Biphasic feature of placebo response in primary insomnia: pooled analysis of data from randomized controlled clinical trials of orexin receptor antagonists

Objectives The placebo response to orexin receptor antagonists in primary insomnia is little-known. Our aim was, therefore, to conduct a systematic review of placebo-controlled randomized clinical trials to characterize placebo response. Methods We performed a comprehensive literature search for randomized, placebo-controlled, double-blind clinical trials evaluating the efficacy of orexin receptor antagonists addressing primary insomnia. To pool...