Assessment of sleep quality in bipolar euthymic patients

Abstract

Objective: Sleep quality is affected in bipolar disorder even in euthymic episodes. The aim of this study was to assess sleep quality in bipolar euthymic patients, determine related clinical characteristics and evaluate its effects on functionality.

Methods: A total of 122 outpatients were included. Scales were used to confirm that patients were euthymic. Mini Mental Test was performed to exclude patients with a diagnosis of dementia. A data form for socio-demographic features and clinical characteristics of bipolar disorder have been completed. SCID-I and SCID II were used. The general features of sleep were investigated by General Sleep Questionnaire. All patients completed Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Bipolar Disorder Functioning Questionnaire.

Results: 56.5% of our sample had poor sleep quality. Patients with poor sleep had a longer time to fall asleep and more frequent waking after sleep onset. Caffeine use and smoking, history of suicide attempts, seasonality, comorbidity of lifetime anxiety, somatoform and impulse control disorders, using antidepressant medication and administration of electroconvulsive therapy were significantly higher; emotional and intellectual functioning, household relations, taking initiative, self-sufficiency and total functionality were lower in bipolar patients with poor sleep quality (p<0.05). The strongest predictor of sleep quality problem was seasonality, recording an odds ratio of 3.91.

Conclusions: Sleep quality is closely related with clinical features of bipolar disorder. Sleep quality is affected negatively in euthymic episodes of bipolar disorder and poor sleep quality cause loss in functionality. Assessment of sleep disturbances routinely in psychiatric interviews and dealing with sleep problems regardless mood episodes may improve sleep quality, thereby functionality and quality of life.