In 2019 in Wuhan in China, a number of cases of unexplained pneumonia occurred. In January 2020, the Chinese Center For Disease Control and Prevention (CCDC) detected a novel coronavirus in a patient’s throat sample (Zhu et al., 2020). The World Health Organization (WHO) named the virus 2019-nCoV (“2019 novel coronavirus”). The name was subsequently changed to “severe acute respiratory syndrome coronavirus 2” (SARS-CoV-2) and the disease caused by the virus was named “coronavirus disease” (COVID-19) (World Health Organization [WHO], 2021). The SARS-CoV-2 virus soon spread to the whole world (Zhu et al., 2020).

In order to limit the spread of the virus, social distancing and the use of personal protective equipment were recommended. The authorities of different countries reacted in various ways, which involved the application of various measures such as closing schools, businesses and other public meeting places, cancelling public events or introducing restrictions in public transport (McKenzie and Adams, 2020). The procedures applied and fear of the spreading pathogen have had a significant impact on the everyday life of whole populations.

Particular attention should be paid to the influence of the pandemic on people’s mental health. Scientific research confirms an increase in stress levels, and rate of anxiety disorders and depression, which correlates with the COVID-19 pandemic (Babicki and Mastalerz-Migas, 2020; Luo et al., 2020; Smith et al., 2020). This is associated with both fear of contracting the disease and loneliness caused by isolation from the loved ones. The need for social bonding is deeply rooted in the human psyche, and isolation and loss of social relations can result in deteriorated cognitive function and decreased mood (Santini et al., 2020).

Observations revealed that the risk of acute symptoms and death associated with COVID-19 is higher in elderly individuals and patients with chronic comorbidities such as hypertension, heart disease or cancer, which are also more common in the elderly (Violant-Holz et al., 2020). Furthermore, a causal relationship is noted between COVID-19 transfection and the development of dementing disorders, including Alzheimer’s disease (Ciaccio et al., 2021). There is some evidence for an association of APOE ε4 (particularly ε4ε4 homozygote) with increased susceptibility to infectious disease and degeneration (Kloske and Wilcock, 2020; Ciaccio et al., 2021). It is suspected that SARS-CoV-2 infection may be a factor promoting neurodegeneration in individuals with susceptible genetic variants. Gal-3 and IL-1 proteins are also highly implicated, with increased levels of these proteins observed in patients with severe COVID-19. It has been hypothesised that increased levels of Gal-3 and IL-1 in patients with COVID-19 may also be involved in the damage leading to the development of Alzheimer’s disease (Cauchois et al., 2020; Tao et al., 2020; Ciaccio et al., 2021). Therefore, this age group is at a particularly high risk of mental disorders associated with fear of contracting COVID-19 and, at the same time, social isolation, which increases a sense of loneliness (Armitage and Nellums, 2020; Goethals et al., 2020). In addition, limitations on meeting people and recommendations to stay home lead to decreased levels of physical activity in older people, which also contributes to mental state deterioration (Goethals et al., 2020). Research confirms that social support of elderly individuals is associated with improvement in their mental health (Smith et al., 2020).

Depression is one of the most common mental diseases. The number of cases of depression is constantly increasing, particularly in the elderly (Bukhari et al., 2016; Uwabor et al., 2019). It is estimated that 20% of the world’s population of individuals aged over 65 suffer from depression; in this age group, depression may be additionally associated with neuropsychological disorders, cardiovascular diseases, diabetes or other conditions (Vilagut et al., 2016; Wilkinson and Izmeth, 2016). In the ICD-10 classification in force in Poland, the diagnostic criteria for depression include basic and additional symptoms which make it possible to diagnose and characterise the severity of depression. Basic symptoms include: lowered mood, loss of interests, decreased energy and increased tiredness. Additional symptoms include: low self-esteem and guilt, suicidal thoughts/behaviour, cognitive impairment, changes in psychomotor activity, sleep disturbances, changes in appetite associated with weight change. The diagnosis of depression requires two conditions:

The residents of long-term care institutions such as care homes (Polish: Domy Pomocy Społecznej), and care and medical treatment centres (Polish: Zakłady Opiekuńczo-Lecznicze) are at a particularly high risk of mental problems during the COVID-19 pandemic. In many such facilities special precautions were introduced for the duration of the pandemic such as limitation of or ban on family visits, restricting contacts between the residents, and sometimes even between the residents and staff. Many institutions ceased running group activities for the residents and holding communal meals. Unfortunately, research shows that individuals who stay at care centres are more commonly affected by depression compared to individuals of similar age who are not under the care of such institutions (Guimarães et al., 2019; Knyszyńska et al., 2019; Tesky et al., 2019). In addition, an increase in the level of depression and anxiety during the COVID-19 pandemic among the residents of various long-term care institutions was observed (El Haj et al., 2020; Górski et al., 2020).

Some of the main health problems among elderly individuals, which are considered to be among the most significant geriatric problems, are cognitive impairment and dementia (Han et al., 2017). These disorders develop as a result of progressing neurodegenerative changes which lead to irreversible brain damage. They are characterised by progressing memory impairment, compromised ability to think, count and write, impaired orientation in time and place, and problems with communication and language (Jia et al., 2020). Cognitive impairment and dementia are often accompanied by emotional disturbances and affective diseases (Han et al., 2017; El Haj et al., 2020). Patients’ general activity levels systematically decline and they lose their independence in daily activities. The risk of cognitive impairment increases with age; during their lifetime, 10% of people worldwide are affected. It is estimated that in 2020, approximately 50 million people suffered from neurodegenerative disorders (Jia et al., 2020). These disorders are diagnosed in approximately 3% of individuals aged between 65 and 74, in approximately 20% of people aged between 75 and 84 and in as many as nearly 50% of individuals aged over 85 (Han et al., 2017; Mazurek et al., 2018; Jia et al., 2020).

The aim of the study was to assess the risk of depression among the residents of long-term care institutions in Poland at the beginning (March 2020) and during (December 2020) the COVID-19 pandemic and to determine the relationship between the risk of depression and the occurrence of cognitive impairment in the study group.

Healthcare professionals who work at various types of geriatric facilities encounter many problems of the elderly. One of the most serious difficulties, which is observed particularly during the pandemic, is separation from family and friends. This is reflected in an increase in the rate of depressive symptoms, diagnosis of depression and the use of antidepressants (Górski et al., 2020).

The present author’s observations indicate that at the beginning of the period of ban on visits in long-term care institutions, no differences were observed between residents with neurocognitive impairment and those without it with regard to symptoms of depression. However, as the social isolation continued, the differences became more noticeable. It was observed that certain characteristic symptoms of depression occurred in high-functioning individuals, able to communicate in a meaningful way and who had been frequently visited their families before the COVID-19 pandemic.

Cognitive impairment, regardless of the cause, is typically associated with compromised memory, particularly short-term memory, and problems with abstract thinking, connecting facts and understanding cause-and-effect relationships. Advanced cognitive impairment involves problems with deeper memory stores, including long-term and autobiographical memory. One’s life history, kinship relations and relationships with friends are forgotten (Han et al., 2017; Jia et al., 2020). Paradoxically, these alarming and adverse phenomena should be considered protective against depressive symptoms in the study group.

During the study, progression of cognitive impairment was observed in a relatively large group of subjects. A particular increase was noted in the moderate dementia category (from 18.7% in March to 25.3% in December) and severe dementia (from 28.2% in March to 31.1% in December); in addition, the number of subjects with a normal MMSE score decreased (by approximately 6%). Similar relationships were found in a study by Canevelli et al. (2020). In that study, in as many as 31.7% of respondents cognitive deterioration was observed during the period covered by the study, which is a higher result than in the present study. The observations mentioned above can be the result of a natural process associated with the progression of the underlying disease. It should be noted, however, that MMSE scores decreased relatively quickly and significantly, which may be due to isolation and the associated mental illness and trauma.

As demonstrated in the present study, the risk of depression was relatively higher in individuals with a normal MMSE score or cognitive impairment without dementia than in those with various degrees of dementia. The awareness of the pandemic and the associated danger has become particularly painful to elderly individuals, who are constantly thinking about the passing of time and the approaching end of life. This is particularly relevant to the notion of acceptance of one’s old age. Normal family relations which bring much satisfaction and a sense of security to the elderly individual are key to the acceptance of slow decline in body strength, activity, loss of health and ultimately death. Unfortunately, due to the development of the pandemic, contacts with loved ones were restricted, which resulted in intensified pessimistic attitude, reluctance to leave one’s room, increased weepiness and catastrophic thinking.

The influence of the media also takes its toll. The media are an important information channel for the local, national and international community. Currently, the media reports are dominated by news on the pandemic, daily incidence rates, complications and deaths (Bilal et al., 2020; Canevelli et al., 2020). There were also reports on shortage of staff, free beds in hospitals and necessary equipment (e.g., ventilators). All of this undoubtedly had an effect on the mood of individuals from various social and age groups, particularly the elderly, who are a high-risk group due to their age. One may suspect that such information could have intensified pessimistic thinking or exacerbated anxiety disorders in the study group. Such a supposition is highly likely for individuals with no cognitive impairment who have free access to the media. Individuals with dementia are in a different situation. They have limited access to media reports and even if they do encounter some news reports, they may not understand them due to the lack of their placement in appropriate context. On the one hand, this leads to the risk of lack of information on appropriate safety measures (wearing face masks, frequent hand washing, sanitation), and on the other hand, it reduces the associated high stress (Wang et al., 2020). Similar conclusions were drawn from other studies. Bilal et al. (2020) indicated that the news policy on COVID-19 causes panic and depression. Furthermore, Yan et al. (2020) believe that the media one of the main factors affecting mental health during the COVID-19 pandemic. However, some credit should also be given to the media in the fight against the COVID-19 pandemic. As demonstrated by Zhou et al. (2020) broadcasting information on ways of infection prevention contributed to an increase in social awareness of the problem, reduced the peak of infection rates and decreased transmission at the initial stage of the pandemic.

Clinical observation of patients resulted in identifying certain characteristic features of the subjects. In elderly individuals, reluctance to leave their room, decline in general life activity, frequent inquiries about their family, sadness and concern over their health were most frequently observed. In individuals with cognitive impairment, the main observations included general anxiety and decline in independence, defined as helplessness and impaired execution of daily activities such as washing, getting dressed and eating. These data are corroborated in the literature (Brown et al., 2020; Canevelli et al., 2020). Brown et al. (2020) report that during the isolation associated with COVID-19, behavioural disorders, such as increased anxiety, psychomotor agitation, wandering and increased orientation disturbances are observed, which may result in the cessation of purposeful activity. Similar findings were presented in the study by Rainero et al. (2021), which is the largest study on the relationship between pandemic COVID-19 and dementia patients. It proved that cognitive and behavioural deterioration was observed in more than half of the patients. It was noted that quarantine exposure was associated with an acute worsening of clinical symptoms in patients with dementia, as well as an increased burden on caregivers (Rainero et al., 2021). It is also important to note the interrelationship between cognitive function decline and depression. Yoon et al. (2017) demonstrated that patients diagnosed with depression showed worse cognitive functioning than patients without depression. Moreover, the introduction of depression treatment was associated with improvement or prevention of cognitive decline. Similar relationships were noted in the study by Anderson et al. (2020). It proved that when depression was remitted, patients’ functioning improved in some components of cognitive functioning, e.g., self-memory, autobiographical memory or category verbal fluency.

However, special attention should be paid to the study by Donovan et al. (2017). The cited study examined 8382 respondents over the age of 65 years. It evaluated the mutual influence of factors such as, loneliness, cognitive functioning and depression. The authors demonstrated that loneliness significantly influenced cognitive decline regardless of socio-demographic factors, social network, poor health and baseline depression. Our own results appear to support these findings. Social isolation caused by the development of the COVID-19 pandemic increased the prevalence of depressive symptoms and exacerbated cognitive deficits. The reciprocal effect of depression on cognitive functioning and, conversely, of cognitive functioning on depression remains undisputed, but we suspect that in our study, as in the Donovan study (Donovan et al., 2017), social isolation and loneliness are the main factors affecting both.

The impact of the COVID-19 pandemic has been vigorously discussed in the Polish and international community of psychologists, psychiatrists, geriatric psychologists, geriatricians and gerontologists. Clinicians notice certain differences in the functioning of individuals with and without cognitive impairment during the pandemic; however, to date, no study has been found that would demonstrate the existence of such differences in a scientific manner. This study is intended to fill this gap at least to a small extent. This is not a perfect study and we are aware of certain limitations. The drawbacks of this study is the fact that no standardised questionnaire has been used. The choice of a non-standardised questionnaire was based on the fact that none of the widely available standardised questionnaires makes it possible to conduct such a study in individuals with cognitive impairment. Tests such as the Geriatric Depression Scale (GDS) or Beck Depression Inventory (BDI), require self-awareness and appropriate critical approach to one’s feeling, behaviour, attitudes and health status, which are lost in individuals affected by cognitive impairment. Moreover, depression in elderly individuals are often masked with other symptoms than sadness; for this reason, particular emphasis was placed in the study on behaviour that is possible to asses by the staff, not just emotions and feelings of the patient (Guimarães et al., 2019; El Haj et al., 2020). The study group was a population of patients residing at long-term care institutions in, which made it impossible to select the group in terms of the number of patients with and without depression according to the duration of the pandemic. The lack of statistical significance in the first study period (March) may be related to the too small group of residents with depression. This fact should be considered a limitation of the study. A simplified correlation between MMSE scores and “Depressive Symptom Inventory” was used in this research. Selected confounding criteria such as, education level, comorbidities, functional or physical activity level were not considered, which requires additional analyses in the future and is a limitation of this study.

In conclusion, a higher risk of depression was observed with the development of the pandemic. At the initial stage of the COVID-19 pandemic (March) the risk was assessed as low and in the second stage of the study (December), the risk significantly increased. Residents with cognitive impairment are characterised by a lower risk of depression compared to individuals with a normal MMSE score. It is believed that the reason for this is prolonged period of isolation, which had an adverse effect on the mental state of the participants who had a high level of functioning before the COVID-19 pandemic. The pandemic also affected MMSE scores. In the course of the study, progression of cognitive impairment was observed in the residents, apart form that, the proportion of subjects with a normal MMSE score decreased. What is more, the results of the present study show that the awareness of danger plays and important role in coping with the COVID-19 pandemic. Factors such as isolation, sense of lack of security, stress, pessimistic thoughts and general decrease in mood may result in the development of depression and cognitive impairment.

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

MGó led the conception of work and analyses, as well as the interpretation of data for publication and the writing of the manuscript. JG, MGr, BC, KP, and AG contributed to the design and the writing of the manuscript, namely preparation and critical revision. MB supervised the analyses. RP was the primary reviewer of the manuscript and contributed many of the final revisions. All authors have read and approved the final version for publication and contributed to the article and approved the submitted version.

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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