Variations of Sleep Patterns and Their Relations with Positive and Negative Domains of Schizophrenia in Eastern Indian Population

Abstract

Objectives: Schizophrenia is a persistent and incapacitating psychiatric condition characterized by symptoms with positive, negative, affective, and cognitive domains. Sleep disturbances represent an important facet of this disorder, impacting both the quality of life and influencing its overall outcome. In the cross-sectional study, we intended to investigate the polysomnographic findings of patients with schizophrenia showing predominantly positive symptoms as opposed to those presenting with predominantly negative symptoms and also as compared to normal population. Methods: This study had a cross-sectional design, involving the recruitment of 60 medication-naive patients diagnosed with schizophrenia according to the ICD-10 criteria and 30 study participants representing normal population. The cases were subdivided into two groups: one characterized by predominantly positive symptoms and the other characterized by predominantly negative symptoms. Both the groups received overnight polysomnography, and study variables were recorded. Results: All the sleep parameters were deranged in patients with schizophrenia as compared to normal controls in the general population, with significantly more pronounced differences found in those with predominant positive symptoms for most variables (p < 0.001). The only exception was the duration of N3 (slow-wave sleep) which was significantly decreased in patients with negative symptoms compared to those with positive symptoms (p < 0.001). But no significant differences were found between the negative and positive symptom domain groups in mean rapid eye movement (REM) latency, duration of N1 and N2 sleep, and total percentage of REM sleep. Conclusion: This study highlights substantial variations in sleep patterns between the negative and positive symptom domains of schizophrenia and also as compared to the general population. Further study is imperative to explore the link between circadian integrity and symptoms of the various domains of schizophrenia.

Keywords

• nonrapid eye movement sleep; polysomnography; rapid eye movement sleep; slow-wave sleep