“Exploring temporal relationships among worrying, anxiety, and somatic symptom”

Little is known about the role of anxiety in the development of functional somatic symptoms (FSS). FSS may be triggered by or give rise to symptoms of anxiety. This study used intensive longitudinal measurement of daily experienced anxiety and somatic symptoms to increase our insight into the relations between somatic symptoms and anxiety within individuals, and explore mechanisms that could contribute to FSS. The present study included 767 participants (83% females, mean age 39 years), who were recruited through an online crowdsourcing study in the Dutch general population. Somatic symptoms and symptoms of anxiety were reported thrice daily (6-h intervals) for 30 days using electronic diaries. We found substantial heterogeneity in terms of these within-person processes. Only in a small number of individuals from the general population, an increase in symptoms of anxiety was associated with an increase in somatic symptoms, or vice versa, six hours later. We found no support that these effects were related to having higher levels of FSS.


There is a growing interest in how intensive longitudinal data collected by means of electronic diaries can contribute to identification of person tailored explanatory models of disease. Our paper shows that both accurately capturing these within-person processes and extensive individual differences with regards to these processes provide great challenges before the goal of personalized modeling can be reached. However, the observed heterogeneity in these individual processes may already help in promoting awareness among clinicians, which represents a first step in achieving more personalized treatment of functional somatic symptoms.

Dr. van Gils and Dr. Groen are giving their award winning lecture on Friday, June 4, 2021 at 7pm CEST.