The Impact of the COVID-19 Pandemic and Lockdown on Mild Cognitive Impairment, Alzheimer's Disease and Dementia With Lewy Bodies in China: A 1-Year Follow-Up Study

Background: While the lockdown strategies taken by many countries effectively limited the spread of COVID-19, those were thought to have a negative impact on older people. This study aimed to investigate the impact of lockdown on cognitive function and neuropsychiatric symptoms over a 1-year follow-up period in patients with mild cognitive impairment (MCI), Alzheimer's disease (AD) and dementia with Lewy bodies (DLB).

Methods: We enrolled consecutive patients with MCI, probable AD or DLB who were receiving outpatient memory care before the COVID-19 pandemic and followed-up with them after 1 year by face-to-face during the COVID-19 pandemic to assess changes in physical activity, social contact, cognitive function and neuropsychiatric symptoms (NPS).

Results: Total 105 probable AD, 50 MCI and 22 probable DLB patients were included and completed the 1-year follow-up between October 31 and November 30, 2020. Among the respondents, 42% of MCI, 54.3% of AD and 72.7% of DLB patients had a decline in MMSE scores and 54.4% of DLB patients had worsening Neuropsychiatric inventory (NPI) scores. Patients with DLB showed a more rapid decline of MMSE than those with AD. Diminished physical activity and social contact might have hastened the deterioration of cognition and the worsening of NPS.

Conclusion: Social isolation and physical inactivity even after strict lockdown for at least 6 months were correlated with accelerated decline of cognitive function and NPS in patients with AD and DLB.