A longitudinal bifactor approach to modelling somatic symptom development in psychosomatic treatment

Petzke TM, Köteles F, Kessler H, Doering S, Kehyayan A, Pape M, Hofmann T, Rose M, Imbierowicz K, Geiser F, Croy I, Weidner K, Rademacher J, Michalek S, Morawa E, Erim Y, Krakowczyk JB, Teufel M, Heinzmann S, Lahmann C, Peters EMJ, Kruse J, von Boetticher D, Herrmann-Lingen C, Nöhre M, de Zwaan M, Dinger U, Friederich HC, Niecke A, Albus C, Zwerenz R, Beutel M, Roenneberg C, Sattel H, Henningsen P, Stein B, Waller C, Hake K, Spitzer C, Stengel A, Zipfel S, Weimer K, Gündel H, Herpertz S, Witthöft M, Lehnen N (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Book Volume: 204

Article Number: 112577

DOI: 10.1016/j.jpsychores.2026.112577

Abstract

Background Persistent somatic symptoms display a large public health problem and are often treated or addressed alongside other conditions in psychosomatic medicine units. With growing evidence pointing to unfavorable central nervous processing in persistent symptom perception, we aimed at modelling somatic symptom clusters together with an overarching general factor (g-factor) longitudinally during psychosomatic treatment. Methods This study analyses data from the Multicenter Effectiveness Study of Inpatient Psychosomatic-Psychotherapeutic Treatment in German University Hospitals (MEPP, 19 academic psychosomatic medicine departments with inpatient and day clinics, N = 2094 patients with ICD diagnoses between F30 and F69). The PHQ-15 was used to construct bifactor models of symptom perception. We used structural equation models to investigate how the g-factor and symptom-group clusters developed from treatment intake over discharge to a one year follow-up. Factor scores were used to evaluate treatment effects on the individual components. Results As expected, the highest treatment effects, from a bifactor model perspective, were found for the overarching affective-motivational component (ηpart²=0.277) and for fatigue (ηpart²=0.250). All components predicted themselves at future timepoints: autoregressions were high, significant, and explained large proportions of the variance (all β>0.69,p<.001). Conclusions The bifactor model of symptom perception can be longitudinally applied in a large clinical sample with various diagnoses. Psychosomatic treatment showed effects on all components, both those similar to an overarching g-factor and those related to the perception of physiological signals, even when somatic symptoms were not the main target of the treatment.

Authors with CRIS profile

Involved external institutions

Ruhr-Universität Bochum (RUB) Germany (DE) Universitätsklinikum Ulm Germany (DE) Universitätsklinikum Köln Germany (DE) Károli Gáspár University of the Reformed Church in Hungary Hungary (HU) Medizinische Universität Wien Austria (AT) Charité - Universitätsmedizin Berlin Germany (DE) Universitätsklinikum Bonn Germany (DE) Universität Duisburg-Essen (UDE) Germany (DE) Universitätsklinikum Freiburg Germany (DE) Justus-Liebig-Universität Gießen Germany (DE) Universitätsklinikum Göttingen Germany (DE) Medizinische Hochschule Hannover (MHH) / Hannover Medical School Germany (DE) Universitätsklinikum Düsseldorf Germany (DE) Universitätsklinikum Heidelberg Germany (DE) Universitätsmedizin Rostock Germany (DE) Universitätsklinikum Tübingen Germany (DE) Universitätsklinikum Carl Gustav Carus Dresden Germany (DE) Universitätsmedizin der Johannes Gutenberg-Universität Mainz Germany (DE) Technische Universität München (TUM) Germany (DE) Paracelsus Medizinische Privatuniversität, Nürnberg Germany (DE)

How to cite

APA:

Petzke, T.M., Köteles, F., Kessler, H., Doering, S., Kehyayan, A., Pape, M.,... Lehnen, N. (2026). A longitudinal bifactor approach to modelling somatic symptom development in psychosomatic treatment. Journal of Psychosomatic Research, 204. https://doi.org/10.1016/j.jpsychores.2026.112577

MLA:

Petzke, Tara M., et al. "A longitudinal bifactor approach to modelling somatic symptom development in psychosomatic treatment." Journal of Psychosomatic Research 204 (2026).

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