Research progress on the first‐night effect in polysomnography studies

Abstract The first‐night effect (FNE) is a prevalent occurrence in sleep monitoring that can impact the accuracy of monitoring results, encompassing both FNE and reverse first‐night effect. FNE is characterized by extended sleep onset latency, reduced total sleep time, diminished sleep efficiency, prolonged wake‐time after sleep onset, among other manifestations. The physiological and psychological mechanisms underlying FNE are primarily linked to acute stress induced by the environment and heightened levels of anxiety, involving the default mode network. FNE exhibits varying manifestations and impacts across individuals of different age groups and genetic predispositions. We also discuss the influence of placebo and sedative‐hypnotics on FNE. Understanding these factors is crucial for guiding clinicians and technologists in standardizing polysomnography (PSG) practices and improving the accuracy of sleep disorder diagnoses.