This study assesses to what extent the Mini-Mental State Exam and the Montreal Cognitive Assessment scores may predict the presence of dementia in a sample of typical old age psychiatric patients who may or may not have temporally or permanently reduced cognitive abilities.
A total of 141 inpatients completed the Mini-Mental State Exam and the Montreal Cognitive Assessment at arrival. All patients were subsequently diagnosed during their stay at the age-psychiatric unit. Receiver operating characteristics and analysis of variance were used to compare the results of the two tests for different patient groups.
The Montreal Cognitive Assessment is slightly more sensitive and specific than the Mini-Mental State Exam for dementia prediction. Age, sex, and education only account for approximately 2% of the variance in both tests. Patients with more than one diagnosis across the diagnostic groups included in this study (dementia, psychoses, affective disorder, and depression) performed significantly poorer on both tests than patients with a single diagnosis.
Both tests are efficient in detecting cognitive impairment, but neither test can effectively exclude other reasons for low test results in our sample of elderly psychiatric patients. The sensitivity for ruling out dementia is 27 points for the Mini-Mental State Exam and 23 points for the Montreal Cognitive Assessment in the current patient sample.