Sleep in Schizophrenia and Substance Use Disorders: A Review of the Literature

Abstract

Objective: Despite the high prevalence of sleep disturbances in patients with co-occurring schizophrenia and substance use disorders, very little is known about sleep in this population. This paper reviews the existing literature on sleep in patients with schizophrenia and substance use disorders. Methods: PubMed and Ovid searches were performed using combinations of the terms “sleep,” “schizophrenia,” and names of commonly abused individual substances. Since searches regarding sleep in patients with dual diagnoses returned few results, we also explored the sleep abnormalities inherent in schizophrenia and in substance use disorders separately. Results: Our search identified 1,667 papers and 111 were included for review. We summarized what little is known about primary sleep disorders in this population and identified commonalities in sleep disturbances in each disease with emphasis on underlying pathophysiology as well as the effects of antipsychotics. Conclusions: Given the high prevalence of sleep abnormalities in patients with schizophrenia and substance use disorders, the relative paucity of clinical guidance, and the potential impact that sleep disorders can have on the course of disease, there is a need for additional research regarding sleep in patients with co-occurring schizophrenia and substance use disorders to improve recognition and management of these comorbid conditions.

Keywords:

• sleep
• dual diagnosis
• schizophrenia
• co-occurring disorders

Notes

Several of the research studies reviewed use an alternate term, respiratory disturbance index (RDI), instead of apnea-hypopnea index (AHI). In each of these studies, the RDI was calculated the same way as the AHI (i.e., respiratory-effort related arousals were not included in arriving at the RDI). For simplicity, only the term AHI is used here.