Another meta-analysis found that 79% of depressed patients receiving placebo remained well (for 12 weeks after an initial 6–8 weeks of successful therapy) compared to 93% of those receiving antidepressants. In the continuation phase however, patients on placebo relapsed significantly more often than patients on antidepressants.[125] A 2009 meta-analysis reported that in 2005 68% of the effects of antidepressants was due to the placebo effect, which was more than double the placebo response rate in 1980.[126]
While some say that blanket consent, or the general consent to unspecified treatment given by patients beforehand, is ethical, others argue that patients should always obtain specific information about the name of the drug they are receiving, its side effects, and other treatment options.[127] Even though some patients do not want to be informed, health professionals are ethically bound to give proper information about the treatment given. There is such a debate over the use of placebos because while placebos are used for the good of many to test the effectiveness of drugs, some argue that it is unethical to ever deprive individual patients of effective drugs.[128]
Chronic fatigue syndrome[edit]
It was previously assumed that placebo response rates in patients with chronic fatigue syndrome (CFS) are unusually high, "at least 30% to 50%," because of the subjective reporting of symptoms and the fluctuating nature of the condition. According to a meta-analysis and contrary to conventional wisdom, the pooled response rate in the placebo group was 19.6%, even lower than in some other medical conditions. The authors offer possible explanations for this result: CFS is widely understood to be difficult to treat, which could reduce expectations of improvement. In context of evidence showing placebos do not have powerful clinical effects when compared to no treatment, a low rate of spontaneous remission in CFS could contribute to reduced improvement rates in the placebo group. Intervention type also contributed to the heterogeneity of the response. Low patient and provider expectations regarding psychological treatment may explain particularly low placebo responses to psychiatric treatments.[129]
List of medical conditions[edit]
The effect of placebo treatments (an inert pill unless otherwise noted) has been studied for the following medical conditions. Many of these citations concern research showing that active treatments are effective, but that placebo effects exist as well.
• Acne[130][131]
• Anxiety disorders[130][131]
• Asthma[132][133]
• Autism: language and behavior problems[134][135]
• Benign prostatic enlargement[136]
• Binge eating disorder[137]
• Bipolar mania[138]
• Burning mouth syndrome[139]
• Cough[19]
• Crohn's disease[140]
• Depression[141][142][143][144]
• Dyspepsia and Stomach motility[145]
• Epilepsy[146]
• Erectile dysfunction[147]