Relationship between trauma load and GRα isoform expression.

<p>(A) Number of different traumatic event types, (B) PTSD symptom severity, and (C) GRα mRNA expression levels in non-PTSD subjects with no or few traumatic experiences (0–3 traumatic event types; <i>low trauma-exposed non-PTSD</i>; <i>n</i> = 20), in non-PTSD subjects with substantial exposure to traumatic stressors (4–8 traumatic event types; <i>high trauma-exposed non-PTSD</i>; <i>n</i> = 15), and in PTSD patients (<i>n</i> = 42). Means and SEM are shown. * <i>p</i><0.05, ** <i>p</i><0.01, *** <i>p</i><0.001.</p

Glucocorticoid receptor isoform expression.

<p>Expression levels of glucocorticoid receptor (GR) α and β isoforms as well as GRα/GRβ ratio in the peripheral blood of non-PTSD subjects (<i>n</i> = 35) and PTSD patients (<i>n</i> = 42) measured by real-time quantitative PCR. Means and SEM are shown. ** <i>p</i> = 0.01.</p

Blood cell parameters and plasma cortisol concentration.

<p>Data are presented as mean ± SD.</p

Sociodemographic and clinical characteristics.

a<p>Data are presented as mean ± SD. Group differences were analyzed using chi-square tests (categorical data) and <i>t</i>-tests (continuous data). CAPS, Clinician Administered PTSD Scale; HAM-D, Hamilton Depression Rating Scale; SOMS-7, Screening for Somatoform Symptoms-7.</p

Placebo Effects on the Immune Response in Humans: The Role of Learning and Expectation

<div><p>Placebo responses are primarily mediated via two neuropsychological mechanisms: patients’ expectation towards the benefit of a treatment and associative learning processes. Immune functions, like other physiological responses, can be modulated through behavioral conditioning. However, it is unknown whether learned immune responses are affected by the number of re-expositions to the conditioned stimulus (CS) during evocation. Moreover, it is unclear whether immune functions can also be modulated through mere verbally induced expectation. In the experiments reported here, we investigated in healthy male volunteers with an established model of learned immunosuppression whether a single re-exposition to the CS is able to induce a behaviorally conditioned immunosuppression. This conditioned immunosuppression is reflected through a significantly decreased interleukin (IL)-2 production by anti-CD3 stimulated peripheral blood mononuclear cells. Our data revealed that in contrast to four CS re-expositions (control group n = 15; experimental group n = 17), a single CS re-exposition was not sufficient to significantly suppress IL-2 production (control group n = 9, experimental group n = 10). Furthermore, we could demonstrate that mere expectation of taking an immunosuppressant did not cause an immunosuppressive response (n = 8–9 per expectation condition). Together, these findings extend our knowledge about the kinetics and mechanisms of placebo-induced immunosuppression and provide therewith information for designing conditioning protocols, which might be employed as a supportive therapy in clinical settings.</p> </div

Experimental design.

<p>(A) During the acquisition phase in conditioning <i>experiment A</i>, subjects of the experimental group received four times cyclosporin A (CsA) as an US together with a green-colored, novel tasting drink, the CS. During evocation, subjects were re-exposed to the drink four times but received identically looking placebo capsules instead of CsA. The control group was treated in an identical way but received placebo capsules throughout the study. Blood was drawn on the first day (baseline), on day 3 to determine the CsA-effect, on day 8 to analyze possible residual drug effects and on day 10 in order to determine the conditioned effect on IL-2 production <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049477#pone.0049477-Wirth1" target="_blank">[19]</a>. (B) During the acquisition phase in conditioning <i>experiment B</i> subjects were identically treated as in <i>experiment A</i>. However, during evocation, subjects were re-exposed to the drink and the placebo capsules only once. Blood was drawn on the first day (baseline), on day 3 to determine the CsA-effect, on day 8 to analyze possible residual drug effects and on day 10 in order to determine the conditioned effect on IL-2 production. (C) In <i>experiment C</i>, subjects were told to have a probability of either 25%, 50%, 75% or 100% of receiving CsA to manipulate subjects’ expectation of receiving an active drug. Capsules were given at four time points on 3 consecutive days. Blood was drawn on the first day for baseline measurement and on day 3 to determine the potential effect of expectation on IL-2 production of anti-CD3 stimulated PBMC.</p

Catechol-O-Methyltransferase Val158Met Polymorphism Is Associated with Somatosensory Amplification and Nocebo Responses

<div><p>A large number of unwanted adverse events and symptoms reported by patients in clinical trials are not caused by the drug provided, since most of adverse events also occur in corresponding placebo groups. These nocebo effects also play a major role in drug discontinuation in clinical practice, negatively affecting treatment efficacy as well as patient adherence and compliance. Experimental and clinical data document a large interindividual variability in nocebo responses, however, data on psychological, biological or genetic predictors of nocebo responses are lacking. Thus, with an established paradigm of behaviorally conditioned immunosuppressive effects we analyzed possible genetic predictors for nocebo responses. We focused on the genetic polymorphisms in the catechol-O-methyltransferase (<i>COMT</i>) gene (Val158Met) and analyzed drug specific and general side effects before and after immunosuppressive medication and subsequent placebo intake in 62 healthy male subjects. Significantly more drug-specific as well as general side effects were reported from homozygous carriers of the Val158 variant during medication as well as placebo treatment compared to the other genotype groups. Val158/Val158 carriers also had significantly higher scores in the somatosensory amplification scale (SSAS) and the BMQ (beliefs about medicine questionnaire). Together these data demonstrate potential genetic and psychological variables predicting nocebo responses after drug and placebo intake, which might be utilized to minimize nocebo effects in clinical trials and medical practice.</p></div

Expectation induced cytokine response.

<p>(A) Expectation did not induce a significant reduction in IL-2 production in any of the four expectation groups differing in the probability of receiving CsA. IL-2 (pg/ml) concentration in supernatants of anti-CD3 stimulated PBMC was analyzed before and after placebo pill intake (25% n = 9, 50% n = 8, 75% n = 8, 100% n = 8). Data are shown as mean ± SEM. (B) Expectation did not reduce the percentage of IL-2 producing CD4⁺T cells. IL-2 producing CD4⁺T cells were analyzed as percent of total CD4⁺T cells before and after placebo pill intake. Data are shown as mean ± SEM.</p

Reported CsA-specific side effects after <i>Medication</i> (A) and “<i>Placebo</i>” intake, respectively (B).

<p>Significantly higher CsA-specific side effects, after four medication intakes, were reported by homozygous Val158/Val158 carriers (<b>A</b>). This difference was even more pronounced after fourteen “<i>Placebo</i>” intakes (<b>B</b>). Bars represent mean ±SEM. In case of significant F tests, these were followed by Bonferroni post hoc tests; *<i>p</i><0.05, **<i>p</i><0.001.</p

Behavioral conditioning induced cytokine response.

<p>Behaviorally conditioned suppression of IL-2 release was observed after four CS re-expositions (control group n = 15, experimental group n = 17) (Fig. 2A). In contrast, a single CS re-exposition did not induce a significant inhibition in IL-2 production (control group n = 9, experimental group n = 10) (Fig. 2B). Data are expressed as percental changes from baseline. Bars represent mean ± SEM; ** <i>p</i><0.01, *** <i>p</i><0.001.</p