P089 Mental Health and Health-Related QoL in Central Disorders of Hypersomnolence vs Unexplained Excessive Daytime Sleepiness

Abstract Introduction Central Disorders of Hypersomnolence (CDH) (Narcolepsy Type 1, Narcolepsy Type 2, and Idiopathic Hypersomnolence) have an essential element of excessive daytime sleepiness (EDS) despite an adequate duration of sleep. CDH significantly impact mental health and health-related quality of life (QoL). However, less is known about the impact of unexplained EDS (i.e., not better explained by CDH, insomnia, or uncontrolled Obstructive Sleep Apnoea (OSA)) on mental health and health-related QoL. The objective of this study was to compare the mental health and QoL of patients diagnosed with CDH vs unexplained EDS. Methods Patients referred to a sleep psychology service in a major tertiary hospital from January 2022 to May 2024 for management of CDH or unexplained EDS were included. Exclusion criteria were a referral for insomnia, OSA, or circadian rhythm disorder. Data included were the number of sessions and initial Depression Anxiety Stress Scales (DASS-21), Kessler Psychological Distress Scale (K10), EQ-5D-5L, and Insomnia Severity Index (ISI). Results During the assessed period, the service received 31 referrals for EDS (CDH = 19, unexplained EDS = 12). The average number of sleep psychology sessions attended was 4 (range = 0-12). Although the sample was too small to achieve adequate power for analysis, patients with unexplained EDS trended towards higher scores across all mental health and health-related QoL measures than patients with a CDH diagnosis. Discussion This study highlights the importance of studying patients with unexplained EDS and the benefits they may gain from accessing sleep psychology services.