Refining early dementia detection: Diagnostic utility of the Mattis Dementia Rating Scale-2 in differentiating multidomain amnestic mild cognitive impairment and early Alzheimer's disease.

Background: Early differentiation between amnestic multidomain mild cognitive impairment (aMCI-md) and Alzheimer's disease (AD) is critical for timely diagnosis and care planning. The Mattis Dementia Rating Scale-2 (DRS-2) is a multidomain cognitive screening tool with potential value in detecting early neurodegenerative changes, though its performance in distinguishing aMCI-md from early AD remains underexplored. Objective: To evaluate the diagnostic accuracy of the DRS-2 total and subscale scores in a Spanish clinical cohort by comparing cognitively unimpaired individuals, patients with aMCI-md, and those with early AD. Methods: We conducted a cross-sectional study including 684 participants: 333 cognitively healthy controls, 141 with aMCI-md, and 210 with early AD. The DRS-2 was administered as part of a neuropsychological battery. Receiver operating characteristic curves, area under the curve (AUC), and optimal cut-off values were used to assess discriminative performance. Results: The DRS-2 total score and the Memory and Initiation/Perseveration subscales demonstrated good discriminative accuracy across all diagnostic contrasts. In the most clinically relevant comparison (aMCI-md vs. early AD), both the total score and Memory subscale reached an AUC of .87, while Initiation/Perseveration followed closely (AUC = .83). The total score yielded 87.2% accuracy (cut-off = 126), and Memory alone achieved 86.6% accuracy (cut-off = 19). Attention and Construction subscales consistently showed limited diagnostic value. Conclusion: The DRS-2, particularly the Memory and Initiation/Perseveration subscales, appears to be a reliable tool for distinguishing the early stages of cognitive impairment, supporting its clinical use for early diagnosis and risk stratification in memory clinic settings.