A scoping review on the time to diagnosis, early symptoms, and the barriers and facilitators of diagnosis in young-onset dementia

Background Young-onset dementia (YOD) occurs when symptoms start before age 65 and affects about 3.9 million people globally. Variability in first symptoms, the young age, and prevalent non-cognitive symptoms pose challenges in recognizing YOD, leading to diagnostic delays. Better awareness and recognition of warning signs in primary care is essential for early YOD diagnosis, facilitating access to appropriate services and informal care arrangements. Objective To gain insights into the prediagnostic phase of YOD by exploring literature on early symptoms and factors influencing a timely diagnosis. Methods A literature search was conducted across PubMed, Embase, Web of Science, and PsycInfo. Two independent reviewers screened 5862 titles and abstracts and assessed 790 full texts. Data extraction used a standardized form, including time to diagnosis, early symptoms, barriers, and facilitators to YOD diagnosis. Review reporting followed PRISMA-ScR guidelines. Focus group discussions with people with YOD, caregivers, and healthcare professionals (HCPs) contextualized the review findings. Results We included 225 studies. Time to diagnosis ranged from 4 months to 15 years across dementia subtypes. Early symptoms included memory problems, language difficulties, disorientation, personality changes, delusions, hallucinations, apathy, and depression. HCPs, people with YOD, and their caregivers often lacked awareness of YOD, which hindered diagnosis. However, persistence in seeking medical care, YOD-related services, and couples’ agreements to seek professional help were essential facilitators. Conclusions Early signs of YOD include cognitive, behavioral, and affective symptoms. Lack of YOD awareness hinders diagnosis, highlighting the need to raise awareness among HCPs and the community to promote early identification.