Placebo Effects (placebo + effects)

Distribution by Scientific Domains


Selected Abstracts


Placebo Effects: Understanding the Mechanisms in Health and Disease

FOCUS ON ALTERNATIVE AND COMPLEMENTARY THERAPIES AN EVIDENCE-BASED APPROACH, Issue 4 2009
E Ernst
[source]


Placebo psychotherapy: Synonym or oxymoron?

JOURNAL OF CLINICAL PSYCHOLOGY, Issue 7 2005
Irving Kirsch
Contrary to some recent claims, the placebo effect is real and in some cases very substantial. Placebo effects can be produced or enhanced by classical conditioning, but consistent with virtually all contemporary conditioning theories, these effects are generally mediated by expectancy. Expectancy can also produce placebo effects that are inconsistent with conditioning history. Although expectancy also plays an important role in psychotherapy outcome, the logic of placebo-controlled trials does not map well onto psychotherapy research. The idea of evaluating the efficacy of psychotherapy by controlling for nonspecific or placebo factors is based on a flawed analogy and should be abandoned. © 2005 Wiley Periodicals, Inc. J Clin Psychol 61: 791,803, 2005. [source]


The placebo response complex

THE JOURNAL OF ANALYTICAL PSYCHOLOGY, Issue 5 2004
Richard Kradin
Abstract:, Placebo effects contribute to beneficial therapeutic responses and are common in anxiety and depressive disorders. It is posited that placebo effects are yielded by autonomous feeling-toned complexes capable of re-establishing background self-states of well-being. The relationship between the placebo response complex and modern neurobiological models of self is explored. The psychological roots of the placebo response complex in implicit memories of organized attachment between child and early caretakers and in Sandler's conception of the benign superego are examined. The relationships between the negative placebo (nocebo) response complex, Freud's negative therapeutic reaction, and Fordham's defence of the self are explored. Finally, it is suggested that approaches fundamental to the analytic encounter, e.g., mirroring, affectual exchanges, attunement, and containment are likely to optimize the salutary effects of both psychological and somatic therapeutic interventions. [source]


Placebo psychotherapy: Synonym or oxymoron?

JOURNAL OF CLINICAL PSYCHOLOGY, Issue 7 2005
Irving Kirsch
Contrary to some recent claims, the placebo effect is real and in some cases very substantial. Placebo effects can be produced or enhanced by classical conditioning, but consistent with virtually all contemporary conditioning theories, these effects are generally mediated by expectancy. Expectancy can also produce placebo effects that are inconsistent with conditioning history. Although expectancy also plays an important role in psychotherapy outcome, the logic of placebo-controlled trials does not map well onto psychotherapy research. The idea of evaluating the efficacy of psychotherapy by controlling for nonspecific or placebo factors is based on a flawed analogy and should be abandoned. © 2005 Wiley Periodicals, Inc. J Clin Psychol 61: 791,803, 2005. [source]


A critical evaluation of current views regarding eye movement desensitization and reprocessing (EMDR): Clarifying points of confusion

JOURNAL OF CLINICAL PSYCHOLOGY, Issue 1 2002
Byron R. Perkins
EMDR is an active psychological treatment for PTSD that has received widely divergent reactions from the scientific and professional community. This article examines points of confusion in the published literature on EMDR, including the theoretical, empirical, and historical issues around EMDR and placebo effects, exposure procedures, the eye movement component, treatment fidelity issues, and outcome studies. It also examines historical information relevant to the scientific process and charges of "pseudoscience" regarding EMDR. We conclude that the confusion in the literature is due to (a) the lack of an empirically validated model capable of convincingly explaining the effects of the EMDR method, (b) inaccurate and selective reporting of research, (c) some poorly designed empirical studies, (d) inadequate treatment fidelity in some outcome research, and (e) multiple biased or inaccurate reviews by a relatively small group of authors. Reading the original research articles frequently helps to reduce the confusion arising from the research review literature. © 2002 John Wiley & Sons, Inc. J Clin Psychol 58: 77,97, 2002. [source]


Acupuncture , a critical analysis

JOURNAL OF INTERNAL MEDICINE, Issue 2 2006
E. ERNST
Abstract. Even though widely used in today's clinical practice, acupuncture has remained a controversial subject. Many reviews are currently available but most lack a critical stance and some are overtly promotional. The aim of this overview is to provide a balanced, critical analysis of the existing evidence. Some of the original concepts of traditional acupuncture are not supported by good scientific evidence. Several plausible theories attempt to explain how acupuncture works but none are proved beyond doubt. The clinical effectiveness of acupuncture continues to attract controversy. Many controlled clinical trials and numerous systematic reviews of these studies have been published. Considerable problems are encountered when interpreting these data. Heterogeneity is a significant drawback of both clinical trials and systematic reviews. Some of the controversies may be resolved through the use of the new ,placebo needles' which enable researchers to adequately control for placebo effects of acupuncture. The majority of studies using such devices fails to show effects beyond a placebo response. Acupuncture has been associated with serious adverse events but most large-scale studies suggest that these are probably rare. Nonserious adverse effects occur in 7,11% of all patients. In conclusion, acupuncture remains steeped in controversy. Some findings are encouraging but others suggest that its clinical effects mainly depend on a placebo response. [source]


Cultural Variations in the Placebo Effect: Ulcers, Anxiety, and Blood Pressure

MEDICAL ANTHROPOLOGY QUARTERLY, Issue 1 2000
Daniel E. Moerman
An analysis of the control groups in double-blind trials of medicines demonstrates broad variation,from 0 to 100 percent,in placebo effectiveness rates for the same treatment for the same condition. In two cases considered here, drug healing rates covary with placebo healing rates; placebo healing is the ultimate and inescapable "complementary medicine. " Several factors can account for the dramatic variation in placebo healing rates, including cultural ones. But because variation differs by illness, large placebo effects for one condition do not necessarily anticipate large placebo effects for other conditions as well. Deeper understanding of the intimate relationship between cultural and biological processes will require close ethnographic scrutiny of the meaningfulness of medical treatment in different societies, [placebo effect, ulcer disease, anxiety, hypertension, cross-cultural variation] [source]


Probiotics and health: a review of the evidence

NUTRITION BULLETIN, Issue 4 2009
E. Weichselbaum
Summary Probiotics are live microorganisms , mainly bacteria , which when administered in adequate amounts confer a health benefit on the host. There is rising interest in this area, but reports in the media are often conflicting. The aim of this review is to consider the current evidence on the effects of probiotics on health, focusing on gut-related health issues and the immune system, with the objective to provide a clearer picture of whether and how probiotics can be beneficial for health. The outcomes of this review are based on more than 100 original studies, meta-analyses and systematic reviews. A variety of different strains have been used in studies on probiotics, and it is important to remember that the effectiveness of probiotics is strain-specific, which means that each single probiotic strain has to be tested to assess its potential health benefits. Overall, despite the diversity of strains used in the studies included in this review, there is evidence that probiotics have the potential to be beneficial for our health. Studies in patients with inflammatory bowel disease show probiotic strains to be able to decrease the recurrence of ulcerative colitis and occurrence and recurrence of pouchitis, however, current evidence suggests that probiotics are ineffective in treating patients with Crohn's disease. Patients with irritable bowel syndrome show a reduction in symptoms when treated with selected probiotic strains, but high placebo effects have been reported as well. The evidence of the efficacy of probiotics in patients suffering from constipation is limited, but the evidence seems promising for some strains to bring relief to patients suffering from constipation. There is good evidence that a number of probiotic strains are effective in preventing antibiotic-associated diarrhoea. The most commonly studied strains are Lactobacillus rhamnosus GG (LGG) and Saccharomyces boulardii, but other strains and mixtures of strains seem to be effective as well. There is also promising evidence of a preventive effect of probiotics in Clostridium difficile -associated diarrhoea, although some studies have been too small to obtain statistically significant findings. The effect of probiotics in acute diarrhoea, particularly in children, is well studied. Selected probiotic strains seem to be effective in reducing the duration of acute diarrhoea. LGG and S. boulardii are again the most commonly used strains and a number of studies have shown them to be effective, although one meta-analysis showed that the effect of LGG was only significant in children in Western countries, not in children in developing countries, which may be due to different causes of diarrhoea in these regions. Studies investigating the preventive effect of probiotics in the context of common cold and flu infections show that the studied strains failed to lower the incidence of episodes but that they have the potential to decrease the duration of episodes, which suggests that the immune system may be more efficient in fighting off common cold and flu infections after consuming these strains. The evidence so far does not suggest that probiotics are effective in preventing or treating allergies or in treating eczema. However, some probiotic strains seem to lower the risk of developing eczema if taken by pregnant women and their infants in early life. [source]


The placebo response complex

THE JOURNAL OF ANALYTICAL PSYCHOLOGY, Issue 5 2004
Richard Kradin
Abstract:, Placebo effects contribute to beneficial therapeutic responses and are common in anxiety and depressive disorders. It is posited that placebo effects are yielded by autonomous feeling-toned complexes capable of re-establishing background self-states of well-being. The relationship between the placebo response complex and modern neurobiological models of self is explored. The psychological roots of the placebo response complex in implicit memories of organized attachment between child and early caretakers and in Sandler's conception of the benign superego are examined. The relationships between the negative placebo (nocebo) response complex, Freud's negative therapeutic reaction, and Fordham's defence of the self are explored. Finally, it is suggested that approaches fundamental to the analytic encounter, e.g., mirroring, affectual exchanges, attunement, and containment are likely to optimize the salutary effects of both psychological and somatic therapeutic interventions. [source]