[Insomnia--state of the science]

Area of Science:

• Sleep Medicine
• Psychiatry
• Genetics

Background:

• Traditional insomnia classifications (ICD-10, DSM-IV) faced criticism for oversimplifying insomnia's complexity.
• Advancements include the International Classification of Sleep Disorders (ICSD-2) and Research Diagnostic Criteria (RDC).
• The DSM-5 introduced 'insomnia disorder,' moving beyond primary/secondary distinctions.

Purpose of the Study:

• To review the evolution of insomnia diagnosis and the current understanding of its etiology.
• To highlight the evidence supporting cognitive-behavioral therapy for insomnia (CBT-I) as a primary treatment.
• To discuss challenges in CBT-I accessibility and propose stepped-care models for improved insomnia management.

Main Methods:

• Literature review of diagnostic systems for insomnia.
• Examination of etiological models, including genetic/epigenetic factors, the three P model, and hyperarousal.
• Analysis of evidence for cognitive-behavioral therapy for insomnia (CBT-I) effectiveness.
• Discussion of healthcare system limitations and stepped-care approaches.

Main Results:

• Diagnostic criteria for insomnia have progressed towards greater specificity.
• Genetic and epigenetic factors, alongside the three P model and hyperarousal, are key to understanding insomnia pathophysiology.
• Cognitive-behavioral therapy for insomnia (CBT-I) is empirically supported as a first-line treatment.
• Limited healthcare resources hinder widespread CBT-I implementation.

Conclusions:

• The diagnosis and understanding of insomnia have significantly advanced.
• Cognitive-behavioral therapy for insomnia (CBT-I) is the most effective treatment, but access remains a challenge.
• Stepped-care models, integrating various levels of intervention, are crucial for improving insomnia treatment accessibility.