Abstract
Insomnia is a pervasive and often debilitating sleep disorder that profoundly affects health and overall wellbeing. This comprehensive review focuses on the historical context, clinical significance, diagnostic criteria, investigative methods, and global treatment guidelines for insomnia. Historically, references to insomnia have appeared in ancient Egyptian and Greek texts, but it was not until the 19th century that they were rigorously studied and classified. Notable individuals, including Vincent van Gogh, Franz Kafka, and Marilyn Monroe, have struggled publicly with insomnia, underscoring its widespread nature. The pathophysiology of insomnia is multifactorial, involving physiological, psychological, and environmental factors. Hyperarousal, dysregulation of the sleep-wake cycle, and neurotransmitter imbalances are central to its development. Insomnia can be categorized into acute, chronic, comorbid, idiopathic, and behavioral types. Epidemiological studies have revealed that up to 30% of adults experience insomnia, with a higher prevalence among women, older adults, and those with a lower socioeconomic status. Insomnia is associated with adverse health outcomes, including cardiovascular diseases, metabolic disorders, cognitive impairment, and increased mortality risk. The COVID-19 pandemic has exacerbated insomnia owing to stress and lifestyle changes. Diagnosis involves a comprehensive assessment, including sleep history, physical examination, and objective evaluations, such as polysomnography. Treatment combines pharmacological and non-pharmacological interventions with cognitive behavioral therapy for insomnia as the first-line approach. Pharmacotherapy includes benzodiazepines, non-benzodiazepine hypnotics, antidepressants, melatonin, and orexin receptor antagonists. Guidelines from the American Academy of Sleep Medicine and the European Sleep Research Society emphasize individualized, evidence-based treatment plans to improve sleep quality and overall health.