Since returning from the Sleep Clinic and Narcolepsy Center at Stanford University in the United States in 1999, the author has diagnosed and treated over 1000 patients with narcolepsy.

The symptoms of narcolepsy typically feature severe daytime sleepiness and cataplexy, the latter manifesting as muscle weakness triggered by emotions such as laughter or anger [3]. Other symptoms may include sleep paralysis, characterized by an inability to move upon awakening, and hypnagogic hallucinations, which are vivid dreams experienced when falling asleep [4]. The International Classification of Sleep Disorders–Third Edition divides narcolepsy into type 1, marked by both daytime sleepiness and cataplexy, and type 2, indicated by daytime sleepiness alone [5]. About 70% of all cases are classified as type 1 narcolepsy, with the remainder categorized as type 2 narcolepsy. Patients with severe cataplexy face significant challenges in performing daily activities including work, necessitating community and governmental support [6].

A 32-year-old man, exhibiting symptoms of sudden muscle strength loss and collapsing while walking, presented at the sleep clinic. Previously, he had visited several hospitals for his daytime sleepiness and collapsing, yet he received no accurate diagnosis until being evaluated at our facility where he was finally diagnosed with narcolepsy with cataplexy.

The aforementioned patient, a carpenter who constructs houses, experiences not only excessive daytime sleepiness but also cataplexy, characterized by the loss of muscle tone triggered by emotional responses. This cataplexy poses risk during the use of tools, and the severity of his narcolepsy symptoms has rendered him unable to continue working. I have encountered numerous narcolepsy patients who are unable to work due to severe cataplexy and excessive daytime sleepiness.

The Disability Diagnosis Benefits for narcolepsy, which provide support for patients with severe narcolepsy in Korea, were initiated in April 2021. However, only a few patients have received a disability diagnosis thus far.

The current criteria for diagnosing disability due to narcolepsy do not consider the severity of the disease but instead focus on the presence of accompanying psychiatric symptoms. The current disability diagnosis of narcolepsy requires psychiatric symptoms such as hallucinations, delusions, hypnagogic hallucinations, mood swings, behavioral problems, and cognitive impairment in addition to narcolepsy symptoms. However, narcolepsy is a sleep disorder, not a psychiatric one; therefore, psychiatric symptoms are irrelevant to its diagnosis [7]. Moreover, patients with psychiatric symptoms receive disability diagnoses as having a psychiatric disease, regardless of the presence of narcolepsy.

Moreover, caused by a deficiency in hypocretin—a wakefulness-promoting neurotransmitter produced in the brain [8]—narcolepsy is a significant sleep disorder. Consequently, classifying narcolepsy as a psychiatric disorder is mistaken. In clinical practice, not only psychiatrists but also neurologists, otolaryngologists, and pulmonologists who manage sleep clinics diagnose and treat this disorder. Thus, the disability diagnosis of narcolepsy should not be confined to psychiatrists.

According to data from the Korean National Health Insurance from 2010 to 2019, there were approximately 8700 patients undergoing treatment for narcolepsy, with about 5900 diagnosed with type 1 narcolepsy [9]. We can estimate that 5%– 10% of type 1 narcolepsy patients (approximately 295–590 patients) might require disability diagnoses.

The criteria for diagnosing disability due to narcolepsy should reflect the severity of narcolepsy symptoms such as daytime sleepiness and cataplexy severity, and the impairment these cause in daily functioning [10]. Including “accompanying psychiatric symptoms” in the current disability diagnosis does not provide an accurate basis for assessing disability in narcolepsy patients. This requirement should be revised to focus solely on the symptoms of narcolepsy.

This revision is supported by the consensus among sleep physicians in Korean sleep societies, as well as narcolepsy patients and members of the Korean Narcolepsy Patients Association.