background and aim: probing is the only reliable method for diagnosing periodontal diseases; however, it is a painful examination. the purpose of this study was evaluation of the effect of emla anesthetic gel on the level of pain upon probing in patients with chronic periodontitis referring to the periodontology department of the dental branch of islamic azad university of tehran during 2013-20...

BACKGROUND The total effect of a medication is the sum of its drug effect, placebo effect (meaning response), and their possible interaction. Current interpretation of clinical trials' results assumes no interaction. Demonstrating such an interaction has been difficult due to lack of an appropriate study design. METHODS 180 adults were randomized to caffeine (300 mg) or placebo groups. Each g...

Motivational factors receive little attention in current theories of the placebo effect. Reasons for this position are reviewed, and an argument is made for reconsidering the influence of motivation on the placebo effect. The authors hypothesize that nonconscious goals alter reactions to a placebo expectation. Specifically, the authors predict that the placebo effect is most likely to occur whe...

BACKGROUND The placebo effect in relieving negative emotion arousal is poorly understood. AIMS We examined whether placebo expectation established with noise stimuli could have a transferable anxiolytic effect on negative emotion arousal. METHODS In Experiment 1, noise intensity was surreptitiously lowered during placebo condition in the preconditioning phase to reinforce placebo expectatio...

Almost from the inception of psychotherapy scientists and philosophers have queried both its effectiveness and its mechanisms of action. Today the long-term effectiveness of psychotherapy in treating a diverse range of mental disorders is not in question. However, questions still persist over how different psychotherapy modalities achieve their impressive outcomes, and there has been a sporadic...

BACKGROUND Conventional randomized placebo-controlled study design assumes the absence of drug*placebo interaction. We hypothesized the presence of such an interaction and that conventionally estimated drug effect might be biased. The objectives of the study were to determine the drug*placebo interaction effect (main) and compare conventionally estimated and interaction model-estimated drug eff...

objective: glutamate is considered a target for treating obsessive-compulsive disorder (ocd). the efficacy and safety of the nutritional supplement of n-acetylcysteine (nac) as an adjuvant to serotonin reuptake inhibitor (ssri) for treating children and adolescents with ocd has never been examined. methods: this was a 10-week randomized double-blind placebo-controlled clinical trial with 34 ocd...

In alternative medicine, the main question regarding placebo has been whether a given therapy has more than a placebo effect. Just as mainstream medicine ignores the clinical significance of its own placebo effect, the placebo effect of unconventional medicine is disregarded except for polemics. This essay looks at the placebo effect of alternative medicine as a distinct entity. This is done by...