0915 The Effects of Eszopiclone on Spindles, Slow Oscillations and their Coordination in Health and Schizophrenia

Abstract

Introduction: Patients with schizophrenia have sleep spindle deficits that correlate with impaired sleep-dependent memory consolidation. In a previous study of schizophrenia, eszopiclone, a non-benzodiazepine sedative hypnotic, despite increasing spindles, failed to improve memory. Here, we investigated whether this failure reflected that eszopiclone disrupts slow oscillations (SOs) and their coordination with spindles, both of which are critical for memory consolidation. Methods: Twenty-six chronic, medicated patients with schizophrenia (32±8yrs, 21 male) and 29 demographically matched healthy controls participated in a double-blind, placebo-controlled, crossover study. Placebo and eszopiclone visits both involved polysomnography on two consecutive nights. On the second night of each visit, participants trained on the finger tapping motor sequence task (MST) and were tested the following morning. We evaluated eszopiclone effects on SOs (0.5-4Hz), spindles (12-15Hz), SO phase at spindle peak (timing) and the variability of this timing (consistency) during stage 2 non-rapid eye movement sleep and how they related to overnight improvement of MST performance. Results: Regardless of group and condition (eszopiclone, placebo), SO-spindle coordination, both timing and consistency, were stable across nights. While timing did not differ between groups, patients unexpectedly were more consistent (pcorrected=.01). Eszopiclone affected both groups similarly: it increased spindle density (pcorrected