Comparison of behavioral and psychological symptoms in early‐onset and late‐onset Alzheimer's disease

BACKGROUND: When comparing with early-onset Alzheimer's disease (EO-AD) and late-onset Alzheimer's disease (LO-AD), some symptomatological differences in clinical features can be seen between them. Rapid progression, more severe language problems or visuospatial dysfunction occur more often in EO-AD patients. However, there have been very few reports about the differences in behavioral and psychological symptoms between these two groups. AIM: The aim of this study was to demonstrate the differences in behavioral symptoms between EO-AD and LO-AD groups. METHOD: Three hundred and seven consecutive outpatients with AD were put into an EO-AD group (46 patients) or a LO-AD group (261 patients). Comprehensive assessment batteries, including the Neuropsychiatric Inventory (NPI), were administered at the first medical assessment. RESULTS: Significant differences were found between the EO-AD and LO-AD groups in terms of NPI total score (EO-AD: 10.3 +/- 10.9, LO-AD: 17.8 +/- 17.0, p = 0.004) and number of patients who experienced each NPI subscale score (delusion; EO-AD: 13.0%, LO-AD: 50.6%, p < 0.001). There were no differences in cognitive functions or dementia severity between two groups. CONCLUSION: In EO-AD, behavioral and psychological symptoms are relatively fewer than LO-AD at the first medical assessment.