Steeper memory decline after COVID-19 lockdown measures.

BACKGROUND: During COVID-19 lockdown measures, memory clinic patients reported worries for faster cognitive decline, due to loss of structure and feelings of loneliness and depression. We aimed to investigate the impact of the COVID-19 lockdown on rate of cognitive decline in a mixed memory clinic population, compared to matched historical controls. METHODS: We included patients who visited Alzheimer Center Amsterdam 6 months to 1 week before the first Dutch COVID-19 lockdown, and had a second visit 1 year later, after this lockdown period (n = 113; 66 ± 7 years old; 30% female; n = 55 dementia, n = 31 mild cognitive impairment (MCI), n = 18 subjective cognitive decline (SCD), n = 9 postponed diagnosis). Historical controls (visit in 2016/2017 and second visit 1 year later (n = 640)) were matched 1:1 to lockdown patients by optimal Mahalanobis distance matching (both groups n = 113). Groups were well matched. Differences between lockdown patients and historical controls over time in Mini-Mental State Examination, Trail Making Test part A and B, Rey-Auditory Verbal Learning Test (RAVLT) immediate and delayed recall, and category fluency scores were analyzed using linear mixed effect models with random intercepts. We examined differences in rate of cognitive decline between whole groups, and after stratification in SCD, MCI, and dementia separately. RESULTS: Lockdown patients had a faster rate of memory decline compared to controls on both RAVLT immediate [B(SE) = - 2.62 (1.07), p = 0.015] and delayed recall [B(SE) = - 1.07 (0.34), p = 0.002]. Stratification by syndrome diagnosis showed that this effect was largely attributable to non-demented participants, as we observed faster memory decline during lockdown in SCD and MCI (RAVLT immediate [SCD: B(SE) = - 6.85 (2.97), p = 0.027; MCI: B(SE) = - 6.14 (1.78), p = 0.001] and delayed recall [SCD: B(SE) = - 2.45 (1.11), p = 0.035; MCI: B(SE) = - 1.50 (0.51), p = 0.005]), but not in dementia. CONCLUSION: Memory clinic patients, specifically in pre-dementia stages, showed faster memory decline during COVID-19 lockdown, providing evidence that lockdown regulations had a deleterious effect on brain health. In individuals that may have been able to deal with accumulating, subclinical neuropathology under normal and structured circumstances, the additional stress of lockdown regulations may have acted as a "second hit," resulting in less beneficial disease trajectory.

The impact of COVID‐19 lockdown on cognitive decline over time

Background During the COVID‐19 pandemic, memory clinic patients reported worries for faster cognitive decline as a consequence of lockdown measures, e.g. loss of structure and feelings of loneliness and depression. We aimed to investigate the impact of the COVID‐19 lockdown on cognitive decline over time in a mixed memory clinic population, compared to historical controls. Method We included patients who visited Alzheimer Center Amsterdam six months to a week before the first COVID‐19 lockdown in the Netherlands (mid‐March 2020), and a second visit one year later, after this lockdown period (n = 114;67±7 years old;30% female;Mini‐Mental State Examination (MMSE): 25±3;diagnosis: n = 55 dementia, n = 32 mild cognitive impairment, n = 18 subjective cognitive decline, n = 9 postponed diagnosis). We selected historical controls with a visit in 2016 or 2017 and a second visit one year later (n = 641). Historical controls were matched 1:1 to patients during COVID‐19 lockdown by optimal Mahalanobis distance matching based on age, sex, diagnosis, MMSE, type of visit (baseline/follow‐up) and time between the first and second visit. Matching was successful and led to balanced groups (both n = 114) on all matching variables (table 1). We used linear mixed models with terms for time, group (i.e. lockdown patients vs. historical controls) and the interaction between time and group. Outcome measures were MMSE, Trail Making Test part A and B, Rey‐Auditory Verbal Learning Test (RAVLT) immediate and delayed recall and category fluency. Result As expected, there was no effect of group on baseline test performance for any of the tests. We found significant interactions between time and group for RAVLT immediate recall [B(SE) = ‐2.74(1.07), p = 0.011] and delayed recall [B(SE) = ‐1.07(0.34), p = 0.002], indicating steeper cognitive decline during lockdown. In non‐matched historical controls, we found similar results;significant interactions between group and time for RAVLT immediate recall [B(SE) = ‐3.34(0.80), p<0.001] and delayed recall [B(SE) = ‐0.94(0.23), p<0.001], and additionally steeper decline on category fluency [B(SE) = ‐1.42(0.51), p = 0.005]. Conclusion Memory clinic patients during COVID‐19 lockdown show steeper decline in memory than matched historical controls, providing evidence that lockdown regulations contributed to faster cognitive decline.