ClinicalTrials.gov identifier: NCT02043600.

There is evidence to suggest a role of emotions in placebo and nocebo effects, but whether acute psychological stress changes the magnitude of placebo or nocebo responses has not been tested. In a clinically relevant model of visceroception, we assessed effects of acute psychological stress on changes in urgency and pain in response to positive or negative treatment suggestions. In 120 healthy volunteers, perceived urge-to-defecate and pain in response to individually calibrated rectal distensions were measured with visual analogue scales during a BASELINE. Participants then underwent the Trier Social Stress Test (N = 60) or a simple cognitive task (control, N = 60) and were randomized to positive (placebo), negative (nocebo), or neutral treatment information regarding intravenous administration of saline. The series of distensions was repeated, and changes in visual analogue scales from BASELINE to TEST were compared between groups using analysis of covariance and planned post hoc tests. Treatment information emerged as a main factor (P <0.001), supporting treatment information effects for both urgency and pain. Effects for urgency were modulated by stress (interaction effect: P <0.05): Positive information reduced urgency (P = 0.025), while negative information increased urgency (P = 0.026) only in stressed groups. For pain, effects of stress emerged for nocebo responses, which were only evident in stressed groups (P = 0.009). This is the first experimental study supporting effects of acute psychological stress on placebo and nocebo responses in visceroception. Results call for mechanistic as well as patient studies to assess how psychological stress shapes patients' treatment expectations and thereby affects health outcomes.

No abstract

Patients with ulcerative colitis suffer from impaired health-related quality of life (HrQoL). Comprehensive lifestyle-modification might increase HrQoL and decrease disease activity. Ninety-seven patients in clinical remission with impaired HrQoL were randomly assigned to a 10 week comprehensive lifestyle-modification program (LSM; n = 47; 50.28 ± 11.90 years) or control (n = 50; 45.54 ± 12.49 years) that received a single workshop of intense training in naturopathic self-help strategies. Primary outcome was HrQoL (Inflammatory Bowel Disease Questionnaire; IBDQ) at week 12. Secondary outcomes included IBDQ subscales; generic HrQoL; disease activity and microbiome. Both groups showed improvement in HrQoL from baseline to post-treatment at week 12. The IBDQ sum score showed no significant group difference (p = 0.251). If patients attended more than 50% of the training sessions, a significant group effect (p = 0.034) was evident in favor of LSM. In addition, the SF-36 mental component summary (p = 0.002) was significantly different between the groups in favor of LSM. Disease activity microbiome and adverse events did not differ. Both a single workshop and a 10-week comprehensive lifestyle-modification program can improve HrQoL in patients with ulcerative colitis in remission with no apparent effects on clinical disease activity. A treatment difference was observed when examining a subsample of patients who attended ≥ 50% of sessions.