The Impact of the COVID-19 Pandemic on the Cognition of People with Dementia

(1) Background: To limit the COVID-19 outbreak, the Italian government implemented social restrictions that may have had psychological and cognitive repercussions on people with dementia. We aimed to analyze cognitive decline during the pandemic year in people evaluated in a memory clinic in northern Italy, the epicenter of COVID-19 spread. (2) Methods: A single-center retrospective study was carried out, including individuals with annual follow-up evaluated in three different years (2020-GROUP, 2019-GROUP, 2018-GROUP). We performed an intergroup comparison of cognitive decline over a one-year follow-up, and an intragroup comparison in the 2020-GROUP to analyze the five-year cognitive decline trajectory, as measured by the MMSE. (3) Results: The 2020-GROUP showed a significant loss of MMSE points per year in the considered follow-up period compared with the 2019-GROUP and 2018-GROUP (p = 0.021). Demographics, clinical features, and the other analyzed variables, including rate of diagnosis, therapy, and comorbidities, did not significantly differ between groups. The five-year cognitive decline trajectory confirmed a significant worsening of cognitive decline between 2019 and 2020 (p < 0.001), while the decrease in MMSE scores was not statistically significant between previous time points. (4) Conclusions: COVID-19 pandemic measures have induced a significant worsening of cognitive decline in people with dementia, needing more careful assistance to minimize the adverse effects of social isolation in case of future lockdowns.