Dementia is generally a chronic clinical syndrome that includes a group of specific degenerative diseases characterized by a marked decline in higher brain functions, such as memory, cognitive capacity, and behavior (1). Dementia causes, in patients, dependence on basic activities of daily living and social and occupational functioning, causing patients to become dependent (2). Globally, around 9.9 million people develop dementia every year, with approximately 63% of cases being observed in low- and middle-income countries (3), and in 2021, there were a total of 55 million people diagnosed with dementia worldwide (4). The annual incidence of dementia ranges from 5 to 10 cases per 1,000 among people 64–68 years of age and 40–60 cases per 1,000 among those aged 80–84 (5). Its prevalence is under 2% in 65–69-year-olds but doubles every 5 years, reaching 10–17% among 80–84-year-olds (5). The World Health Organization (WHO) predicts that in 2030 there will be 78 million people with dementia, this rising to 139 million by 2050 (3). In our setting, the Spanish Statistics Institute estimates that the number of people in Spain with dementia will rise to around 600,000 by 2030 and 1 million by 2050 (5). Given these worrying projections for prevalence and incidence, dementia can be considered one of the greatest challenges for primary health and social care worldwide (1, 6).

Various neurodegenerative disorders and factors contribute to the development of dementia through a progressive and irreversible loss of neurons and brain functioning. Currently, there is no cure for any type of dementia (1). The most common type of dementia is Alzheimer’s disease, accounting for two-thirds of all cases (7), followed by vascular and Lewy body dementia (1). Other forms include mixed dementia, which is commonly seen in elderly adults and in which patients have features of more than one type of dementia, and frontotemporal dementia, which is generally uncommon but more common than other types before old age (>65 years) (8). Dementia affects millions of people and is more common as people grow older (about one-third of all people age 85 or older may have some form of dementia) but it is not a normal part of aging. Many people live into their 90s and beyond without any signs of dementia (1, 4). Dementia develops over the years, from an onset that is considered “presymptomatic phase,” also called preclinical phases of the disease, but in which there are pathological changes which might cause short-term memory loss, and personality or behavioral changes, to overt clinical disease, characterized by not being able to plan or carry out complex tasks (9).

There is no single test for diagnosing dementia (10). The initial evaluation requires the assessment of personal health records as well as cognitive and neurological testing (11). For achieving a diagnosis, health records are an important tool, in that they may help identify a decline in cognitive capacity over time (12). A clinical history should be taken by interviewing both patients themselves, some reporting forgetfulness and others failing to remember details of their medical record or having anosognosia, and close family members (11). However, Cognitive testing provides objective evidence of the presence, severity, and nature of cognitive decline (11, 13). Cognitive Tests should be carried out individually and without family members present, to avoid the patient being distracted (13). There are different types of cognitive tests, with short questionnaires being useful for detecting dementia, while tests covering various domains are more effective for confirming the clinical diagnosis of dementia (10). In this way, the Mini-Mental State Examination (MMSE), developed by Folstein in 1975, is one of the most widely used screening tools for cognitive impairment, and scores are easily influenced by education level. MMSE is poor at identifying early dementia, especially mild cognitive impairment. The MMSE consists of six aspects and a total of 30 questions. MMSE is one of the most widely used cognitive function assessment scales in a clinic and has been translated for use in numerous countries (14–16).

The pandemic of coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus has a considerable impact on people with dementia. Dementia patients are more likely to have adverse medical outcomes with high rates of mortality. In the brain, SARS-CoV-2 has neuroinvasive and neurotropic features with acute and chronic neurovirulent potential (17). Also, dementia patients have also been affected by the measures like isolation and social distancing put in place to control the outbreak, which continue to alter the daily routines of patients and their caregivers (18). Therefore, home confinement is a hostile experience, due to the restrictions on physical, cognitive, and social activities. In our setting, the routines of elderly adults have been disrupted by the cancelation of group activities and the care provided in day centers, which were closed for 3 months, forcing these individuals to stay at home without any care support (19). During confinement due to COVID-19, changes in routines not only affect the person with cognitive impairment, but also determine an overload for the caregiver. The absence of activities of the therapeutic teams, which suspended care services during the quarantine, affects the task of the caregiver and limits her free time (20). This double stress—that of caring for a person with dementia in a context of fear of infection—generates more anxiety and less tolerance for the affected person in some caregivers (21). Other effects of confinement by COVID-19 were anxiety, depression and loneliness suffered by caregivers of patients with dementia (22).

Adult day service centers, such as care homes or adult day care centers (ADCs), provide people with dementia with integrated health and social care for some hours of the day. Several studies have reported the quality of life and care of patients with dementia being better among those who do than those who do not attend ADCs (23, 24). Further, such centers reduce informal caregiver burden and have a positive effect on patients who attend frequently, mainly due to the clinical effectiveness of cognitive therapies they receive (25). These cognitive therapies would encompass a set of non-pharmacological interventions (NPI) that are any non-chemical intervention that is implemented for the benefit of the patient. NPIs, predating modern pharmacology, have been used to improve quality of life, delay deterioration, or relieve pain (26). Cognitive therapies provided in ADCs by health and social workers working with dementia patients and service users in a face-to-face setting have benefits (23, 24) such as: increasing their subjective well-being, mood, and perceived personal satisfaction; reducing anxiety; preventing or improving symptoms of depression; enhancing their sense of self-esteem and social inclusion; and most importantly, improving mental capacity by preserving and most crucially modulating or strengthening cognitive function (24, 25). NPIs are recommended by WHO as tools for reducing the risk of cognitive impairment and dementia with multisectoral interventions (4, 8). Liang et al. (27) have described that NPIs had statistically significant benefits for cognitive function, with Integrated Therapy being the best option for patients with dementia. These authors (28) have suggested that cognitive stimulation and cognitive training, as NPIs, in older adults with mild cognitive impairment significantly improved cognitive function (28). In addition, cognitive training could be the most appropriate method to improve cognitive function in Alzheimer’s patients (29). Moreover, NPIs could reduce psychological symptoms of dementia and maintain or slow decline in cognitive function on psychotic, affective and behavioral subdomains in older adults (26, 30).

However, we hypothesized that the temporary absence, as in confinement during COVID-19, of these NPI could substantially deteriorate the mental health status of dementia patients in social care settings, for example, ADCs. Due to all the above, we assessed, using the MMSE, the effects produced by the COVID-19 pandemic on mental health and cognitive impairment in patients with dementia who were unable to attend their usual ADCs and did not receive NPI as they had been doing until the enforcement of pandemic-related restrictions.

Using the MMSE questionnaire, our pilot study assessed the impact of discontinuing NPIs on cognitive impairment in patients with dementia during the 3-month COVID-19 lockdown. These dementia patients did not attend the ADC of the “Leonese Association of Dementia Patients” (Leon, Spain) to perform the therapeutic work protocol of NPI, due to restrictions related to the COVID-19 pandemic. Our initial hypothesis was partially fulfilled, with a substantial acceleration of the cognitive decline in patients following a markedly lower MMSE questionnaire score during the confinement period, than in the pre-pandemic COVID-19 period. In our study MMSE scores decreased at a rate of more than 10 points/year in one-third (33.8%) of people during the period of home confinement, in contrast to only 5.5% of those who experienced that rate of decline in the months immediately pre-COVID-19. Furthermore, the prediction rule developed considering independent factors for predicting an acceleration in cognitive decline (loss in MMSE score/year before home confinement and the absolute MMSE score just before the start of this lockdown) had a sensitivity of 69% and a specificity of 70.6%.

Our results could show that NPIs, according to WHO guidelines (8, 34), are a very useful tool for stimulating the abilities of people with dementia, slowing down the development of the disease, and improving the person’s remaining abilities (26, 36, 37). For this reason, the interruptions (COVID-19 quarantine) would affect the performance of the person in their daily life, which will result in a worse state of mind and cognition, a decrease in self-esteem, finally achieving a lower quality of life for the person with dementia (38). The COVID-19 pandemic negatively affected older adults’ engagement in behaviors that promote mental health due to the protective measures implemented and the resulting social isolation (39). This was mirrored by previous outbreaks of SARS and Middle East Respiratory Syndrome (MERS) that demonstrated that quarantine has negative effects on mental health, with an increase in psychiatric symptoms (40). Vernuccio et al. (41) have reported a significant increase in the incidence and severity of psychological disorders in people with dementia due to COVID-19 quarantine. Loneliness, social isolation and loss of routine activities could be an important cause of increased anxiety and depression, which would intensify cognitive impairment during the pandemic, due to patients’ inability to adapt to new living conditions and inability to continue daily activities, such as NPIs (39, 41). ADCs for the elderly are a type of daycare center oriented toward continuity and long-duration care. These ADCs are staffed by a team of highly qualified personnel who attend to the social, and health (comprises mental health) needs of frail elderly people, including patients diagnosed with dementia (42). It is known that the attendance of these patients at ADCs have a dual, physical, and psychological positive effect due to the substantial reduction of problems such as social isolation, depression, and anxiety (43).

In the “Leonese Association of Dementia Patients” ADC, we perform cognitive stimulation therapy (CST) 5 days per week for 1 h daily. The CST would be key to maintaining the cognitive functioning of patients with dementia (44). In this sense, Coen et al. (45) demonstrated that CST substantially improved MMSE scores compared to patients without CST. In addition, patients with early stages of dementia have reported beneficial effects on their mental state and delayed cognitive decline post-CST program (46). CST could enhance the effects of cholinesterase inhibitors, which are prescribed to slow cognitive decline, in reducing the rate of cognitive decline (47) and improving scores on the MMSE. These results suggest that CST is one of the important NPI treatment strategies for patients with dementia.

However, Kallio et al. (48) have reported that CST did not affect global cognition in persons with mild to moderate dementia. Thus, another cause of the decrease in the MMSE score could be the social distancing of confinement by COVID-19. Isolation has been associated with a negative impact on physical and mental health, manifesting this in patients with dementia with higher levels of depression, hopelessness, and cognitive impairment (49). ADCs have “green spaces” in the open air such as gardens or fields, as the ADC of the “Leonese Association of Dementia Patients,” allows social interaction with other users and day center staff, in addition to carrying out programmed NPI activities outdoors. Also, country walks help concentration, as they require greater attention than any other environment (50). As a result, all this could help maintain or improve cognitive abilities.

We observed a relationship, not statistically significant, between having less physical activity and a decrease in the MMSE score. The low level of physical activity, for 3 months of COVID-19 confinement, of the day center patients could lead to reduced cognitive stimulation, provided by exercise, compatible with cognitive impairment (51). The physical activity (gerontogymnastics) program would be able to modulate substrates associated with neuroplasticity (neurotrophic signaling, neurogenesis, inflammation, stress response, and antioxidant defense) in the brain, responsible for cognitive and cerebral improvement (52).

The practice of physical activity in outdoor recreational spaces allows patients to reduce internal tension. This eliminates hypertension, increases the mental well-being of the elderly, and modulates their stress levels (53). The elderly who has seen their stress levels reduced see improvement in pathologies such as depression or conditions such as anxiety, reduced vulnerability and loss of skills, self-esteem, and cognitive impairment (54). Therefore, all this impacts a palpable improvement in the physical condition of older adults, which is always an advantage for their mental health to improve. The reduction of stress and the practice of exercise improve the synthesis and release of dopamine in the brain associated with the mesolimbic pathway, and with the calcium-calmodulin dependent pathway, respectively. This increase, in dopamine, modifies and/or affects brain function, potentially inducing beneficial physiological, behavioral and psychological changes (55, 56).

Family members caring for patients with dementia routinely experience stress, physical impairment, and social isolation (57). Dementia patients are a type of population that was first in and last out of strict and prolonged periods of confinement to prevent SARS-CoV-2 infection. Longer periods of confinement result in more severe neuropsychiatric symptoms that directly affect their caregivers, particularly increased caregiver strain (58). The caregivers, included in our study, showed a substantial increase in their tasks with an optimum state of good health. Adult dementia ADCs provide support and relief to caregivers, showing a positive effect on the relationship between family caregivers and dementia patients (59). NPI-based day interventions give family members a break and have a positive psychological impact, associated with improvements in their social and professional lives (60).

Our results suggest that, during the 3-month COVID-19 lockdown, dementia patients who typically attend our ADC to receive our NPI program experienced more rapid cognitive decline. The reported declines in MMSE scores reveal a significant acceleration of cognitive decline during the period of inactivity. This could suggest that our NPIs, focused on slowing cognitive decline, are beneficial and, therefore, necessary in patients with dementia.

The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding authors.

The studies involving human participants were reviewed and approved by the Ethics Committee of the University of León (Spain) with PI No. 2020–13. The patients/participants provided their written informed consent to participate in this study.

LS-V, DF-L, and JS-C: conception and design of the study. LS-V and LB-C: data acquisition. AM-I and LS-V: analysis and interpretation of data. DF-L and JS-C: drafting the manuscript and revising it critically for important intellectual content. All authors have approved the version to be published and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy and integrity of any part of the work are appropriately investigated and resolved.

This work was supported by the Spanish Ministry of Economy and Competitiveness (grant no. MTM2017-86061-C2-1-P) and Department of Education of the Government of Castilla y León and European Regional Development Fund (grant nos. VA005P17 and VA002G18).

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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