This study tested whether functional somatic symptoms are associated with exaggerated increases in self-reported anxiety and somatic complaints in response to stress and CO2-enriched air breathing, and whether this association exists in parallel to or in the absence of exaggerated physiological responses.
Out of 499 young somatically healthy undergraduate women, 18 participants high in functional somatic symptoms (HSS group) and 18 participants low in symptoms (LSS) were selected. They were submitted to mental stress, mild physical exercise and relaxation during conditions of normal breathing, breathing compressed normal air, and breathing compressed 5% CO2-enriched air. In all conditions, self-reported anxiety and somatic symptoms and respiratory and autonomic responses were assessed.
HSS participants reported, as compared to LSS, more tenseness, anxiety, and somatic symptoms at baseline and increased responses to mental stress and during 5% CO2 breathing, but not in response to exercise. However, no evidence was found for a corresponding exaggerated respiratory or autonomic response.
A young, female, and nonclinical population with numerous functional somatic symptoms and high levels of anxiety is characterized by an exaggerated perception of a normal physiological response.