Géraud Dautzenberg

General introduction

Montreal Cognitive Assessment ‘MoCA’: The MoCA is a widely used short screening tool for MCI and mild dementia (MD). It was introduced and validated in French and English in 2005 (Nasreddine et al. , 2005). Until now, it has been validated in multiple settings and languages, although not in psychiatry ( mocatest.org ). It is now recommended by several institutions and guidelines, including Cochrane and Alzheimer International, to use it as a screener for cognitive impairment (Davis et al. , 2013; Alzheimer’s disease International, 2016). Its use and popularity are growing fast, and it seems to be rivalling the MMSE. There are 867 publications to date (d.d. January 2022) with the MoCA as the main subject (mentioned in the title) and even several more using the MoCA in their study to measure cognition (9722 with MoCA as a keyword with Embase). The MoCA consists of one page covering the cognitive domains of executive function and visuospatial abilities, naming, short-term memory, attention and working memory, language, concentration, verbal abstraction, and orientation. It can be performed within 10 minutes, with a maximum score of 30, indicating that no errors were made. Scores can be corrected for low education according to instructions by adding one point to the total score of patients with 12 years of education or less. Three validated versions differ from each other in minor ways to avoid a learning curve. The nature or subject of the questions remained the same, but the numbers or words differed between versions. For example, version one asks to subtract 7 from 100, whereas version 2 asks to subtract 6 from 100. The originally suggested cut-off for the diagnosis of cognitive impairment was a score of < 26 (less than 26). In the original study, the MoCA was compared to the MMSE. The results showed that it was superior to the MMSE in detecting MCI and mild AD. At a cut-off < 26, the sensitivity of the MoCA was 90% for MCI and 100% for mild AD. This was 18% and 78% for the MMSE, respectively. The MoCA’s specificity was 87% compared to 100% for the MMSE. Indicating that the MoCA was too difficult for 13% of the non impaired, but the MMSE was too easy for 82% of the mildly impaired and 12% of the people with mild dementia. However, the results of the Dutch version in patients with cognitive symptoms in a geriatrics department deviated from this for unknown reasons, with a sensitivity and specificity of 72% and 73% for MCI, respectively, compared to healthy controls (Thissen et al. , 2010). Validation has also been performed in several specific populations, including vascular dementia (Ihara et al. , 2013), frontotemporal dementia (Freitas et al. , 2012) and Alzheimer’s disease (Freitas et al. , 2013).

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