The novel coronavirus SARS-CoV-2, which causes COVID-19, was first identified in late 2019.1 Older adults became a high-risk, vulnerable population, with numerous international clinical and epidemiological studies reporting high rates of transmission, morbidity, and mortality in this population.2–7 The rapid spread of the disease led health organisations worldwide to issue recommendations aimed at preventing and reducing transmission of the virus,2,8 such as physical distancing and even lockdown measures.8–10

At the beginning of the COVID-19 pandemic, some communications published in scientific journals warned about the detrimental effects of physical distancing and lockdown in older adults. Aubertin-Leheudre and Rolland9 gathered health and physical activity data using an application paired with a fitness tracker or smartwatch, and found a statistically significant decrease in overall physical activity in older adults, specifically in the mean weekly step count. Like other authors, they concluded that decreased physical activity has a negative impact on physical health,9,11,12 increases frailty, and decreases muscle strength and mass.9,12,13

Other studies suggest that the pandemic may have caused mental health problems,11 particularly anxiety, stress,3 distress, irritability, fear, depression,14 uncertainty, distorted perception of risk, somatisation,15 anger, frustration, boredom,12,16 and loneliness.11,16 With the pandemic, we also expected to observe changes in support networks as both lockdown and physical distancing would significantly reduce contact with relatives and friends. It was also suggested that older adults would become more dependent on their children, needing help for such tasks as shopping for everyday necessities.16 Furthermore, older adults may experience difficulty communicating due to limited access to Internet-based services and smartphones and limited familiarity with new technologies.11,16 They were also at greater risk of presenting increased alcohol and tobacco use,15 insomnia,3,14,15 and neurocognitive problems,12,17 and of receiving less cognitive stimulation.11

Several authors have suggested that episodic memory (the capacity to consciously recall experiences and events) is particularly vulnerable to ageing18–20; therefore, it was of vital importance to evaluate the impact of the pandemic and lockdown on this cognitive domain.

The purpose of this study was to describe the characteristics of physical activity, mental health, support networks, and lifestyle in older adults during lockdown due to the COVID-19 pandemic, and to analyse the impact of these factors on memory.

This study provides information about the characteristics of physical exercise, mental health, social support networks, lifestyle, and memory, as well as the association between these variables and objective and subjective memory functioning, in a population of healthy older adults during voluntary lockdown due to the COVID-19 pandemic.

Our results indicate that, during lockdown, our participants perceived an increase in sedentary habits; they also reported being active by performing incidental activities, exercising in sessions of acceptable duration, and walking for at least 10 consecutive minutes an acceptable number of days per week. These data stand in contrast with other results in the literature, as numerous authors had suggested that lockdown may lead to significant decreases in physical exercise in this population.9,11,12 For instance, Okely et al27 reported sedentary habits and a decrease in physical activity, whereas other studies found that total time spent doing physical exercise remained unchanged or even increased significantly,28–30 with walking being the most frequent activity.29 Walking was also the activity preferred by our study participants.

Regarding mental health, we observed symptoms of moderate or severe anxiety (both trait and state) in the whole sample, as well as symptoms of mild to severe depression in approximately a quarter of participants. Furthermore, a study including a sample of older adults reported presence of negative mood states, such as fear of contracting COVID-19 or attending a hospital or medical consultation, perception that the pandemic changed their life, and, to a lesser extent, loneliness, stress, anger, sadness, greater tendency to arguing, and anxiety attacks.

These findings are consistent with the results reported by other authors at the beginning of the pandemic, who identified older adults as a population group at particular risk of developing mental health problems.9,11,16,17 This population group was therefore expected to present anxiety,3,14 depression,14 and negative mood states.12,14,15 Recent studies conducted during the pandemic report anxiety (with rates ranging from 14.4% to 18.8%),31–33 while others have found increased levels of anxiety.30,34,35 Similarly to our results, 2 studies conducted in Cuba found symptoms of anxiety in 100% and 94% of the participants, respectively.36,37 Depressive symptoms have been reported in 17.6%–40% of members of the samples studied during the pandemic29,31–33,38; the percentage of participants reporting depression in our study (24%) lies within that range. Regarding negative mood states, our results are consistent with those of previous studies, which report sadness, distress, fear,39 tension, and significantly higher levels of perceived stress in older adults.30 Our participants also reported negative mood states associated with restrictions due to the pandemic, which led to greater tendency to arguing and fear of attending a hospital.

Regarding social support networks, our results show that participants perceived more support from their family networks than from community and institutional networks. Previous studies have postulated that lockdown and physical distancing must necessarily have a negative impact on such aspects as socialising11,16,17 and perceived family support. This was not the case in our series of Mexican older adults, where lockdown was found to have a positive effect, in line with the results reported by Shaygan and Bahadori.16 These authors report a positive impact of the COVID-19 pandemic, as older adults could rely on their children to solve problems associated with lockdown. In fact, Okely et al27 and Docherty et al30 reported slightly higher levels of social support and interaction among their participants. Regarding social interactions, older adults in our study used different communication tools and media, which enabled them to maintain contact with other people, promoting closeness despite physical distance, and to access a large amount of information to stay informed about the pandemic. The most frequently used media were television and the Internet, and the most frequently used communication tools were text messages and phone calls. The preferred leisure activities were watching television and browsing the Internet. Soon after the onset of the public health emergency, it was suggested that lockdown and isolation would be aggravated by the difficulty faced by many older adults in remotely maintaining contact with family and friends. This difficulty arises from the need to own a device (smartphone, computer, or tablet), to know how to use communication applications (messaging and video calls), and have access to the Internet.11,16,17 Recent studies report that the preferred sources of information are television,29,40 newspapers, the Internet, and radio.29 The main communication tools were phone calls, messaging applications, social media, and email.29 The preferred leisure activities were watching television and using smartphones.40 Our sample presents adequate connectivity and digital literacy, which has an impact on the promotion of support and social interaction. This may be linked to the educational level of the sample, with more than 50% of participants having completed under- or postgraduate studies. In this regard, Dura-Perez et al40 suggest that during lockdown, new technologies have served as a resource for cognitive stimulation, access to information, leisure, and social connection. Maggi et al41 reported that greater perceived social support could result from telephone or online contact with family or friends, and Hamm et al42 noted that their participants felt that during the pandemic, they more frequently communicated and listened to their loved ones thanks to applications and electronic devices.

In terms of lifestyle factors, participants reported an increase in daily consumption of tobacco but not of alcoholic drinks. At the beginning of the pandemic, some researchers suggested that older adults might exhibit risk behaviours such as increased use of alcohol and tobacco.15 However, we did not find recent studies reporting these findings.

Regarding sleep quality in our sample, 46% of participants reported insomnia. Furthermore, the majority reported difficulty in sleeping, especially in terms of the time required to fall asleep, awakenings during the night, waking earlier than desired, and the overall duration of sleep. Several authors had already reported sleep problems and insomnia in older adults during the pandemic.3,14,15 Recent studies found a 46.8% prevalence of insomnia, as well as difficulties in initiating and maintaining sleep,29,32 frequent awakenings29 or waking earlier than desired,29,32 and changes in the sleep pattern.34 Our results confirm previous evidence and support the idea of significant prevalence of insomnia and sleep-related problems in this age group during the COVID-19 pandemic.

The objective memory of our participants was normal to high normal; however, subjective memory was rated as fair. Calderón-Larrañaga et al11 suggested that cognitive function may worsen due to reduced cognitive stimulation during lockdown, while Jiménez-Pavón et al12 recommended engaging in physical exercise during lockdown to prevent cognitive decline. Regarding objective memory, Carbone et al28 conducted a longitudinal study of working memory and long-term memory, finding sustained good functioning. In another study, Qi et al43 observed preserved working memory after 12 weeks of qigong training. It should be noted that our participants reported high levels of social interaction through virtual means and high levels of physical activity during lockdown, which may be associated with the persistence of good objective memory functioning even in conditions of physical isolation. On the other hand, our findings also confirm the trend observed in most recent studies that subjective memory is perceived to function poorly30,41 in 28%39 to 54.3%29 of the participants. Our results highlight the association between depression and perceived memory functioning during lockdown. This may be due to multiple factors present during the health emergency that may have affected emotional and mental health. The negative self-assessment of memory functioning may have been influenced by the possible internalisation of negative attitudes toward ageing,44 as well as negative perceptions about people and their abilities, frequently associated with depression, intensified by the perception of a higher vulnerability to mortality due to COVID-19 in this age group.

The results obtained in our study reveal that objective memory functioning was optimal in our participants. However, from a qualitative viewpoint, participants did report memory deficiencies; therefore, it seems important to include the evaluation of depressive symptoms in the assessment of memory function. Regarding exercise, our findings underscore the importance of maintaining the amount of low- or high-intensity physical activity recommended by the World Health Organization for older adults. Engaging in routine incidental activities and reducing sedentary behaviour also demonstrated a protective effect on cognitive processes and psychosocial well-being. The characteristics of our sample, such as participants’ high socioeconomic status, high level of education, and use of computers, applications, and electronic devices, may have acted as protective factors. Technological instruments may serve as sources of cognitive stimulation or even components of an enriched environment. It is also crucial to focus on maintaining mental health, avoiding negative mood states, and cultivating social support networks. Our results highlight the influence of affective states and sleep quality on perceived memory functioning. Therefore, further research should include samples with different sociodemographic characteristics and at later stages of the COVID-19 pandemic. Finally, if physical and cognitive activity shows a favourable association with episodic memory performance and functioning, this study will help guide health interventions aimed at minimising negative consequences for older adults in the context of highly stressful events, such as the COVID-19 pandemic.

The protocol was approved by the institutional research and ethics committee of Instituto Nacional de Rehabilitación “Luis Guillermo Ibarra Ibarra” (project code 32/21). The project was conducted in accordance with the standards of the Declaration of Helsinki on research involving human subjects.

All participants signed an informed consent form.

This study received no financial support from any institution.