In a recent study published in The Lancet Healthy Longevity, researchers assessed the results of the coronavirus disease 2019 (COVID-19) pandemic on the cognition of older adults in the UK (UK).
Concerns have emerged in regards to the neuropsychological effects of social restrictions imposed in the course of the COVID-19 pandemic, that are particularly relevant for older adults. Social restrictions have reduced networking and call, and social isolation has been related to loneliness. Some studies have established links between COVID-19 and cognitive effects. Nevertheless, the impact of the pandemic per se on cognition is less clear.
Study: Cognitive decline in older adults within the UK during and after the COVID-19 pandemic: a longitudinal evaluation of PROTECT study data. Image Credit: Lightspring / Shutterstock
Concerning the study
The current study investigated the results of the COVID-19 pandemic on older adults’ cognition within the UK. The researchers used data from the PROTECT study initiated in 2015 that collected data throughout the pandemic. Specifically, data from the yr before the pandemic and the primary and second pandemic years were analyzed.
Participants were no less than 50 years old on the time of knowledge collection and weren’t diagnosed with dementia. At baseline, demographic data, akin to age, sex, education level, and ethnicity, were collected. Subjects accomplished cognitive tests, akin to verbal reasoning, paired associated learning, self-ordered search, and digit span tests.
Cumulative scores from digit span, self-ordered search, and paired associate learning tasks served because the composite measure for working memory. Participants took the tests at each annual time point. Further, annual questionnaires were administered to acquire health-related data. The patient-health questionnaire was used to evaluate depression. Loneliness was examined using a broader questionnaire on mental health.
Data on the frequency of physical activity and alcohol consumption were obtained. Using cognition rating because the final result, timepoint because the explanatory variable, and sex and age as covariates, a linear mixed-effects model was constructed. In sensitivity analyses, individuals with cancer or Parkinson’s disease were excluded, and the change in cognition in the primary pandemic yr was compared with that within the second yr.
Moreover, the first evaluation was repeated on two sub-groups – participants with mild cognitive impairment and people with a past COVID-19 diagnosis. Hierarchical multivariable regression was utilized in the sub-analysis of individual cohorts (overall cohort and two sub-groups) to look at associations of altered cognition.
Findings
Neuropsychological data from the PROTECT study were available for 3,142 individuals on the pre-pandemic time point. Of those, 10% and 13.6% didn’t provide data for the primary and second pandemic years, respectively. The pre-pandemic trajectories didn’t significantly differ between those that accomplished assessments in the course of the pandemic and those that didn’t.
Cognitive performance evaluation revealed a major worsening of working memory and executive function in the primary pandemic yr. The effect on working memory persevered within the second yr. When individuals with a COVID-19 history or mild cognitive impairment were excluded, the differences in working memory and executive function were still significant between the pre-pandemic yr and the primary pandemic yr. Participants showed the next rate of cognitive changes in the course of the pandemic than before.
Executive function and dealing memory in the entire cohort decreased by a mean of 0.61% and 0.64% within the pre-pandemic yr but by 1.24% and 1.16% in the course of the pandemic, respectively. This higher rate of decline within the pandemic was also evident in each sub-groups. Depression and loneliness in individuals with mild cognitive impairment were related to cognitive decline, and depression was related to cognitive decline within the COVID-19 sub-group in the primary pandemic yr.
Within the second pandemic yr, reduced exercise frequency was the one factor affecting executive function in the entire cohort. Nevertheless, higher alcohol consumption, depression, and loneliness were related to poor working memory within the mild cognitive impairment group within the second yr. Likewise, within the COVID-19 sub-group, associations were observed between working memory and reduced exercise frequency, depression, and loneliness.
Conclusions
The study revealed an accelerated decline in executive function and dealing memory in older UK adults in the primary pandemic yr. Nevertheless, the worsening of working memory was sustained in the course of the second yr, when restrictions were lifted. The magnitude of cognitive change was notable, with over 50% higher decline in executive function and dealing memory.
Sub-group evaluation similarly indicated the identical effect but more rapid and pronounced cognitive decline than the general cohort. Furthermore, the evaluation also highlighted associations between alcohol intake, depression, loneliness, and physical activity with cognitive decline in the course of the pandemic. As such, it’s needed to handle these changes in lifestyle behaviors. The researchers speculate that interventions for these (lifestyle) behaviors may gain advantage cognition.