Comparison of pre-diagnostic signs and symptoms of young-onset dementia and late-onset dementia in the general practice.

BackgroundDementia can occur in older adults (late-onset dementia; LOD) or before age 65 (young-onset dementia; YOD). YOD often involves more heterogeneous subtypes and atypical early symptoms, making it harder for general practitioners (GPs) to recognize YOD early.ObjectiveTo identify differences in pre-diagnostic signs and symptoms between persons with YOD and LOD at the GP, enabling earlier recognition of YOD.MethodsThis case-control study used data from GP records of 88 YOD cases and 174 LOD controls from the Research Network Family Medicine database, matched by sex and GP practice. Persons diagnosed before age 70 were included in the YOD group to account for diagnostic delay. Symptoms up to five years before diagnosis were grouped into eight categories. Differences in symptom presence were analyzed per year using binary logistic regression.ResultsCompared to LOD, YOD cases had significantly higher odds of reporting affective symptoms two (OR = 2.43, 95%CI = 1.30-4.51) and one year (OR = 2.36, 95%CI = 1.35-4.13) before diagnosis. Social indicators were also more common in YOD five (OR = 4.84, 95%CI = 1.09-21.44), four (OR = 3.75, 95%CI = 1.27-11.09), and one (OR = 4.00, 95%CI = 2.33-6.86) year before diagnosis. Gait disturbances were less frequent in YOD at four (OR = 0.33, 95%CI = 0.12-0.89) and two (OR = 0.43, 95%CI = 0.20-0.91) years prior. Surprisingly, no significant differences emerged for cognitive symptoms.ConclusionsYOD differs from LOD in several symptom categories up to five years before diagnosis. These findings provide insight into the pre-diagnostic trajectory of YOD and may support earlier recognition.