Investigating the clinical utility of biomarkers and other novel tests in younger onset neurocognitive disorders: the BeYOND study, protocol for a longitudinal clinical study in a real-world setting.

BackgroundYounger-onset dementia (YOD) can be challenging to diagnose due to its younger age of onset, heterogeneous aetiologies and broad range of presentations. Misdiagnosis is common with psychiatric conditions often diagnosed initially and diagnostic delay of five years is common. More information is needed to better understand and diagnose YOD, including the nature of symptom onset, progression of the disease, the relationship between cognition and functional outcomes for patients and carers, imaging changes and novel biomarkers. This paper reports on the background behind the "Investigating the clinical utility of biomarkers and other novel tests in younger-onset neurocognitive disorders", the BeYOND study, and its methodology. MethodsBeYOND is a clinically-oriented "real-world" longitudinal study that follows younger people presenting with an onset of neuropsychiatric symptoms [≤] 65 years of age. We aim to collect information on participants cognition, neuroimaging, mental health, and blood and cerebrospinal fluid (CSF) biomarkers at 18-month time-points over 3 years. We also aim to collect information regarding the experience of carers and/or family of participants. ConclusionSerial assessment of symptomatology, cognition, imaging, and blood and CSF biomarkers will be correlated with eventual diagnosis to determine the usefulness of these measures in determining a confident diagnosis. In addition, repeat measurements of the mental health and well-being of the participant and that of their carers/family while they traverse their diagnostic journey will provide important information about service provision and how they can be better supported.