Depressive symptoms and suicidal thoughts in idiopathic hypersomnia: a cross-sectional and longitudinal study

To assess the frequency and factors associated with depressive symptoms, major depressive episode (MDE), suicidal thoughts, and risk in patients with idiopathic hypersomnia (IH), a rare hypersomnolence disorder, compared to controls, and to evaluate their changes after management.

Consecutive untreated adult IH patients, diagnosed in a Reference Center for Rare Hypersomnias, were compared to controls from the general population. All participants completed the Beck Depression Inventory-II (BDI-II), including one item on suicidal thoughts. Patients underwent standardized evaluations with polysomnography (PSG), completed the IH Severity Scale, and self-questionnaires on fatigue, anxiety, and quality of life (QoL). A subgroup underwent the face-to-face Mini-International Neuropsychiatric Interview (MINI) to diagnose past/current MDE and identify suicidal risk. Another subgroup completed the BDI-II again during follow-up, after months of stable treatment.

About 729 participants were included: 265 IH (30.6 ± 9.7 years) and 464 controls (30.5 ± 10.1 years) with no differences in age, sex, or body mass index. Patients had higher odds of moderate/severe depressive symptoms (OR = 7.68; 95% CI = [4.31; 13.7], p < .0001) and suicidal thoughts (OR = 1.68 [1.05; 2.68], p = .03). Patients with moderate/severe BDI-II scores had more severe IH symptoms, more anxiety, fatigue, and lower QoL, without PSG differences. Suicidal thoughts were associated with more anxiety and severe IH symptoms. Patients evaluated by MINI (n = 175) had current MDE in 8%, past MDE in 44%, and suicidal risk in 18.6%. In the 111 patients re-evaluated after treatment, BDI-II scores and fatigue decreased, QoL improved, but suicidal thoughts and anxiety remained unchanged.

Depressive symptoms, past depressive episodes, suicidal ideation, and risk were frequent in IH. Depressive symptoms and suicidal thoughts were associated with IH severity. IH management decreased depressive symptoms without effect on suicidal thoughts. Statement of Significance This study highlights the high frequency of depressive symptoms and suicidal thoughts in individuals with idiopathic hypersomnia (IH), a rare sleep disease under-recognized for its psychiatric burden. By comparing a large cohort of patients with controls and evaluating changes after treatment, it shows that depressive symptoms improve with management, but suicidal thoughts often persist. Patients with moderate-to-severe depressive symptoms and those with suicidal thoughts have more severe IH symptoms and anxiety. These findings underscore the psychiatric burden of IH and the need for comprehensive care. Critical gaps remain in understanding and managing associated psychiatric risks in IH. Future research should explore mechanisms linking IH and depression and suicidality and identify specific strategies to address this unmet clinical need.