“Waking up in the morning is very, very hard. I don’t hear alarms, smell smoke, or feel water. There are very few things that can wake me up, and it’s also very hard for the person who wakes me up. On good days, it takes 30 minutes. On bad days, it can take 2 hours,” Marie Drouvé, a 25-year-old postgraduate student in Cologne, Germany, who lives with narcolepsy, told Medscape News Europe.

Drouvé began experiencing symptoms in 2011 and wasn’t officially diagnosed until 2016. Her 5-year wait is not unusual; a European study found many patients face years-long delays before receiving a diagnosis.

Diagnostic delays stem from uneven access to specialist testing, a lack of reliable biomarkers, and symptom overlap with common mental health and attention disorders. 

The result is a set of conditions that can upend education, work, and relationships long before a name is put to them and that still rely largely on imperfect tools and off-label treatments even after a diagnosis is made.

The Diagnostic Maze

Hypersomnolence disorders involve abnormally high daytime sleepiness, long sleep duration, severe sleep inertia, and cognitive slowing. They include narcolepsy types 1 and 2, idiopathic hypersomnia, and Kleine-Levin syndrome (KLS). While relatively uncommon — narcolepsy types 1 or 2 affect about 42 per 100,000 people globally; idiopathic hypersomnia affects about 20-50 per million; KLS about 1-5 per million — their impact is wide-ranging, with studies describing profound effects on psychological well-being, daily activities, relationships, school and work, and physical health.

“Access to specialist testing also varies widely across Europe, and many patients still experience long delays, sometimes approaching a decade, from symptom onset to diagnosis,” Kristoffer Bothelius, PhD, clinical psychologist and somnologist at Uppsala University Hospital, Uppsala, Sweden, told Medscape News Europe.

Ulf Kallweit, MD, PhD, professor of neurology at the University of Witten/Herdecke, Witten, Germany, noted that awareness among general practitioners and specialists remains limited, and that reliable biomarkers are lacking; factors that compound delays alongside high rates of comorbid depression, anxiety, chronic fatigue, and attention disorders that can lead to misdiagnosis.

Not much has changed in how these conditions are diagnosed, said Kallweit. Diagnosis still rests on clinical history; sleep studies such as polysomnography and the Multiple Sleep Latency Test (MSLT); and, for narcolepsy type 1, cerebrospinal fluid orexin measurements.

Bothelius added that today’s tools are largely tuned to narcolepsy; there are no known biomarkers for other hypersomnolence disorders, and their mechanisms remain elusive.

Although the MSLT is useful for narcolepsy type 1, it’s limited for distinguishing narcolepsy type 2 from idiopathic hypersomnia, pushing clinicians to rely on longitudinal assessments that can misclassify patients.

Gert Jan Lammers, MD, PhD, professor of neurology at Leiden University, Leiden, Netherlands, pointed to diagnostic criteria themselves as a barrier. “The overly strict criteria, which are not based on scientific evidence, mean that people with serious limitations do not receive treatment,” he said. He advocates analyses of large databases that include raw clinical and ancillary data from all people with excessive daytime sleepiness, not just those already labeled with hypersomnolence disorders. “In my opinion, searching for biomarkers or pathophysiology while maintaining the current classification has proven to be a futile endeavor,” he said, noting early steps via the European Narcolepsy Network.

Treatment: Symptom Relief, Not Cure

According to Kallweit, many patients improve with treatment, but daily life often remains constrained. Current therapies manage symptoms rather than cure disease, and efficacy may wane or be limited by side effects. Approved options in Europe largely focus on narcolepsy; for idiopathic hypersomnia and KLS, off-label approaches are common and guidelines are sparse.

Idiopathic hypersomnia is typically managed with stimulants such as modafinil or methylphenidate; some patients use activating antidepressants like bupropion or sodium oxybate, Kallweit said. Serdexmethylphenidate received orphan medicine status in May 2024 for idiopathic hypersomnia. For KLS, lithium, valproic acid, or lamotrigine may be used prophylactically, though evidence is limited and potential adverse effects can outweigh benefits; stimulants like modafinil may support wakefulness during episodes but with modest effects.

There is broad optimism around orexin agonists for narcolepsy type 1. What distinguishes these agents, said Bothelius, is that they aim to restore orexin signaling rather than compensate for it; potentially the “beginning of a more mechanism-based treatment era.” A histamine 3 receptor agonist, pitolisant, has shown promise for idiopathic hypersomnia, but there is nothing new for KLS, Kallweit noted. “More effective and individualized treatments are needed. Data on lifestyle interventions are still lacking,” he added.

Beyond Medication

Drouvé says that attention to mental health is essential. “Ideally, psychological support should become a regular part of treating narcolepsy,” she said. “Right now, those things mostly depend on the individual’s initiative. I think this really needs to change.” A 2025 study on patient experiences in idiopathic hypersomnia described the existential dilemma of “sleeping one’s life away,” alongside guilt and shame; acceptance and self-compassion emerged as key coping strategies.

Drouvé has been in therapy for 2.5 years, which “helps a lot,” she said, and is experimenting with an assistance dog, Akoda, to support morning awakenings and safety during emergencies. She is covering training costs herself because public funding is not available.

“Others also face issues with their health insurance, which often refuses to cover certain treatment methods. But with narcolepsy, it’s all about trying different approaches to find out what works for each individual,” she said.

Bothelius reported being involved in research sponsored by Takeda related to the development of orexin-2 receptor agonists for central hypersomnias but has no paid consultancy or advisory role with the company. He has also received lecture honoraria and a consultant fee from Idorsia in relation to daridorexant, a dual orexin receptor antagonist used in the treatment of insomnia. Kallweit reported being on the advisory board of Takeda, Bioproject, and Pharmanovia. Lammers reported being a former (5 years ago) consultant and member of advisory boards on narcolepsy for Jazz Pharmaceuticals and UCB Pharma. Drouvé has received compensation for taking part in studies linked to her condition for market research purposes. 

Annie Lennon is a medical journalist. Her writing appears on Medscape Medical News, WebMD, and Medical News Today, among other outlets.