Schizophrenia patients with predominantly positive symptoms have more disturbed sleep-wake cycles measured by actigraphy

Sleep disturbances are widespread in schizophrenia, and one important concern is to determine the impact of this disruption on self-reported sleep quality and quality of life (QoL). Our aim was to evaluate the sleep-wake cycle in a sample of patients with schizophrenia (SZ), and whether sleep patterns differ between patients with predominantly negative versus predominantly positive symptoms, as well as its impact on sleep quality and QoL Twenty-three SZ outpatients were studied with 24 h continuous wrist-actigraphy during 7 days. The quality of sleep was assessed with the Pittsburgh Sleep Quality Index (PSQI), and the self-reported QoL was evaluated with the World Health Organization Quality of Life - Abbreviated version (WHOQOL-Bref). About half of the studied population presented an irregular sleep-wake cycle. We found a trend for more disrupted sleep-wake patterns in patients with predominantly positive symptoms, who also had a trend self-reported worse quality of sleep and worse QoL in all domains. Overall, patients with worse self-reported QoL demonstrated worse sleep quality. Our findings suggest that SZ patients are frequently affected with sleep and circadian rhythm disruptions; these may have a negative impact on rehabilitation strategies. Moreover, poor sleep may play a role in sustaining poor quality of life in SZ patients. (C) 2011 Elsevier Ireland Ltd. All rights reserved.