Mood Disorders and Dysautonomia in Patients Diagnosed with Idiopathic Hypersomnia: A Retrospective Analysis (2000-2023).

Background/Objectives: There is limited data on well-documented comorbidities with polysomnography (PSG)/multiple sleep latency test (MSLT) findings in idiopathic hypersomnia (IH). We aimed to characterize the clinical, PSG/MSLT characteristics of IH patients in our health network. Methods: We reviewed charts of all IH cases between 2000 and 2023, extracting clinical features, comorbidities, and PSG/MSLT findings. Results: One hundred forty-two patients (83.80% female) with IH were included. Compared to those without mood disorders, both major depressive disorder (MDD) and anxiety patients were older at onset (27.10 ± 8.32 and 26.76 ± 8.40 versus 23.23 ± 6.94 and 24.05 ± 7.31 years; p = 0.003 and p = 0.042) and had lower ESS (15 versus 19; 15.67 versus 17.75; p < 0.0001), more disrupted sleep (28 (36.36%) versus 8 (12.31%); p = 0.001; 24 (35.82%) versus 12 (16%); p = 0.007), and less sleep inertia (30 (38.96%) versus 38 (58.46%); p = 0.021; 26 (38.81%) versus 42 (56%); p = 0.04). Fifteen patients with dysautonomia disorders presented at an earlier age (21.80 ± 6.60 versus 25.75 ± 8, p = 0.0682). On MSLT, MDD, anxiety, and dysautonomia patients had longer sleep latencies than the non-affected counterparts (6.40 (5.40-7.60) minutes versus 3.60 (2.60-5.40) min., <0.0001; 6.20 (5.20-7.40) versus 4 (2.60-6.40) minutes; p < 0.0001; 7.40 (6-7.80) versus 5.40 (3-7); p = 0.008). MDD and anxiety cases had fewer sleep onset REM periods (7 (9.09%) versus 16 (24.62%), p = 0.0124 and 6 (8.96%) versus 17 (22.67%), p = 0.0388) compared to those not affected by these disorders. Conclusions: Our study highlights the importance of recognizing mood disorders and dysautonomia in patients diagnosed with IH. Further research may elucidate management strategies for these patients.