Creating somatic symptoms in the lab : stability and predictive validity of symptoms in the affect and symptom paradigm in a sample from the general population over 18 months

Abstract

Objective: The Affect and Symptom Paradigm (ASP) is an experimental setup that can reliably provoke somatic symptoms in a laboratory setting through the mere presentation of negative pictures. People with persistent somatic symptoms show characteristic effects in this paradigm, including elevated symptom reports and differential brain pattern activation, which suggests that the ASP might be a valuable diagnostic tool. In this cohort study, we tested the temporal stability and ability of the ASP to predict somatic symptom distress over a longer period of time. Methods: We assessed N=91 participants from the general population (69% female) over 2 time points, which were 18 months apart. Participants completed the ASP as well as a questionnaire on somatic symptom distress [Patient Health Questionnaire-15 (PHQ-15)]. Correlation analyses (Bayesian and frequentist) as well as cross-lagged-panel models were used to test the temporal stability and cross-lagged associations. Results: In the cross-lagged-panel models, somatic symptom distress (PHQ-15) at T1 significantly predicted ASP symptom provocation at T2 (β=0.22, p=.029) while controlling for the ASP at T1. Moreover, ASP symptom provocation at T1 significantly predicted cardiorespiratory symptoms (but not overall symptoms) in the PHQ-15 at T2 (β=0.275, p=.019). The autoregressive paths indicated moderate-to-high temporal stability (all β>0.27, all p<.050). Conclusions: The outcome of experimental somatic symptom provocation using the ASP appears stable over time and can significantly predict variability in the experience of cardiorespiratory symptoms (in the PHQ-15) 1.5 years later. Large cohort and intervention studies on chronic somatic symptoms and functional disorders may benefit from including experimental measures such as the ASP.