Dear Editor, Narcolepsy is a rare but disabling rapid eye movement sleep disorder, with an estimated prevalence of 0.02%–0.05%. Studies consistently report an average diagnostic delay of 7–10 years from symptom onset. During this prolonged interval, patients are often treated for mood or anxiety disorders, while the underlying sleep disorder remains unrecognized, leading to reduced quality of life and increased morbidity. Narcolepsy is considered to be an autoimmune disorder with destruction of hypocretin-producing neurons in the lateral hypothalamus.1-3 This case report highlights the clinical overlap between narcolepsy and depressive disorders, an overlap that frequently contributes to delayed diagnosis in the psychiatric settings. A 43-year-old male presented to the psychiatry outpatient department with persistent excessive daytime sleepiness, an overwhelming urge to sleep during routine activities, and repeated episodes of having to stop his vehicle while driving to take short naps. Despite taking multiple naps during the day, he consistently reported feeling unrefreshed. He also described low mood, reduced concentration, and declining work efficiency, which significantly affected his occupational functioning. The patient denied any nocturnal sleep disturbances such as difficulty initiating or maintaining sleep, frequent awakenings, or early morning awakening. There was no history of substance use and no medical comorbidities were identified on evaluation. In view of his affective symptoms and cognitive complaints, an initial diagnosis of depressive disorder was considered. He was started on tablet sertraline 25 mg once daily, which was gradually up-titrated to a therapeutic dose. However, follow-up revealed only minimal improvement, with excessive daytime sleepiness and functional impairment remaining essentially unchanged. The persistence of marked daytime sleepiness despite adequate antidepressant treatment, along with the nonrestorative nature of naps and preserved nocturnal sleep, prompted a reconsideration of the diagnosis. Subsequent detailed clinical evaluation of sleeping patterns led to a diagnosis of narcolepsy.4 In retrospect, many of the patient’s depressive symptoms appeared to be secondary to chronic sleepiness and its psychosocial consequences rather than indicative of a primary mood disorder. Following the modified diagnosis, the patient was started on tablet modafinil 200 mg in the morning, increased to 400 mg/day on subsequent follow-ups.5 The patient reported improvement in his daytime drowsiness and felt more refreshed during the day. Over the next few weeks, his occupational functioning improved, and he reported a subjective improvement in the low mood that had previously been present. Following this, the patient was lost to followup. Narcolepsy can closely resemble depressive disorder because the core features of both conditions significantly overlap in daily functioning, mood and cognition. The most prominent symptom of narcolepsy - excessive daytime sedation often presents as reduced motivation and fatigue which can be mistaken for depression. This case also illustrates how narcolepsy may be misidentified as depression, particularly in the absence of classic symptoms such as cataplexy, sleep paralysis, or hypnagogic hallucinations.6 System-level factors may further contribute to this diagnostic delay, including limited access to sleep medicine services, constraints on the availability of sleep laboratories, and the relative underrepresentation of sleep disorders in routine psychiatric training and assessment frameworks. Psychiatrists are uniquely positioned to reduce this diagnostic gap. Routine screening for pathological excessive daytime sleepiness, using brief instruments such as the Epworth Sleepiness Scale, should be considered in patients presenting with depressive symptoms accompanied by prominent fatigue or cognitive complaints. Excessive daytime sleepiness that persists despite adequate antidepressant treatment should prompt evaluation for central disorders of hypersomnolence. Early recognition and timely referral can prevent unnecessary pharmacological exposure, reduce functional impairment, and substantially improve the quality of life for affected individuals. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Ahluwalia et al. (Mon,) studied this question.