored by Karolinska Institutet. Completed at 1 site in Sweden. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-03-19.
Sponsored by Karolinska Institutet · Not applicable, Interventional, and Treatment
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.
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.
Exclusion Criteria:
Eight weeks of therapist-guided exposure-based treatment delivered via the Internet.
Behavioral: Exposure
Systematic confrontation with stimuli associated with symptom-related distress, to achieve therapeutic changes in cognitions or behavior
Feasibility 1: Distribution of Physical Symptoms
According to the Patient Health Questionnaire-15 (PHQ-15, theoretical range: 0-30, higher score indicates more distressing physical symptoms)
Time frame: Pre-treatment assessment (within 2 weeks before treatment)
Feasibility 2: Credibility/Expectancy Based on the Credibility/Expectancy Scale
Theoretical range: 0-50, higher score indicates higher credibility/expectancy
Time frame: Week 3 of treatment
Feasibility 3: Adherence to the Protocol #1: Percentage Completed Modules in the Sample as a Whole
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.
Time frame: Adherence data collected over the entire course of the treatment, up to 8 weeks.
Feasibility 4: Patient-reported Adequacy of Rationale as Assessed Using a Questionnaire Developed Specifically for This Purpose (Theoretical Range: 0-10)
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
Time frame: Post-treatment assessment (immediately after treatment, completed within 45 days)
Feasibility 5: Adequacy of the Measurement Strategy
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 \["Extremely stressful/bothering"\])
Time frame: Post-treatment assessment (immediately after treatment, completed within 45 days)
Feasibility 6: Satisfaction With Treatment as Indicated by a Mean Client Satisfaction Questionnaire (CSQ-8) Score of at Least 22
Theoretical range: 8-32, higher score indicates higher satisfaction. This sum score is based on 8 items, each scored 1-4.
Time frame: Post-treatment assessment (immediately after treatment, completed within 45 days)
Feasibility 7a: Adverse Events Measured Using Free-text Items #1: Total Number of Reported Events
The respondent was instructed to describe up to three adverse events.
Time frame: Post-treatment assessment (immediately after treatment, completed within 45 days)
Feasibility 7b: Adverse Events Measured Using the 20-item Negative Effects Questionnaire (NEQ-20)
Theoretical range: 0-80, higher score indicates more severe adverse events
Time frame: Post-treatment assessment (immediately after treatment, completed within 45 days)
Feasibility 3: Adherence to the Protocol #2: Percentage of Participants Completing at Least 2 Exposure Exercises
Preregistered target: at least 50% of participants completing at least 2 exposure exercises
Time frame: Adherence data collected over the entire course of the treatment, up to 8 weeks.
Feasibility 7a: Adverse Events Measured Using Free-text Items #2: Number of Participants Who Reported at Least One Adverse Event
The respondent was instructed to describe up to three adverse events.
Time frame: Post-treatment assessment (immediately after treatment, completed within 45 days)
Patient Health Questionnaire-15 (PHQ-15)
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
Time frame: 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
Somatic Symptom Disorder-B Criteria Scale (SSD-12)
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
Time frame: 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
Symptom Preoccupation Scale (Preliminary Scale)
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.
Time frame: 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
14-item Health Anxiety Inventory (HAI-14)
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
Time frame: Screening, pre-treatment assessment (within 2 weeks before treatment), Post-treatment assessment (immediately after treatment, completed within 45 days), 3 months after treatment
Anxiety Sensitivity Index (ASI)
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
Time frame: 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
GAD-7
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
Time frame: 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
Patient Health Questionnaire (PHQ-9)
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
Time frame: 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
12-item WHO Disability Assessment Schedule 2.0 (WHODAS 2.0)
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
Time frame: Screening, pre-treatment assessment (within 2 weeks before treatment), post-treatment assessment (immediately after treatment, completed within 45 days), 3 months after treatment
Alcohol Use Disorders Identification Test (AUDIT)
Theoretical range: 0-40, higher score indicates more problematic alcohol use
Time frame: Screening only
Drug Use Disorders Identification Test (DUDIT)
Theoretical range: 0-44, higher score indicates more problematic substance use
Time frame: Screening only
Working Alliance Inventory (WAI)
Theoretical range: 6-42, higher score indicates better relationship with the therapist
Time frame: Week 3 of treatment
We originally aimed to recruit 40 participants for 80% power in two-sided tests of moderate effects (d=0.5) on efficacy outcomes measured at two time points, given a 5% alpha and 15% missing data at post-treatment. In light of the high data retention, prior to the data analysis, we ended the recruitment with 33 participants included in November 2020.
| Milestone | Internet-delivered Exposure-based Treatment |
|---|---|
| Started | 33 |
| Completed | 32 |
| Not completed | 1 |
According to the Patient Health Questionnaire-15 (PHQ-15, theoretical range: 0-30, higher score indicates more distressing physical symptoms)
| score on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Feasibility 1: Distribution of Physical Symptoms | 11.8 (3 to 20) |
Theoretical range: 0-50, higher score indicates higher credibility/expectancy
| score on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Feasibility 2: Credibility/Expectancy Based on the Credibility/Expectancy Scale | 34.5 ± 7.0 |
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.
| Modules | Internet-delivered Exposure-based Treatment |
|---|---|
| Feasibility 3: Adherence to the Protocol #1: Percentage Completed Modules in the Sample as a Whole | 150 |
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
| score on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Feasibility 4: Patient-reported Adequacy of Rationale as Assessed Using a Questionnaire Developed Specifically for This Purpose (Theoretical Range: 0-10) | 8.4 ± 1.5 |
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 \["Extremely stressful/bothering"\])
| Participants | Internet-delivered Exposure-based Treatment |
|---|---|
| Missing data at post-treatment | 1 |
| Found the measurement strategy acceptable (no cause for distress) | 27 |
Theoretical range: 8-32, higher score indicates higher satisfaction. This sum score is based on 8 items, each scored 1-4.
| score on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Feasibility 6: Satisfaction With Treatment as Indicated by a Mean Client Satisfaction Questionnaire (CSQ-8) Score of at Least 22 | 25.3 ± 4.7 |
The respondent was instructed to describe up to three adverse events.
| adverse events | Internet-delivered Exposure-based Treatment |
|---|---|
| Feasibility 7a: Adverse Events Measured Using Free-text Items #1: Total Number of Reported Events | 6 |
Theoretical range: 0-80, higher score indicates more severe adverse events
| score on scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Feasibility 7b: Adverse Events Measured Using the 20-item Negative Effects Questionnaire (NEQ-20) | 5.7 ± 8.2 |
Preregistered target: at least 50% of participants completing at least 2 exposure exercises
| Participants | Internet-delivered Exposure-based Treatment |
|---|---|
| Feasibility 3: Adherence to the Protocol #2: Percentage of Participants Completing at Least 2 Exposure Exercises | 32 |
The respondent was instructed to describe up to three adverse events.
| Participants | Internet-delivered Exposure-based Treatment |
|---|---|
| Feasibility 7a: Adverse Events Measured Using Free-text Items #2: Number of Participants Who Reported at Least One Adverse Event | 5 |
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
| units on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Patient Health Questionnaire-15 (PHQ-15) | -4.2 (-5.5 to -2.9) |
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
| Likert scale units | Internet-delivered Exposure-based Treatment |
|---|---|
| Somatic Symptom Disorder-B Criteria Scale (SSD-12) | -13.0 (-16.5 to -9.4) |
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.
Results for this outcome have not been posted.
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
| Likert scale units | Internet-delivered Exposure-based Treatment |
|---|---|
| 14-item Health Anxiety Inventory (HAI-14) | -6.7 (-9.3 to -4.2) |
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
| Likert scale units | Internet-delivered Exposure-based Treatment |
|---|---|
| Anxiety Sensitivity Index (ASI) | -9.5 (-13.1 to -6.0) |
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
| Likert scale units | Internet-delivered Exposure-based Treatment |
|---|---|
| GAD-7 | -3.4 (-5.0 to -1.7) |
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
| units on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Patient Health Questionnaire (PHQ-9) | -3.2 (-4.6 to -1.8) |
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
| units on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| 12-item WHO Disability Assessment Schedule 2.0 (WHODAS 2.0) | -8.8 (-13.0 to -4.6) |
Theoretical range: 0-40, higher score indicates more problematic alcohol use
| score on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Alcohol Use Disorders Identification Test (AUDIT) | 4.7 ± 5.7 |
Theoretical range: 0-44, higher score indicates more problematic substance use
| score on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Drug Use Disorders Identification Test (DUDIT) | 0.2 ± 0.8 |
Theoretical range: 6-42, higher score indicates better relationship with the therapist
| score on a scale | Internet-delivered Exposure-based Treatment |
|---|---|
| Working Alliance Inventory (WAI) | 35.2 ± 5.7 |
Collected over 8-week treatment period. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Internet-delivered Exposure-based Treatment | 0/33 (0%) | 0/33 (0%) | 5/32 (15.6%) |
| Event | Internet-delivered Exposure-based Treatment |
|---|---|
| increased anxiety, stress or distressPsychiatric disorders | 3/32 |
| a negative outlook on the future caused by poor treatment outcomePsychiatric disorders | 1/32 |
| distress caused by conflicting information on how to optimise the effect of meditationPsychiatric disorders | 1/32 |
| Age, Continuous(years) | Internet-delivered Exposure-based Treatment |
|---|---|
| Mean | 46 ± 14 |
| Sex: Female, Male(Participants) | Internet-delivered Exposure-based Treatment |
|---|---|
| Female | 22 |
| Male | 11 |
| Race and Ethnicity Not Collected(Participants) | Internet-delivered Exposure-based Treatment |
|---|
| Region of Enrollment(participants) | Internet-delivered Exposure-based Treatment |
|---|---|
| Sweden | 33 |
| University education(Participants) | Internet-delivered Exposure-based Treatment |
|---|---|
| Count of participants | 27 |
| Employment(Participants) | Internet-delivered Exposure-based Treatment |
|---|---|
| Working full-time | 21 |
| Working part-time (<90%) | 7 |
| Retired | 4 |
| Student | 1 |
Documents are hosted by the registry — open the source record to download them.
Plan to share: No — We are willing to consider reasonable requests for individual participant data (IPD) and to consult the responsible parties accordingly. However, we do not expect to be granted permission to share IPD as long as, under Swedish and European Union (EU) data protection and privacy legislation, the IPD constitutes personal data meaning that it is possible to, using the study database, link the IPD to an identifiable living natural person.
This study is completed, as verified in Mar 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Medically Unexplained Symptoms→
Karolinska Institutet