“A wolf in sheep's clothing”: when so‐called placebo interventions are not what they seem

Abstract

Where appropriate, placebo interventions have been used, assuming no impact of treatment on the placebo effect.

Efficacy of biologically-directed daylight therapy on sleep and circadian rhythm in Parkinson's disease: a randomised, double-blind, parallel-group, active-controlled, phase 2 clinical trial

“…The potential for a placebo effect must be considered in any intervention study. 48 No prior light intervention study has applied a satisfactory alternative spectrum to evaluate such effects. 5 , 6 However, including a third, “no light” intervention arm would have jeopardised the double-blind design of this study.…”