Irving Kirsch

Publications of Irving Kirsch

• Kirsch et al.'s (2008) calculations are correct: reconsidering Fountoulakis & Möller's re-analysis of the Kirsch data.

  Authors: Tania B Huedo-Medina, Blair T Johnson, Irving Kirsch

  The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP). 03/2012;

• Suggested visual hallucination without hypnosis enhances activity in visual areas of the brain.

  Authors: William J McGeown, Annalena Venneri, Irving Kirsch, Luca Nocetti, Kathrine Roberts, Lisa Foan, Giuliana Mazzoni

  Consciousness and cognition. 11/2011; 21(1):100-16.

  This functional Magnetic Resonance Imaging (fMRI) study investigated high and low suggestible people responding to two visual hallucination suggestions with and without a hypnotic induction.This functional Magnetic Resonance Imaging (fMRI) study investigated high and low suggestible people responding to two visual hallucination suggestions with and without a hypnotic induction. Participants in the study were asked to see color while looking at a grey image, and to see shades of grey while looking at a color image. High suggestible participants reported successful alterations in color perception in both tasks, both in and out of hypnosis, and showed a small benefit if hypnosis was induced. Low suggestible people could not perform the tasks successfully with or without the hypnotic induction. The fMRI results supported the self report data, and changes in brain activity were found in a number of visual areas. The results indicate that a hypnotic induction, although having the potential to enhance the ability of high suggestible people, is not necessary for the effective alteration of color perception by suggestion.

• The altered state issue: dead or alive?

  Authors: Irving Kirsch

  The International journal of clinical and experimental hypnosis. 07/2011; 59(3):350-62.

  Theoretical positions on the altered-state issue are viewed on a continuum rather than a dichotomy. While differences between some pairs of positions have little or no substantive interest, othersTheoretical positions on the altered-state issue are viewed on a continuum rather than a dichotomy. While differences between some pairs of positions have little or no substantive interest, others are important to understanding the nature of hypnotic phenomena. Recent brain imaging data from the University of Hull are reviewed with respect to their implications concerning the existence and functional significance of the hypothesized hypnotic state.

• Suggestibility and suggestive modulation of the Stroop effect.

  Authors: Irving Kirsch

  Consciousness and cognition. 06/2011; 20(2):335-6.

  Although the induction of a hypnotic state does not seem necessary for suggestive modulation of the Stroop effect, this important phenomenon has seemed to be dependent on the subject's level ofAlthough the induction of a hypnotic state does not seem necessary for suggestive modulation of the Stroop effect, this important phenomenon has seemed to be dependent on the subject's level of hypnotic suggestibility. Raz and Campbell's (2011) study indicates that suggestion can modulate the Stroop effect substantially in very low suggestible subjects, as well as in those who are highly suggestible. This finding casts doubt on the presumed mechanism by which suggestive modulation is brought about. Research aimed at uncovering the means by which low suggestible individuals are able to modulate the Stroop effect would be welcome, as would assessment of this effect in moderately suggestible people.

• Review: benefits of antidepressants over placebo limited except in very severe depression.

  Authors: Irving Kirsch

  Evidence-based mental health. 05/2010; 13(2):49.

• The effects of observation and gender on psychogenic symptoms.

  Authors: Giuliana Mazzoni, Lisa Foan, Michael E Hyland, Irving Kirsch

  Health psychology : official journal of the Division of Health Psychology, American Psychological Association. 03/2010; 29(2):181-5.

  To assess the effects of modeling and its interaction with gender in the production of psychogenic symptoms. Healthy volunteers were asked to inhale an inert substance described as a suspectedTo assess the effects of modeling and its interaction with gender in the production of psychogenic symptoms. Healthy volunteers were asked to inhale an inert substance described as a suspected environmental toxin that had been reported to provoke 4 physical symptoms. Subsequently, half of the participants observed a confederate inhale and display the 4 expected symptoms. To control for the general tendency of women to report more physical symptoms than men, participants were also asked to rate the presence of 4 unexpected symptoms. Symptom ratings at 10-min intervals over a 1-hr period. With unexpected symptoms controlled, observation of symptom displays increased reports of expected symptoms significantly. In addition, the presence of another person of the same gender as the participant increased the production of expected symptoms, even when symptoms were not modeled by the confederate. There was also a trend for women to show more expected symptoms than men. Although the effect of modeling was independent of gender, the mere presence of a same-gender individual, as opposed to a person of the opposite gender, increased reports of expected symptoms, regardless of whether the second person (i.e., the confederate) displayed symptoms.

• Hypnotic induction decreases anterior default mode activity.

  Authors: William J McGeown, Giuliana Mazzoni, Annalena Venneri, Irving Kirsch

  Consciousness and cognition. 09/2009;

  The 'default mode' network refers to cortical areas that are active in the absence of goal-directed activity. In previous studies, decreased activity in the 'default mode' has always been associatedThe 'default mode' network refers to cortical areas that are active in the absence of goal-directed activity. In previous studies, decreased activity in the 'default mode' has always been associated with increased activation in task-relevant areas. We show that the induction of hypnosis can reduce anterior default mode activity during rest without increasing activity in other cortical regions. We assessed brain activation patterns of high and low suggestible people while resting in the fMRI scanner and while engaged in visual tasks, in and out of hypnosis. High suggestible participants in hypnosis showed decreased brain activity in the anterior parts of the default mode circuit. In low suggestible people, hypnotic induction produced no detectable changes in these regions, but instead deactivated areas involved in alertness. The findings indicate that hypnotic induction creates a distinctive and unique pattern of brain activation in highly suggestible subjects.

• Suggested visual hallucinations in and out of hypnosis.

  Authors: Giuliana Mazzoni, Elisabetta Rotriquenz, Claudia Carvalho, Manila Vannucci, Kathrine Roberts, Irving Kirsch

  Consciousness and cognition. 04/2009;

  We administered suggestions to see a gray-scale pattern as colored and a colored pattern in shades of gray to 30 high suggestible and eight low suggestible students. The suggestions were administeredWe administered suggestions to see a gray-scale pattern as colored and a colored pattern in shades of gray to 30 high suggestible and eight low suggestible students. The suggestions were administered twice, once following the induction of hypnosis and once without an induction. Besides rating the degree of color they saw in the stimuli differently, participants also rated their states of consciousness as normal, relaxed, hypnotized, or deeply hypnotized. Reports of being hypnotized were limited to highly suggestible participants and only after the hypnotic induction had been administered. Reports of altered color perception were also limited to high suggestibles, but were roughly comparable regardless of whether hypnosis had been induced. These data indicate that suggestible individuals do not slip into a hypnotic state when given imaginative suggestions without the induction of hypnosis, but nevertheless report experiencing difficult suggestions for profound perceptual alterations that are pheonomenologically similar to what they report in hypnosis.

• John f. Chaves (1941-2008).

  Authors: Steven Jay Lynn, Irving Kirsch

  The American psychologist. 02/2009; 64(1):50.

  John F. Chaves is best known for championing a scientific approach to hypnosis. Through his 75 publications, he also made important contributions to the psychological treatment of pain, education inJohn F. Chaves is best known for championing a scientific approach to hypnosis. Through his 75 publications, he also made important contributions to the psychological treatment of pain, education in dentistry, and psychological aspects of illness. Sadly, John died in his home, in Tucson, Arizona, on February 2, 2008, after a two-year battle with stomach cancer. He was 66 years old. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

• "Don't know" responding to answerable and unanswerable questions during misleading and hypnotic interviews.

  Authors: Alan Scoboria, Giuliana Mazzoni, Irving Kirsch

  Journal of experimental psychology. Applied. 10/2008; 14(3):255-65.

  "Don't know" (DK) responses to interview questions are conceptually heterogeneous, and may represent uncertainty or clear statements about the contents of memory. A study examined the subjective"Don't know" (DK) responses to interview questions are conceptually heterogeneous, and may represent uncertainty or clear statements about the contents of memory. A study examined the subjective intent of DK responses in relation to the objective status of information queried, in the context of memory distorting procedures. Participants viewed a video and responded to answerable and unanswerable questions phrased in misleading or nonmisleading formats, while hypnotized or not hypnotized. Subjective meanings of DK responses were queried, and a recognition measure assessed the contents of memory. Lower DK and accuracy rates were consistently associated with unanswerable and misleading questions. One-third of DK responses were statements that the information had no not presented. When these were recoded, accuracy estimates for answerable questions decreased and more so for hypnotized participants. These results demonstrate that DK responses convey different types of information, thus accuracy estimates in studies that permit DK responses may be misestimated. Robust risks associated with asking unanswerable questions and asking questions at all were observed. Implications for working with DK responses during interviews are discussed. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

• Portuguese norms for the Waterloo-Stanford Group C (WSGC) scale of hypnotic susceptibility.

  Authors: Claudia Carvalho, Irving Kirsch, Giuliana Mazzoni, Isabel Leal

  The International journal of clinical and experimental hypnosis. 08/2008; 56(3):295-305.

  Portuguese norms for the Waterloo-Stanford Group C (WSGC) scale of hypnotic susceptibility are presented. A Portuguese translation of this scale was given to 625 Portuguese college students. ScorePortuguese norms for the Waterloo-Stanford Group C (WSGC) scale of hypnotic susceptibility are presented. A Portuguese translation of this scale was given to 625 Portuguese college students. Score distribution, item analysis, and reliability of the WSGC are presented and compared to three North American samples. The findings show that normative data from the Portuguese sample are congruent with the reference samples. The only significant difference obtained was a lower proportion of participants scoring within the high range of hypnotic suggestibility on the WSGC.

• Consistency of the placebo effect.

  Authors: Ben Whalley, Michael E Hyland, Irving Kirsch

  Journal of psychosomatic research. 06/2008; 64(5):537-41.

  OBJECTIVE: The existence of reliable personality predictors of the placebo effect is controversial. For prediction to be possible, the response to placebo must be reliable. We tested the consistencyOBJECTIVE: The existence of reliable personality predictors of the placebo effect is controversial. For prediction to be possible, the response to placebo must be reliable. We tested the consistency of the placebo effect by assessing the response to four trials of placebo analgesic treatment. METHODS: Two identical experimental pain stimuli were administered simultaneously to matching fingers on both hands. Pain sensation was compared between one finger, which was treated with a placebo cream and the other which was not treated. Two placebo creams were used, each with a different label. The procedure was repeated between 1 and 8 days later using the same creams and order of presentation. Two personality traits (acquiescence and absorption) and response expectancy were assessed as potential predictors of the placebo effect. RESULTS: Placebo effects across trials were highly correlated (r=.60 and .77) when placebos bore the same name but were not significantly correlated when placebos had different names. Placebo effects were significantly associated with response expectancy but not with acquiescence or absorption. CONCLUSIONS: Context-specific predictions of placebo response (e.g., expectancy) are possible, but personality predictors will not be consistent across contexts.

• The effect of posthypnotic suggestion, hypnotic suggestibility, and goal intentions on adherence to medical instructions.

  Authors: Claudia Carvalho, Giuliana Mazzoni, Irving Kirsch, Maria Meo, Maura Santandrea

  The International journal of clinical and experimental hypnosis. 05/2008; 56(2):143-55.

  The effects of implementation intentions and posthypnotic suggestion were investigated in 2 studies. In Experiment 1, participants with high levels of hypnotic suggestibility were instructed to takeThe effects of implementation intentions and posthypnotic suggestion were investigated in 2 studies. In Experiment 1, participants with high levels of hypnotic suggestibility were instructed to take placebo pills as part of an investigation of how to best enhance compliance with medical instruction. In Experiment 2, participants with high, medium, and low levels of hypnotic suggestibility were asked to run in place, take their pulse rate before, and send an e-mail report to the experimenter each day. Experiment 1 revealed enhanced adherence as a function of both implementation intentions and posthypnotic suggestion. Experiment 2 failed to find any significant main effects but found a significant interaction between suggestibility and the effects of posthypnotic suggestion. Posthypnotic suggestion enhanced adherence among high suggestible participants but lowered it among low suggestibles.

• Moving beyond depression: How full is the glass?

  Authors: Irving Kirsch, Blair T Johnson

  BMJ (Clinical research ed.). 04/2008; 336(7645):629-30.

• Initial severity and antidepressant benefits: a meta-analysis of data submitted to the Food and Drug Administration.

  Authors: Irving Kirsch, Brett J Deacon, Tania B Huedo-Medina, Alan Scoboria, Thomas J Moore, Blair T Johnson

  PLoS medicine. 03/2008; 5(2):e45.

  BACKGROUND: Meta-analyses of antidepressant medications have reported only modest benefits over placebo treatment, and when unpublished trial data are included, the benefit falls below acceptedBACKGROUND: Meta-analyses of antidepressant medications have reported only modest benefits over placebo treatment, and when unpublished trial data are included, the benefit falls below accepted criteria for clinical significance. Yet, the efficacy of the antidepressants may also depend on the severity of initial depression scores. The purpose of this analysis is to establish the relation of baseline severity and antidepressant efficacy using a relevant dataset of published and unpublished clinical trials. METHODS AND FINDINGS: We obtained data on all clinical trials submitted to the US Food and Drug Administration (FDA) for the licensing of the four new-generation antidepressants for which full datasets were available. We then used meta-analytic techniques to assess linear and quadratic effects of initial severity on improvement scores for drug and placebo groups and on drug-placebo difference scores. Drug-placebo differences increased as a function of initial severity, rising from virtually no difference at moderate levels of initial depression to a relatively small difference for patients with very severe depression, reaching conventional criteria for clinical significance only for patients at the upper end of the very severely depressed category. Meta-regression analyses indicated that the relation of baseline severity and improvement was curvilinear in drug groups and showed a strong, negative linear component in placebo groups. CONCLUSIONS: Drug-placebo differences in antidepressant efficacy increase as a function of baseline severity, but are relatively small even for severely depressed patients. The relationship between initial severity and antidepressant efficacy is attributable to decreased responsiveness to placebo among very severely depressed patients, rather than to increased responsiveness to medication.

• Clinical trials and the response rate illusion.

  Authors: Irving Kirsch, Joanna Moncrieff

  Contemporary clinical trials. 08/2007; 28(4):348-51.

  Clinical trial outcome data can be presented and analyzed as mean change scores or as response rates. These two methods of presenting the data can lead to divergent conclusions. This article exploresClinical trial outcome data can be presented and analyzed as mean change scores or as response rates. These two methods of presenting the data can lead to divergent conclusions. This article explores the reasons for the apparently divergent outcomes produced by these methods and considers their implications for the analysis and reportage of clinical trial data. It is shown that relatively small differences in improvement scores can produce relatively large differences in expected response rates. This is because differences in response rates do not indicate differences in the number of people who have improved; they indicate differences in the number of people whose degree of improvement has pushed them over a specified criterion. Therefore, patients classified as non-responders may have shown substantial and clinically significant improvement, and these are the patients who are most likely to become responders when given medication. Response rates based on continuous data do not add information, and they can create an illusion of clinical effectiveness.

• Hypnotic history: a reply to critics.

  Authors: Irving Kirsch, Giuliana Mazzoni, Guy H Montgomery

  The American journal of clinical hypnosis. 05/2007; 49(4):249-54.

  This article responds to comments on Kirsch, Mazzoni, & Montgomery (2007). Contrary to the perceptions of some commentators, the target article was not aimed at supporting a particular view ofThis article responds to comments on Kirsch, Mazzoni, & Montgomery (2007). Contrary to the perceptions of some commentators, the target article was not aimed at supporting a particular view of hypnosis. Instead, it was a reminder of a long accepted axiom in hypnosis research: the effects of hypnotic suggestions cannot be attributed to hypnosis unless it is demonstrated that the same suggestion does not produce the effect outside of hypnosis.

• Illness by suggestion: expectancy, modeling, and gender in the production of psychosomatic symptoms.

  Authors: William Lorber, Giuliana Mazzoni, Irving Kirsch

  Annals of behavioral medicine : a publication of the Society of Behavioral Medicine. 03/2007; 33(1):112-6.

  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 theBACKGROUND: 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 randomly 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.

• Remembrance of hypnosis past.

  Authors: Irving Kirsch, Giuliana Mazzoni, Guy H Montgomery

  The American journal of clinical hypnosis. 02/2007; 49(3):171-8; discussion 179-80, 183-4.

  The history of the most enduring experimental design in hypnosis research is reviewed. More than 75 years of research converge to indicate that: (1) all of the phenomena produced in hypnosis byThe history of the most enduring experimental design in hypnosis research is reviewed. More than 75 years of research converge to indicate that: (1) all of the phenomena produced in hypnosis by suggestion also can be produced by suggestion without the induction of hypnosis, (2) the induction of hypnosis produces a relatively small increase in responsiveness to suggestion, and (3) hypnotic and waking suggestion are highly correlated, in many cases rivalling the reliability of the suggestibility measure. The importance of these data to both clinical and experimental hypnosis is emphasized.

• Effects of misleading questions and hypnotic memory suggestion on memory reports: a signal-detection analysis.

  Authors: Alan Scoboria, Giuliana Mazzoni, Irving Kirsch

  The International journal of clinical and experimental hypnosis. 08/2006; 54(3):340-59.

  In 2002, the first author and colleagues reported data indicating that both hypnosis and misleading questions decreased the accuracy of memory reports and decreased "don't know" response rates, thatIn 2002, the first author and colleagues reported data indicating that both hypnosis and misleading questions decreased the accuracy of memory reports and decreased "don't know" response rates, that the effects of misleading questions were significantly greater than those of hypnosis, and that the two effects were additive. Using a sample of 194 undergraduate students, the present study replicated the findings that misleading questions reduce accuracy and "don't know" responding but failed to replicate the negative effect of hypnosis on memory reports. Signal detection analysis indicated that misleading questioning produced decreased sensitivity accompanied by higher response bias, though affecting sensitivity more than producing a criterion shift.