The Night and Day Challenge of Sleep Disorders and Insomnia: A Narrative Review

Abstract

This is a narrative review of sleep disorders, especially chronic insomnia, as a primary diagnosis or as a comorbid diagnosis associated with different psychiatric and organic diseases. The epidemiological evidence is reviewed, the diagnostic criteria most frequently used in clinical practice are examined, and a series of therapeutic recommendations for the correct treatment of this pathology is presented. Sleep disorders are very prevalent in the general population (one-third experiences difficulty with sleep initiation/maintenance at least once a week, and about 6–15% meet the criteria for insomnia disorders), but remain relatively poorly understood and frequently overlooked by healthcare professionals. Prevalence estimates of insomnia disorder vary between 5% and 20%. Sleep disorders co-exist with psychiatric and medical conditions with an interactive and bidirectional relationship. About 70–80% of psychiatric patients show some sleep disturbance and there is a correlation between the severity of the sleep disturbance and the severity of the psychopathology. Untreated sleep disorders increase the risk of cardiovascular events, cognitive impairment, motor vehicle accidents, obesity, diabetes, and efficiency and safety at work, leading to increased all-cause healthcare utilization and being a strong predictor of sick leave or disability pension and poor quality of life. Sleep disorders can cause drowsiness or excessive daytime sleepiness, which can lead to functional impairment in 15% of the general adult population. Sleep quality should be a routine target in the evaluation of patients with psychiatric and non-psychiatric diseases to ensure sleep health based on early diagnosis and adequate therapeutic approaches.