[Sleep disorders in psychiatric diseases. Epidemiological aspects]

Area of Science:

• Sleep Medicine
• Psychiatry
• Epidemiology

Context:

• Limited epidemiological data exists on sleep disturbances and psychiatric diseases.
• The Association of Sleep Disorders Centers classification (1979) categorizes sleep disorders into insomnia, hypersomnia, schedule issues, and parasomnias.
• Psychiatric disorders are evaluated using DSM criteria, but sleep disorder evaluation lacks equivalent standardized criteria.

Purpose:

• To review the epidemiological evidence linking sleep disturbances with psychiatric diseases.
• To highlight the prevalence and characteristics of insomnia and hypersomnia.
• To discuss the specific sleep alterations observed in major depressive disorders.

Summary:

• Insomnia affects 9-31% of the population, with higher prevalence in women, the elderly, and those with lower education.
• Subjective insomnia, characterized by distress, is frequently associated with anxiety and depression.
• Depressive disorders are found in 21-40% of insomniacs, versus 0-1% of non-insomniacs. Anxiety disorders are present in 13-24% of insomniacs versus 3-10% of non-insomniacs.
• Sleep alterations in depression include decreased slow-wave sleep and REM sleep latency, with the latter potentially specific to depression.
• Hypersomnia affects 2-4%, often linked to sleep apnea syndrome and narcolepsy.

Impact:

• Establishes a strong correlation between sleep disturbances and psychiatric conditions, particularly depression and anxiety.
• Underscores the need for standardized diagnostic criteria for sleep disorders.
• Provides insights into the complex interplay between sleep, aging, and mental health.