title: Plasma noradrenaline and state anxiety levels predict placebo response in learned immunosuppression.
abstract: Large interindividual differences exist in the presence and extent of placebo responses in both experimental and clinical studies, but little is known about possible predictors of these responses. We employed a behaviorally conditioned immunosuppression paradigm in healthy men to analyze predictors of learned placebo responses. During acquisition, the subjects received either the immunosuppressant cyclosporin A (n = 32) or a placebo (n = 14) (unconditioned stimuli (US)) together with a novel-tasting drink (conditioned stimulus (CS)). During evocation, the subjects were reexposed to the CS alone. In responders (n = 15), the CS alone caused a significant inhibition of interleukin (IL)-2 production by anti-CD3-stimulated peripheral blood T cells, closely mimicking the drug effect. Nonresponders (n = 17) did not show responses different from those of the controls. Multiple-regression analyses showed that baseline IL-2, plasma noradrenaline, and state anxiety predicted nearly 60% of the variance in the conditioned IL-2 response. These data provide first evidence for putative biological and psychological predictors of learned placebo responses.
authors.affiliation: Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Ober
authors.forename: S
authors.initials: S
authors.lastname: Benson
authors.forename: M
authors.initials: M
authors.lastname: Vogelsang
authors.forename: A
authors.initials: A
authors.lastname: Bylica
authors.forename: D
authors.initials: D
authors.lastname: Günther
authors.forename: O
authors.initials: O
authors.lastname: Witzke
authors.forename: A
authors.initials: A
authors.lastname: Kribben
authors.forename: H
authors.initials: H
authors.lastname: Engler
authors.forename: M
authors.initials: M
authors.lastname: Schedlowski
mesh_terms: D001007:Anxiety / Q000276:immunology / Q000523:psychology*; D003214:Conditioning, Classical / Q000502:physiology*; D016572:Cyclosporine / Q000494:pharmacology*; D006801:Humans; D007165:Immunosuppression Therapy / Q000379:methods / Q000523:psychology*; D007376:Interleukin-2 / Q000097:blood; D008297:Male; D009638:Norepinephrine / Q000097:blood*; D015990:Placebo Effect; D013649:Taste
chemical_list: D007376:Interleukin-2; D016572:Cyclosporine; D009638:Norepinephrine