Lessons learned from placebo groups in antidepressant trials
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Lessons learned from placebo groups in antidepressant trials. / Shedden Mora, Meike ; Nestoriuc, Yvonne; Rief, Winfried.
In: PHILOS T R SOC B, Vol. 366, No. 1572, 27.06.2011, p. 1879-88.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
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TY - JOUR
T1 - Lessons learned from placebo groups in antidepressant trials
AU - Shedden Mora, Meike
AU - Nestoriuc, Yvonne
AU - Rief, Winfried
PY - 2011/6/27
Y1 - 2011/6/27
N2 - This comprehensive review provides an overview about placebo and nocebo phenomena in antidepressant trials. Improvements in the placebo groups may partly be explained through methodological issues such as natural course of depression and regression to the mean, but also fundamentally reflect investigators' and participants' expectations. A meta-analysis by our group of 96 randomized placebo-controlled trials showed large placebo responses to antidepressant medication. Moderator analyses revealed substantially larger placebo responses in observer ratings compared with self-report. Effect sizes in observer ratings showed strong increase with publication year while this effect was not found for patients' self-ratings. This reflects the strong influence of investigators' expectations. The analysis of 'nocebo effects', e.g. adverse effects in placebo groups of antidepressant trials also confirms the impact of expectations: nocebo symptoms reflected the typical side-effect patterns expected in the drug group, with higher symptoms rates in the placebo groups of tricyclic antidepressant trials compared with placebo groups of trials testing selective serotonin reuptake inhibitors. While the placebo response seems to be similar for women and men, gender differences were found for nocebo rates. In the conclusion, we discuss potential implications for clinical trial designs and argue for interventions aimed at optimizing positive expectations of treatment benefit while minimizing the impact of adverse effects.
AB - This comprehensive review provides an overview about placebo and nocebo phenomena in antidepressant trials. Improvements in the placebo groups may partly be explained through methodological issues such as natural course of depression and regression to the mean, but also fundamentally reflect investigators' and participants' expectations. A meta-analysis by our group of 96 randomized placebo-controlled trials showed large placebo responses to antidepressant medication. Moderator analyses revealed substantially larger placebo responses in observer ratings compared with self-report. Effect sizes in observer ratings showed strong increase with publication year while this effect was not found for patients' self-ratings. This reflects the strong influence of investigators' expectations. The analysis of 'nocebo effects', e.g. adverse effects in placebo groups of antidepressant trials also confirms the impact of expectations: nocebo symptoms reflected the typical side-effect patterns expected in the drug group, with higher symptoms rates in the placebo groups of tricyclic antidepressant trials compared with placebo groups of trials testing selective serotonin reuptake inhibitors. While the placebo response seems to be similar for women and men, gender differences were found for nocebo rates. In the conclusion, we discuss potential implications for clinical trial designs and argue for interventions aimed at optimizing positive expectations of treatment benefit while minimizing the impact of adverse effects.
KW - Antidepressive Agents
KW - Controlled Clinical Trials as Topic
KW - Depression
KW - Humans
KW - Placebo Effect
KW - Research Design
U2 - 10.1098/rstb.2010.0394
DO - 10.1098/rstb.2010.0394
M3 - SCORING: Journal article
C2 - 21576145
VL - 366
SP - 1879
EP - 1888
JO - PHILOS T R SOC B
JF - PHILOS T R SOC B
SN - 0962-8436
IS - 1572
ER -