| Observational study: prospective longitudinal cohort  

Cognitive decline in older adults in the UK during and after the COVID-19 pandemic: a longitudinal analysis of PROTECT study data

This longitudinal study analysed digital cognitive tests’ data measuring executive functions (EF) and working memory (WM) from 3142 older adults (> 50 years-old) participating in the PROTECT study at three timepoints: before COVID-19 pandemic, and after 1 and 2 years. Subgroup analyses were performed in patients with mild cognitive impairment (MCI) and in those with a history of COVID-19. Significant worsening of EF and WM was observed in the first year of the pandemic across the whole cohort (EF: effect size 0.15, WM: effect size 0.51). This was present also in patients with MCI (effect size 0.13 and 0.40), and people who had COVID-19 (effect size 0.24 and 0.46). After 1 year, a decline in EF was significantly associated with reduced exercise, while increased alcohol use had a negative impact on WM across the whole cohort. In those who had COVID-19, depression was associated with worse EF, while in MCI participants loneliness was related to reduced WM abilities. After 2 years reduced exercise continued to affect EF across the whole cohort, and worsening WM was associated with increased alcohol use, loneliness, and depression in MCI participants, and reduced exercise, loneliness and depression in those with past COVID-19.