Domain specificity of the subtests of the mini-mental state examination

Objective: To examine the convergent and, for the first time to our knowledge, the divergent validity of 4 of the subtests of the Mini-Mental State Examination (MMSE): attention, naming, memory, and copy. Method: Participants included 126 memory-impaired individuals (mean age, 74 years). Because the naming subtest showed no variability, we did not analyze it further. Results: The convergent validity of the attention, memory, and copy subtests was confirmed with Spearman rank correlation coefficient. Each MMSE subtest was significantly related to a parallel neuropsychological test. We measured divergent validity by testing the difference between the MMSE subtest correlation with its parallel neuropsychological test and its nonparallel neuropsychological test. The MMSE subtests of attention and memory showed similar relationships with their parallel neuropsychological tests as they did with nonparallel neuropsychological tests of attention, memory, and naming. These 2 subtests, however, did show divergence from a neuropsychological test of copy, most likely indicating that these 2 MMSE subtests are measuring the verbal (and not the performance) domain. The MMSE subtest of copy showed the poorest convergent and divergent validity. Conclusions: The 3 subtests did not show sufficient divergent validity to warrant a conclusion of their domain specificity. Thus, when a more detailed diagnostic profile is required, a thorough neuropsychological evaluation will provide a more valid description of an individual's cognitive profile.