Effects of Eszopiclone on Sleep and Memory in Schizophrenia

Sleep spindles, a defining oscillation of stage 2 non-rapid eye movement sleep (N2), are strongly linked to memory and IQ in healthy individuals. Schizophrenia is characterized by a spindle deficit that correlates with deficient sleep-dependent memory consolidation, symptom severity, IQ and executive function. In a small pilot study of schizophrenia patients, eszopiclone , significantly increased sleep spindles but its effect on memory was not significant. Here, in a larger double-blind, placebo-controlled, cross-over design study, we investigated whether eszopiclone can both increase spindle density and improve memory consolidation. Chronic, medicated schizophrenia outpatients and demographically-matched healthy control participants were randomly assigned to receive either placebo first or 3mg of eszopiclone first for two consecutive nights with high density polysomnography. Placebo and eszopiclone visits were one week apart. Participants were trained on the Motor Sequence Task (MST) at bedtime of the second night of each visit and tested the following morning to probe sleep-dependent motor memory consolidation.