Health professionals mistaking narcolepsy for psychiatric conditions is real. But so is failing to recognize depression, anxiety, and other comorbidities in people with narcolepsy.

Study after study show that people with narcolepsy are frequently misdiagnosed with psychiatric conditions. Just this year, an abstract published in a supplement to the journal Neurology found that more than half of people with narcolepsy experience one or more wrong diagnoses initially, most commonly depression (31.3%), anxiety disorder (16.3%), and attention deficit/hyperactivity disorder (16.2%).1 This is a known problem that delays the diagnosis—and treatment—of narcolepsy while the person bounces around through different healthcare disciplines.

But once the person lands in the sleep physician’s office, a less recognized disservice can begin: the treatment of narcolepsy without evaluation for potential comorbid psychiatric disorders.

Some narcolepsy comorbidities are present at the time of initial diagnosis and others may develop over time. So screening for psychiatric conditions is an undervalued but important step for sleep professionals to take at regular intervals with their patients with narcolepsy.

An Olmsted County, Minn, community-based study that analyzed longitudinal data from the years 2000 to 2014 found depression to be highly comorbid with narcolepsy, affecting 39.7% of narcolepsy patients at diagnosis, with an increase to 50% at the end of the study. By contrast, 14.7% of healthy controls were affected by depression at the study onset and 21.7% at the study’s end—a significantly elevated odds ratio for people with narcolepsy of 4.88 at start and 3.79 at last observation. Psychiatric disorders in general also had a significantly elevated odds ratio both at diagnosis and after the observation period. Anxiety disorder was only significantly elevated at the time of diagnosis; it become non-significant after observation due to increasing incidence in the control cohort. Still, anxiety disorder was identified in 20.6% of people with narcolepsy at diagnosis and in 25.0% of people with narcolepsy later.2

Offering screening and referrals to patients of both sexes is important. “Patterns of higher psychiatric frequencies were similar for males and females,” said Chad Ruoff, MD, a sleep physician at Kaiser Permanente in Woodland Hills, Calif, at 2019 Los Angeles Narcolepsy Education Day, an event hosted by Wake Up Narcolepsy. Ruoff is first author of a recent study that evaluates psychiatric comorbidity patterns in patients with a narcolepsy diagnosis in the United States. All mental illness categories were significantly more prevalent in patients with narcolepsy versus controls, with the highest excess prevalence for mood, depressive, and anxiety disorders. Also of note, the highest excess prevalence for anxiety and mood disorders was identified in the younger age groups.3 Be methodical, Ruoff advised. “You may create a different problem by escalating stimulants. Work on the diagnosis and just be careful,” he said.

With this information, it’s clear that some people with narcolepsy who receive a psychiatric diagnosis before their narcolepsy diagnosis do have diagnosable and treatable mental health conditions—but that solo diagnosis too is not enough.

A 2015-2016 study of an outpatient psychiatric clinic in Singapore screened patients with mood disorder, anxiety disorder, and schizophrenia for sleep disorder symptoms. The prevalence for symptoms of narcolepsy was 12.5%.4

That’s a compelling case for sleep physicians to create bidirectional referral relationships with mental health professionals in their geographic area. As the authors say, “Identifying and addressing sleep disorders in early stages may have a positive impact on the prognosis and quality of life of a psychiatric patient.4

Sree Roy is editor of Sleep Review.

References
1. Ohayon M, Thorpy M, Black J, et al. Misdiagnoses and comorbidities among participants in the Nexus Narcolepsy Registry. Neurology. Apr 2019:92(15 Suppl):3.6-037.
2. Cohen A, Mandrekar J, St Louis EK, et al. Comorbidities in a community sample of narcolepsy. Sleep Med. 2018 Mar;43:14-8.
3. Ruoff CM, Reaven NL, Funk SE, et al. High rates of psychiatric comorbidity in narcolepsy: findings from the Burden of Narcolepsy Disease (BOND) study of 9,312 patients in the United States. J Clin Psychiatry. 2017 Feb;78(2):171-6.
4. Hombali A, Seow E, Yuan Q, et al. Prevalence and correlates of sleep disorder symptoms in psychiatric disorders. Psychiatry Res. 2018 Jul 6. pii: S0165-1781(18)30268-3.