Objective: It was examined whether unstimulated salivary cortisol levels as a psychobiological marker of stress reactivity correspond to psychological assessments of pain perception, depressive mood, and anxiety in patients with functional gastrointestinal disorder (FGD).
Methods: A total of 30 patients was diagnosed according to the Rome diagnostic criteria for irritable bowel syndrome, nonulcer dyspepsia, or both conditions. Psychometric data were assessed by questionnaires, and salivary samples were collected for the measurement of cortisol levels after awakening and during the day. Patients were grouped by their awakening cortisol levels into low (G1), medium (G2), and high cortisol group (G3).
Results: Psychiatric comorbidity did not differ between the groups. Analysis of variance (ANOVA) showed significant group differences with respect to pain perception and depressive mood, with the highest pain in G1 and the highest depression in G3.
Conclusion: The reported results are in line with prior research on hypothalamus-pituitary-adrenal (HPA) axis dysregulation in patients suffering from somatoform disorders on the one hand (low cortisol levels) and high cortisol levels in depression on the other. It is remarkable that our sample of patients of whom all received the same diagnosis, i.e., FGD, can be subdivided according to functional gastrointestinal symptoms, which correspond to the two types of cortisol alterations. The data provide evidence for psychobiological subgroups in FGD patients. As a consequence, the predominant symptoms reported by patients with FGD should carefully be taken into account to specify (psychotherapeutic) treatment.