“The Latin word for sleeplessness was originally a virtue — Roman generals boasted of it as proof that they were too devoted to the republic to rest.”
Insomnia is Latin, from in- (not) and somnus (sleep). In classical Latin, insomnia was not primarily a medical complaint. It was a description of wakefulness, often with connotations of vigilance and dedication. Pliny the Elder praised the insomnia of scholars and soldiers. Virgil described the watchful insomnia of Aeneas as a quality of leadership. To be insomniac was to be alert when others slept — a sign of duty, not disease.
The medical reframing began in the medieval period, when Galen's humoral theories shaped how European physicians understood sleep disorders. Insomnia became associated with an excess of dry heat, a condition requiring cooling treatments — lettuce, opium, warm baths. By the Renaissance, insomnia had lost its heroic associations and become a symptom. Thomas Willis, the seventeenth-century English physician who gave neurology its name, described insomnia as a disorder of the 'animal spirits' that flowed through the nerves.
The nineteenth century industrialized sleep and, with it, insomnia. Factory schedules, gas lighting, and urban noise created new patterns of sleeplessness. In 1869, George Beard coined the term 'neurasthenia' for the exhaustion he attributed to modern civilization, and insomnia was its most common symptom. The word had completed its reversal: from Roman virtue to Victorian disease. The same wakefulness that Pliny admired was now a medical condition requiring treatment.
The global sleep aid market was valued at over $78 billion in 2023. Cognitive behavioral therapy for insomnia, or CBT-I, is now considered the first-line treatment, ahead of medication. The word itself appears in pharmaceutical advertisements, app store descriptions, and podcast titles. Insomnia has become so common that it feels modern, but the Latin word has been in continuous use for over two thousand years. Only the judgment attached to it has changed.
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Today
Roughly 30% of adults report symptoms of insomnia, and about 10% meet the criteria for chronic insomnia disorder. The condition costs the U.S. economy an estimated $63 billion annually in lost productivity. It is one of the most complained-about symptoms in primary care, and one of the most inadequately treated. Most people who cannot sleep receive either nothing or a prescription. The evidence-based treatment — CBT-I — remains underused because there are not enough trained therapists to deliver it.
Pliny would not recognize the modern insomniac. For him, the sleepless person was a hero, too committed to rest. For us, the sleepless person is a patient, too wired to shut down. The word has not changed. The world around it has. Romans lit oil lamps and went to bed with the dark. We carry screens that simulate daylight at midnight and wonder why we cannot sleep.
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