Young-Onset Dementia: Clinical Findings and Factors That Delay Early Diagnosis-A Retrospective Observational Study

Background/Objectives: Young-onset dementia (YOD) is a form of dementia where symptoms appear before the age of 65 years with a worse course, a poorer prognosis, and a lower survival rate than late-onset dementia. Psychiatric disorders often entail confusion, which delays their diagnosis and management. This study emphasizes the risk factors and confounders that limit opportunities to provide adequate early diagnoses of YOD. Methods: A retrospective, analytical, and observational study was based on the clinical records of 191 patients with a diagnosis of probable YOD in a medium-complexity hospital between 2009 and 2024. Demographic variables and the characteristics of the population were analyzed. An explanatory linear regression analysis was conducted to highlight the time required for diagnosis beginning at the onset of symptoms. Results: A high proportion of initial misdiagnoses were identified, and most patients were initially diagnosed with psychiatric or neurological disorders other than dementia. The main preventable risk factors were high blood pressure (HBP), type 2 diabetes mellitus (T2DM), and traumatic brain injury (TBI). HBP and the presence of irritability were associated with earlier diagnosis, whereas T2DM and the initial diagnosis of an affective or anxiety disorder were associated with a longer delay prior to diagnosis. Conclusions: Due to delays in seeking care and initial misdiagnoses as affective or anxiety disorders, T2DM is associated with a delayed final dementia diagnosis. In contrast, HBP and irritability were linked to shorter diagnostic times. These findings underscore the need for improved diagnostic capacity, adapted clinical tools, and awareness strategies to promote the early recognition of YOD.