The SOMNUS study: Real-world burden of narcolepsy in Spanish adults

Narcolepsy is a chronic neurological disorder characterized by excessive daytime sleepiness and other disabling symptoms, with cataplexy distinguishing type 1 (NT1) from type 2 (NT2). Despite being a well-defined condition, it remains poorly understood by the general public and medical community. We aimed to describe the clinical characteristics, diagnostic pathway, and real-world burden of Spanish adults with narcolepsy.

Multicentre, observational study across 12 hospitals from different Spanish autonomous communities. Data were collected retrospectively from medical records and cross-sectionally from patient interviews.

210 patients were included (NT1: 74.8%, NT2: 25.2%). Median diagnostic delay was 6.3 years for NT1 and 2.9 years for NT2, with prior misdiagnosis in ∼15%. At the study visit, 84.1% and 83.0% patients with NT1 and NT2 respectively were receiving pharmacological treatment. In NT1 and NT2, quality of life was impaired despite treatment, with quality of life scores around 24% lower than in age-matched general population. Approximately 50% of NT1 and NT2 patients reported anxiety or depression, and over 40% limitations in daily activities. Reduced productivity was reported by 61.7% in NT1 and 62.2% in NT2 patients, while limited career advancement affected 54.3% and 40.0%, respectively. Permanent disability or sick leave affected 10.9% (NT1) and 6.4% (NT2) among employed patients of working age.

Narcolepsy imposes a considerable clinical, functional, and psychosocial burden in Spanish adults, with significant diagnostic delay and high disease burden. These findings underscore the need for better awareness, earlier diagnosis, and more effective management.