Depression occurs often in narcolepsy, but improves with treatment of sleep disorder

Patients with narcolepsy type 1 frequently experienced depression, depressive symptoms, suicidal thoughts and risk for suicide, especially those who have untreated narcolepsy, according to study findings published in Neurology.

However, the researchers also found that treatment for narcolepsy type 1 (NT1) improved depressive symptoms and suicidal thoughts.

“For decades, patients with narcolepsy have complained of depressive symptoms,” Lucie Barateau, MD, of CHU Montpellier in France, and colleagues wrote. “In addition, the presence of [a] clinically-defined major depressive episode, suicidal thoughts and suicide risks have been seldom investigated in NT1, although sleep disturbances are often associated with suicidality.”

Barateau and colleagues assessed depressive symptoms and suicidal thoughts among treated vs. untreated adults with NT1 vs. controls, changes after beginning pharmacotherapy and risk factors for a major depressive episode and suicide in a cross-sectional and longitudinal analysis.

The total study population included 297 patients with NT1 (age, 39±17 years), 172 of whom were not taking medications, and 346 controls (age, 38±16 years). Researchers administered the Beck Depression Inventory (BDI-II) self-questionnaire to all patients, which included one item on suicidal thoughts.

A subgroup of 101 drug-free patients with NT1 completed the BDI-II a second time while on treatment. In 162 patients with NT1, researchers performed the face-to-face Mini International Neuropsychiatric Interview (MINI) to formally diagnose current major depressive episodes and suicide risk.

Patients who were not treated with pharmacotherapy more frequently had more severe depressive symptoms compared with patients who were (minimal: 75 vs. 91; mild: 45 vs. 12; moderate to severe: 52 vs. 22). Researchers found an independent association in multivariate analysis between more severe symptoms of insomnia (OR = 1.23; 95% CI, 1.09-1.38) and narcolepsy (OR = 1.08; 95% CI, 1.02-1.14) with moderate to severe symptoms of depression. Patients who had moderate to severe symptoms of depression also had more frequent symptoms of insomnia and narcolepsy, including excessive daytime sleepiness, disturbed nocturnal sleep, cataplexy, sleep paralysis, sleep-related hallucinations and autonomic dysfunctions, as well as lower levels of educational attainment and quality of life.

These results remained unchanged following adjustments for treatment, according to Barateau and colleagues. After beginning treatment, patients’ mean reported questionnaire scores demonstrated less severity of depressive symptoms and suicidal thoughts compared with the initial evaluation (Epworth sleepiness scale: 18.38 vs. 14.1; European quality of life five-dimensions questionnaire, visual analog scale: 56.42 vs. 66.84; Insomnia Severity Index (ISI): 14.85 vs. 11.73; Narcolepsy Severity Scale (NSS): 32.58 vs. 24.2; SCOPA-AUT [a measure of autonomic dysfunction]: 11.88 vs. 12.33; BDI-II: 16.31 vs. 12.38).

Patients who were at risk for suicide (untreated: 22; treated: 5) had more frequent and more severe symptoms compared with patients who were not (NSS: 35.6±10.63 vs. 28.61±11.06; sleep paralysis frequency: 70.4% vs. 46.6%; ISI: 17.6±4.9 vs. 13.5±5.6). In multivariate analysis, only the ISI score correlated independently with suicidal ideation (OR = 1.11; 95% CI, 1.01-1.24).

“Our study in a large cohort of well-characterized patients with NT1 showed that depressive symptoms are more frequent in adults with NT1 than in controls, and also in drug-free than in treated patients. We confirmed the high frequency of major depressive episodes and suicide risk in the NT1 group,” the researchers wrote. “As they were often underreported by patients, physicians should carry out a more systematic screening of depressive symptoms and suicidality in patients with narcolepsy. We highlighted that the psychological burden associated with narcolepsy can be substantially improved by its management.”