***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Placebo treatment can significantly influence subjective symptoms . However , it is widely believed that response to placebo requires concealment or deception . We tested whether open-label placebo ( non-deceptive and non-concealed administration ) is superior to a no-treatment control with matched patient-provider interactions in the treatment of irritable bowel syndrome ( IBS ) . Methods Two-group , r and omized , controlled three week trial ( August 2009-April 2010 ) conducted at a single academic center , involving 80 primarily female ( 70 % ) patients , mean age 47±18 with IBS diagnosed by Rome III criteria and with a score ≥150 on the IBS Symptom Severity Scale ( IBS-SSS ) . Patients were r and omized to either open-label placebo pills presented as “ placebo pills made of an inert substance , like sugar pills , that have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes ” or no-treatment controls with the same quality of interaction with providers . The primary outcome was IBS Global Improvement Scale ( IBS-GIS ) . Secondary measures were IBS Symptom Severity Scale ( IBS-SSS ) , IBS Adequate Relief ( IBS-AR ) and IBS Quality of Life ( IBS-QoL ) . Findings Open-label placebo produced significantly higher mean ( ±SD ) global improvement scores ( IBS-GIS ) at both 11-day midpoint ( 5.2±1.0 vs. 4.0±1.1 , p<.001 ) and at 21-day endpoint ( 5.0±1.5 vs. 3.9±1.3 , p = .002 ) . Significant results were also observed at both time points for reduced symptom severity ( IBS-SSS , p = .008 and p = .03 ) and adequate relief ( IBS-AR , p = .02 and p = .03 ) ; and a trend favoring open-label placebo was observed for quality of life ( IBS-QoL ) at the 21-day endpoint ( p = .08 ) . Conclusion Placebos administered without deception may be an effective treatment for IBS . Further research is warranted in IBS , and perhaps other conditions , to eluci date whether physicians can benefit patients using placebos consistent with informed consent . Trial Registration Clinical Trials.gov Background Several studies demonstrated that placebo treatment may have a significant impact on many different symptoms . While in the traditional view concealment of the placebo is essential , recent studies report intriguing evidence that placebos may work even without deception . For example , it has been demonstrated that open-label placebos can improve symptoms in allergic rhinitis . However , the mechanisms of how placebos without concealment work remain unknown . Trial design In order to examine expectancy effects we conducted a r and omized controlled trial ( N = 46 ) , in which patients with allergic symptoms received either placebos without deception or no pills at all . In half of those patients we induced positive expectations about the placebo effect . After two weeks we tested whether symptoms and quality of life had changed . Results Results revealed that open-label placebos improved allergic symptoms more than the control group . Inducing positive expectations had no effects on the improvement of allergic symptoms ( the primary and more objective outcome ) , but on mental sum scores of the quality of life question naire . Conclusions Placebos without deception can improve symptoms in allergic rhinitis . Positive expectations do not contribute to the efficacy of open-label placebos , but seem to have an effect on more global and subjective well-being ( mental or emotional quality of life ) . Clinical trial registration number German Clinical Trials Register , Research into placebo effects has convincingly shown that inducing positive outcome expectations can reduce pain and other physical sensations . However , the comparative effects of different expectation inductions , such as verbal suggestion or mental imagery , and their generic effects on physical sensitivity , to different sensations such as pain , itch , and fatigue , are still largely unknown . In the current study , we assessed the individual and combined effects of verbal suggestion and imagery on pain , itch , and fatigue as indicators of physical sensitivity in a r and omized study design . Healthy participants ( n = 116 ) were given an inert ( placebo ) capsule that was said to be effective for reducing physical sensitivity in either the majority ( positive verbal suggestion ) or the minority ( control verbal suggestion ) of users . Subsequently , they imagined either their best possible health ( positive imagery ) or a typical day ( control imagery ) . Sensitivity to pain , itch , and fatigue was tested using a cold pressor test , histamine iontophoresis , and a bicycle test , respectively . Heart rate and skin conductance were recorded continuously . Results showed that positive verbal suggestion and imagery successfully induced positive expectations , but they did not affect physical sensitivity , as indicated by sensitivity to pain , itch , or fatigue , or concurrent physiological responses . These results could indicate that the specificity and concreteness of expectation inductions might be important for their applicability in the treatment of physical symptoms . Trial Registration Nederl and s Trial Register PURPOSE To investigate suggestion-induced placebo effects in inflammatory skin reactions . METHODS A healthy sample of volunteers ( N = 48 ) attended two laboratory sessions . In each , a local short term inflammatory skin reaction was induced with histamine . Participants were told that one session was a control session and the other was a treatment session in which an antihistamine cream would be applied to the arm to reduce the size of the weal and the experience of itch . Inert aqueous cream was applied in both sessions . Participants were r and omly allocated to undergo either the control or the treatment session first . RESULTS The placebo manipulation successfully reduced self-reported itch from the control to the placebo treatment session , but no placebo effect was demonstrated in weal size . Order effects were observed such that only those who underwent control procedures first had a smaller weal in the placebo treatment session as compared to the control session . The same order effect was seen for reported itch at one minute post histamine administration , but this disappeared at the three and five minute measures . CONCLUSION Findings suggest that explicit verbal suggestion can reduce the experience of itch . In addition to conscious awareness , a concrete representation of the suggested changes gained from prior experience to the stimulus may be an important component of placebo effects on inflammatory skin reactions Cutaneous reactivity to challenge with dinitrochlorobenzene ( DNCB ) and diphenylcyclopropenone ( DCP ) was studied in 16 volunteers following hypnotic suggestions to increase and decrease response during sensitization . The immunoreactivity to DNCB and DCP was modulated by direct suggestions and guided imagery under hypnosis .  The volunteers were highly susceptible subjects selected by means of the Harvard Group Scale of Hypnotic Susceptibility . Form A. Measurement of skin reactions to the challenge I month after sensitization was performed double blindly . Results showed a significant ( P<0.01 ) difference in visually scored reactions to DCP and DNCB  between the group instructed to increase reaction to DCP and decrease reaction to DNCB and the group given the opposite instructions . A non‐significant difference ( P= 0.055 ) in skin thickness measured by ultrasound was found between the two groups . The study supports previous reports of experimental modulation of immunoreactivity and indicates that the specific immunnnological processes involved in the development of allergic reactions may be susceptible to psychological factors The therapeutic results of hypnosis with relaxation therapy were evaluated in 15 patients with chronic urticaria of 7.8 years ' average duration . Compared with baseline and control session values , the hypnosis session provided relief of pruritus as measured by three self-report parameters . There was no change in the number of hives . All subjects were given a st and ard test for hypnotizability . Assuming that the results were not biased by their preceding relaxation sessions , we determined that six subjects were hypnotizable and nine were nonhypnotizable . Subjects in both groups improved symptomatically , but hypnotizable subjects had fewer hives and became more symptomatic during the control ( testing and history taking ) session . Hypnotizable subjects also more frequently related stress as a causative factor . At a follow-up examination five to 14 months after the completion of the experimental sessions , six patients were free of hives and an additional seven reported improvement We conducted r and omized clinical trials to examine the impact of direct-to-consumer advertisements on the efficacy of a br and ed drug . We compared the objective ly measured , physiological effect of  Claritin ( Merck & Co. ) , a leading antihistamine medication , across subjects r and omized to watch a movie spliced with advertisements for Claritin or advertisements for Zyrtec ( McNeil ) , a competitor antihistamine . Among subjects who test negative for common allergies , exposure to Claritin advertisements rather than Zyrtec advertisements increases the efficacy of Claritin . We conclude that br and ed drugs can interact with exposure to television advertisements Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Objective : To test the hypothesize that psoriasis patients treated under a partial schedule of pharmacologic ( corticosteroid ) reinforcement  would show less severe symptoms and relapse than those given the same amount of drug under st and ard conditions . Behavioral conditioning as an inherent component of many pharmacotherapeutic protocol s has never been examined . Methods : A double-blind , simple r and omization intervention was conducted with 46 patients from California and New York . Initially , lesions were treated with 0.1 % acetonide triamcinolone under st and ard treatment conditions . Thereafter , a St and ard Therapy group continued on continuous reinforcement ( active drug every treatment ) with 100 % of the initial dose ; Partial Reinforcement patients received a full dose 25 % to 50 % of the time and placebo medication other times ; Dose Control patients received continuous reinforcement with 25 % to 50 % of the initial dose . Results :  Severity of disease scores in California neither supported nor refuted the hypothesis . In New York , where there was no difference between Partial Reinforcement and Dose Control groups at baseline , partial reinforcement effected a greater reduction in lesion severity than Dose Control conditions and did not differ from St and ard Therapy patients receiving two to four times more drug . For the entire population , the frequency of relapse under partial reinforcement ( 26.7 % ) was lower than in Dose Control patients ( 61.5 % ) and did not differ from full-dose treatment ( 22.2 % ) . Conclusions : A partial schedule of pharmacotherapeutic reinforcement could maintain psoriasis patients with a cumulative amount of  corticosteroid  that was relatively ineffective when administered under st and ard treatment conditions . Conceivably , corticosteroid administration only one quarter or half as frequently as currently prescribed is sufficient to treat psoriasis . We posit , however , that these preliminary observations implicate conditioning processes in— and for the design of — regimens of pharmacotherapy . PSS = Psoriasis Severity Scale ; CS = conditioned stimulus ; UCS = unconditioned stimulus To clarify the contribution of stress to classical conditioning-associated asthmatic responses , the effect of fasting stress on conditioned histamine release was investigated in a guinea pig model of asthma . The animals were r and omly divided into 2 groups for Experiment 1 and 2 , and received a conditioning procedure in which ovalbumin ( OA ) as an unconditioned stimulus ( US ) and dimethylsulfide ( DMS , sulfur smelling ) as a conditioned stimulus ( CS ) were simultaneously inhaled after fasting for 16 h. Then , one group was given food as a reward for respiratory distress , and the other group was denied it for more than 3 h , while being placed in front of the feeding group . After this procedure was repeated 5 times , the plasma histamine levels in response to the CS were measured in half of each group in Experiment 1 , and the respiratory resistance ( Rrs ) was assessed similarly in the other half of each group in Experiment 2 . The same experiments were again performed after exchanging assignments of feeding group or fasting group in both experiments . The control groups in both experiments received the CS and the US 10 times separately in a r and om order under 16 h fasting conditions and were provided food after the exposures . After these pseudo-conditioning presentations , the plasma histamine levels or the Rrs in response to the CS were measured . In Experiment 1 , the plasma histamine levels in the fasting stress group after the first conditioning sessions were significantly higher than those of the other groups . This difference was not observed when the groups were exchanged . In Experiment 2 , the fasting stress group showed higher values in the Rrs compared to the other groups , irrespective of the first or second conditionings ; however , they were not significant . The present study indicates that fasting stress after the conditioning procedures exacerbates the following conditioned histamine release , although the stress effect on bronchoconstriction was not confirmed Abstract This r and omized controlled trial was performed to investigate whether placebo effects in chronic low back pain could be harnessed ethically by adding open-label placebo ( OLP ) treatment to treatment as usual ( TAU ) for 3 weeks . Pain severity was assessed on three 0- to 10-point Numeric Rating Scales , scoring maximum pain , minimum pain , and usual pain , and a composite , primary outcome , total pain score . Our other primary outcome was back-related dysfunction , assessed on the Rol and –Morris Disability Question naire . In an exploratory follow-up , participants on TAU received placebo pills for 3 additional weeks . We r and omized 97 adults reporting persistent low back pain for more than 3 months ' duration and diagnosed by a board-certified pain specialist . Eighty-three adults completed the trial . Compared to TAU , OLP elicited greater pain reduction on each of the three 0- to 10-point Numeric Rating Scales and 
    Output:
    
Overall , studies consistently show that placebo and nocebo effects can be induced by various methods ( e.g. , suggestions , conditioning and social cues ) , despite high heterogeneity across studies .
Effects of suggestions were found consistently across subjective and behavioral parameters ( e.g. , itch and scratching in humans ) , whereas conditioning was likely to impact physiological parameters under certain conditions ( e.g. , conditioning of histamine levels in stressed rodents ) .
Brain areas responsible for itch processing were associated with nocebo effects .