Exposure-Based Treatment for Undifferentiated Somatic Symptom Disorder

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