Effectiveness of a Multicomponent Group-Based Treatment in Patients with Medically Unexplained Physical Symptoms: A Multisite Naturalistic Study

Abstract Psychotherapy is expected to be effective in the treatment of patients with medically unexplained physical symptoms (MUPS). However, evidence is scarce. The aim of this study was to examine the effectiveness of a multicomponent treatment based on group therapy in patients with MUPS in a naturalistic setting and to explore potential predictors of the outcomes. A multisite naturalistic uncontrolled effectiveness study. A total of 290 patients with MUPS participated in group psychotherapy across seven clinical sites. Somatic symptoms, depression, anxiety, general psychotherapy outcomes operationalized as the Outcome Rating Scale (ORS) score, well-being, role functioning interference, as well as a number of pretreatment predictors were measured using a battery of self-report measures. Multilevel modeling and lasso regression with bootstrapping were used for the analysis. Medium to large pre-post effects were found for somatic symptoms, ORS, depression, anxiety, well-being, role functioning interference found in completers after controlling for site and group effects, pretreatment outcome values, and treatment length. Changes reported at 6- and 12-month follow-up were higher for most variables. No substantial pretreatment predictors of the patients’ posttreatment status were found in addition to the pretreatment level of outcome variables. Somatic symptoms seem to be less malleable in psychotherapy than psychological outcome variables. However, there was a trend of further improvement after treatment completion. Registration This study was retrospectively registered with ISRCTN (Identifier 13532466).