***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: Experimental challenge studies may generate and test hypotheses regarding the pathophysiology of panic disorder and may serve to identify pathophysiologically relevant subtypes . It has been suggested that gender-related differences may be relevant in the development and maintenance of panic disorder . In a r and omized double blind design the effects of placebo and sodium lactate administration in 14 female and 16 male patients with panic disorder and 23 healthy control subjects were compared using the Acute Panic Inventory ( API ) score and derived formal criteria for a panic attack . Panic attack frequency following sodium lactate was 76.6 % in the patient group . Although control subjects had a lactate-induced increase in the API score as well , this effect was much weaker . No panic attacks occurred in patients with panic disorder or healthy control subjects receiving a placebo . However , a gender effect was observed in the putative panicogenic placebo condition : female patients with panic disorder had more subthreshold panic anxiety as measured with the API score . The data give evidence for an increased nocebo response in female patients with panic disorder Nocebo hyperalgesia has received sparse experimental attention compared to placebo analgesia . The aim of the present study was to investigate if personality traits and fear of pain could predict experimental nocebo hyperalgesia . One hundred and eleven healthy volunteers ( 76 females ) participated in an experimental study in which personality traits and fear of pain were measured prior to induction of thermal heat pain . Personality traits were measured by the Big-Five Inventory-10 . Fear of pain was measured by the Fear of Pain Question naire III . Heat pain was induced by a PC-controlled thermode . Pain  was measured by a computerized visual analog scale .  Stress levels during the experiment were measured by numerical rating scales . The participants were r and omized to a Nocebo group or to a no-treatment Natural History group . The results revealed that pain and stress levels were significantly higher in the Nocebo group after nocebo treatment . Mediation analysis showed that higher levels of the Fear of Pain Question naire III factor “ fear of medical pain ” significantly increased stress levels after nocebo treatment and that higher stress levels were associated with increased nocebo hyperalgesic responses . There were no significant associations between any of the personality factors and the nocebo hyperalgesic effect . The results from the present study suggest that dispositional fear of pain might be a useful predictor for nocebo hyperalgesia and emotional states concomitant with expectations of increased pain . Furthermore , measurement of traits that are specific to pain experience is probably better suited for prediction of nocebo hyperalgesic responses compared to broad measures of personality OBJECTIVE This study investigated the impact of the social modeling of side effects following placebo medication ingestion on the nocebo and placebo effect . It also investigated whether medication br and ing ( br and or generic labeling ) moderated social modeling effects . METHOD Eighty-two university students took part in the study which was purportedly investigating the impact of fast-acting beta-blocker medications ( actually placebos ) on preexamination anxiety . After taking the medication , participants were r and omized to either witness a female confederate report experiencing side effects or no side effects after taking the same medication . Differences in symptom reporting , blood pressure , heart rate , and anxiety were assessed between the social modeling of side effects and no modeling groups . RESULTS Seeing a female confederate report side effects reduced the placebo effect in systolic ( p = .009 ) and diastolic blood pressure ( p = .033 ) . Seeing a female confederate report side effects also increased both total reported symptoms ( mean [ SE ] 7.35 [ .54 ] vs. 5.16 [ 0.53 ] p = .005 ) and symptoms attributed to the medication ( 5.27 [ 0.60 ] vs. 3.04 [ 0.59 ] p = .01 ) , although the effect on symptoms was only seen in female participants . Females who saw the confederate report side effects reported approximately twice the number of symptoms as those in the no modeling group . Social modeling did not affect heart rate or anxiety . Medication br and ing did not influence placebo or nocebo outcomes . CONCLUSIONS The social modeling of symptoms can substantially reduce or eliminate the placebo effect . Viewing a female confederate display symptoms after taking the same medication increases symptom reporting in females UNLABELLED Expectations and beliefs shape the experience of pain . This is most evident in context -induced , placebo analgesia , which has recently been shown to interact with the trait of magical thinking ( MT ) in adults . In children , placebo analgesia and the possible roles that MT and gender might play as modulators of placebo analgesia have remained unexplored . Using a paradigm in which heat pain stimuli were applied to both forearms , we investigated whether MT and gender can influence the magnitude of placebo analgesia in children . Participants were 49 right-h and ed children ( aged 6 - 9 years ) who were r and omly assigned-stratified for MT and gender-to either an analgesia-expectation or a control-expectation condition . For both conditions , the placebo was a blue-colored h and disinfectant that was applied to the children 's forearms . Independent of MT , the placebo treatment significantly increased both heat pain threshold and tolerance . The threshold placebo effect was more pronounced for girls than boys . In addition , independent of the expectation treatment , low-MT boys showed a lower tolerance increase on the left compared to the right side . Finally , MT specifically modulated tolerance on the right forearm side : Low-MT boys showed an increase , whereas high-MT boys showed a decrease in heat pain tolerance . This study documented a substantial expectation-induced placebo analgesia response in children ( girls > boys ) and demonstrated MT and gender-dependent laterality effects in pain perception . The findings may help improve individualized pain management for children . PERSPECTIVE The study documents the first experimental evidence for a substantial expectancy-induced placebo analgesia response in healthy children aged 6 to 9 years ( girls > boys ) . Moreover , the effect was substantially higher than the placebo response typically found in adults . The findings may help improve individualized pain management for children Background : Expectancy and modeling have been cited as factors in mass psychogenic illness ( MPI ) , which reportedly affects more women than men . Purpose : The purpose of the study is to assess the effects of expectancy and modeling in a controlled laboratory analogue of MPI . Methods : Students were r and omly assigned to inhale or not inhale an inert placebo described as a suspected environmental toxin that had been linked to four symptoms typical of reported instances of MPI . Half of the students observed a female confederate inhale the substance and subsequently display the specified symptoms . Results : Students who inhaled the placebo reported greater increases in symptoms , and the increase was significantly greater for the specified symptoms than for other symptoms . Observation of the confederate displaying symptoms increased specified symptoms significantly among women but not among men . Changes in reported symptoms were significantly associated with changes in unobtrusively observed behavior . Conclusions : Symptoms typical of clinical reports of MPI can be induced by manipulating response expectancies , and the effects are specific rather than generalized . Among women , this effect is enhanced by observing another participant ( who in this study is also female ) display symptoms . This suggests that the preponderance of women showing symptoms in outbreaks of MPI may be due to gender-linked differences in the effects of modeling on psychogenic symptoms We conjectured that individual differences in tension-reduction alcohol outcome expectancies ( TR-AOEs ) could produce widely varying responses to manipulations in alcohol-placebo studies and tested this idea by having individuals with social phobia give speeches in front of a group . One speech occurred before and one after participants consumed either a placebo beverage or a control beverage ( i.e. , a nonalcoholic drink described as containing no alcohol ) . Study results indicate that the placebo manipulation reduced cognitive and affective symptoms of anxiety to a greater extent for males with high TR-AOEs than for males with low TR-AOEs . This pattern was not found for women in the placebo group or for individuals in the control group . These findings demonstrate a moderating effect of TR-AOEs on the association between the consumption of a  placebo beverage and response to an anxiety challenge and highlight the importance of accounting for gender and outcome expectancies when evaluating psychoactive substances Rationale In a r and omised placebo-controlled clinical trial it is assumed that psychosocial effects of the treatment , regression to the mean and spontaneous remission are identical in the drug and placebo group . Consequently , any difference between the groups can be ascribed to the pharmacological effects . Previous studies suggest that side effects of drugs can enhance expectancies of treatment effects in the drug group compared to the placebo group , and thereby increase placebo responses in the drug group compared to the placebo group . Objectives The hypothesis that side effects of drugs can enhance expectancies and placebo responses was tested . Method Painful laser stimuli were delivered to 20 healthy subjects before and after administration of a drink with 0 or 4 mg/kg caffeine . The drink was administered either with information that it contained a painkiller or that it was a placebo .  Laser-evoked potentials and reports of pain , expectancy , arousal and stress were measured . Results Four milligrammes per kilogramme of caffeine reduced pain . Information that a painkiller was administered increased the analgesic effect of caffeine compared to caffeine administered with no drug information . This effect was mediated by expectancies . Information and expectancies had no effect on pain intensity when 0 mg/kg was administered . Conclusion The analgesic effect of caffeine was increased by information that a painkiller was administered . This was due to an interaction of the pharmacological action of the drug and expectancies . Hence , psychosocial effects accompanying a treatment can differ when an active drug is administered compared to a placebo The nocebo effect is the onset of untoward reactions following the administration of an indifferent substance . The oral challenge with alternative drugs plays a central role in the management of drug allergy and the use of inert substances is part of this procedure . We evaluated the occurrence and clinical characteristics of nocebo effect in patients with adverse drug reactions . Six hundred patients , seen in three different centres ( Genoa , Naples and Verona ) with a history of reactions to drugs , underwent a blind oral challenge with the administration of an indifferent substance and active drugs . The administration of an inert substance provoked untoward reactions in 54 patients ( 27 % ) in Verona , 60 ( 30 % ) in Naples and 48 ( 24 % ) in Genoa . The overall occurrence of nocebo effect was 27 % . The majority of reactions were subjective symptoms ( itching , malaise , headache etc ) , perceived as troublesome by all subjects . The occurrence was significantly higher in women than in men . Our data , collected in a large population , confirm that the nocebo effect occurs frequently in clinical practice . In managing adverse drug reactions through oral challenge the nocebo effect is m and atory to recognize false positive responses BACKGROUND Social cues and interpersonal interactions strongly contribute to evoke placebo effects that are pervasive in medicine and depend upon the activation of endogenous modulatory systems . Here , we explore the possibility to boost placebo effects by targeting pharmacologically the vasopressin system , characterized by a sexually dimorphic response and involved in the regulation of human and nonhuman social behaviors . METHODS We enrolled 109 healthy participants and studied the effects of intranasal administration of an arginine vasopressin 1A and 1B receptor agonist against 1 ) no treatment , 2 ) oxytocin , and 3 ) saline in a r and omized , placebo-controlled , double-blind , parallel design trial using a well-established model of placebo analgesia while controlling for sex differences . RESULTS Vasopressin agonists boosted placebo effects in women but had no effect in men . The effects of vasopressin on expectancy-induced analgesia were significantly larger than those observed in the no-treatment ( p < .004 ) , oxytocin ( p < .001 ) , and saline ( p < .015 ) groups . Moreover , women with lower dispositional anxiety and cortisol levels showed the largest vasopressin-induced modulation of placebo effects , suggesting a moderating interplay between pre-existing psychological factors and treatment cortisol changes . CONCLUSIONS This is the first study that demonstrates that arginine vasopressin boosts placebo effects and that the effect of vasopressin depends upon a significant sex by treatment interaction . These findings are novel and might open up new avenues for clinical ly relevant research due to the therapeutic potentials of vasopressin as well as the possibility to systematic ally control for influences of placebo responses in clinical trials We investigated the mechanisms underlying the activation of endogenous opioids in placebo analgesia by using the model of human experimental ischemic arm pain . Different types of placebo analgesic responses were evoked by means of cognitive expectation cues , drug conditioning , or a combination of both . Drug conditioning was performed by means of either the opioid agonist morphine hydrochloride or the nonopioid ketorolac tromethamine . Expectation cues produced placebo responses that were completely blocked by the opioid antagonist naloxone . Expectation cues together with morphine conditioning produced placebo responses that were completely antagonized by naloxone . Morphine conditioning alone ( without expectation cues ) induced a naloxone-reversible placebo effect . By contrast , ketorolac conditioning together with expectation cues elicited a placebo effect that was blocked by naloxone only partially . Ketorolac conditioning alone produced placebo responses that were naloxone-insensitive . Therefore , we evoked different types of placebo responses that were either naloxone-reversible or partially naloxone-reversible or , otherwise , naloxone-insensitive , depending on the procedure used to evoke the placebo response . These findings show that cognitive factors and conditioning are balanced in different ways in placebo analgesia , and this balance is crucial for the activation 
    Output:
    
This review indicates that there are sex differences in the placebo and nocebo effects , probably caused by sex differences in stress , anxiety , and the endogenous opioid system