P027 Dream characteristics are sex-specific in REM Sleep Behaviour Disorder and healthy older adults

Introduction REM sleep behaviour disorder (RBD) is strongly associated with neurodegenerative disease (NDD), and the isolated form is a known prodrome of several alpha-synuclein-related NDD’s. RBD is difficult to diagnose, and screening questionnaires focus on vivid and aggressive dream content, but these characteristics may be more common to males, leading to underdiagnosis of RBD in females. It is important to explore dream characteristics in males and females to improve screening methods and identify RBD early in its trajectory to NDD. Method Adults aged 50+ years were recruited from the community to complete the REM Sleep Behaviour Disorder Single-Question Screen (RBD1Q; to identify pRBD) and the Mannheim Dream Questionnaire (MADRE). The MADRE includes 20 questions enquiring about different characteristics of dreaming, such as dream recall, emotional intensity, and frequency of nightmares. Results 1,809 participants completed the RBD1Q and MADRE, and 129 (7.1%) screened positive for pRBD (mean (SD) age 62 (7.7) years; 58% female). In the pRBD group, females reported more nightmares related to waking-life experiences than males. The pRBD group recalled dreams more often, experienced more lucid dreams and more nightmares during childhood compared to non-pRBD controls. In the control group, females reported more negative emotional tone to their dreams, had a stronger interest in dreams and attributed more meaning to dreams, than males Discussion This study found sex-specific differences in dream characteristics in pRBD and controls. This is relevant to RBD screening questionnaires as questions on nightmares related to waking life may aid identification of females with pRBD.