**1. Introduction**

In 2020, Poland was forced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic to introduce its first-ever national lockdown. The disease, commonly referred to as Coronavirus Disease 2019 (COVID-19), was first observed at the end of 2019, while the first case of infection in Poland was recorded on 4 March 2020. A much more infectious SARS, and with a higher mortality rate than influenza, COVID-19 has resulted in more than 84 million confirmed cases and 1.8 million deaths worldwide [1]. In Poland, novel coronavirus has killed almost 28,000 people and more than 1.3 million have been infected.

During previous coronaviral epidemics, such as SARS and Middle East respiratory syndrome (MERS), symptoms were more severe in people with chronic diseases and were often associated with a poor prognosis [2]. The Centers for Disease Control and Prevention (CDC) continually updates the list of conditions that increase the risk of undergoing a severe course of COVID-19. This list is not definitive and currently only includes conditions for which there is adequate clinical evidence. It allows clinicians to identify the most at-risk groups of patients for individualized prevention, treatment or care strategies. Chronic diseases listed by the CDC as those that can lead to a severe course of COVID-19 include cancer, chronic kidney disease, chronic obstructive pulmonary disease, Down's syndrome, heart disease such as heart failure, coronary artery disease or cardiomyopathy, obesity, sickle cell anemia, smoking, diabetes, immune-weakening conditions due to blood or bone

**Citation:** Wa ´nkowicz, P.; Szyli ´nska, A.; Rotter, I. The Impact of the COVID-19 Pandemic on Psychological Health and Insomnia among People with Chronic Diseases. *J. Clin. Med.* **2021**, *10*, 1206. https://doi.org/10.3390/ jcm10061206

Academic Editor: Michele Roccella

Received: 26 January 2021 Accepted: 12 March 2021 Published: 14 March 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

marrow transplantation, immune deficiencies such as in human immunodeficiency virus (HIV) and the use of corticosteroids or other immune-weakening drugs e.g., those for autoimmune diseases [3]. Autoimmune diseases, apart from cardiovascular diseases and cancer, are an increasing problem for the Western world. However, their exact causes are largely unknown and, moreover, are difficult to identify at the preclinical stage. It is likely that for this reason, they are not the most attractive topic for research in many countries, including Poland. Associated with abnormal functioning of the immune system, autoimmune diseases involve an undirected response against the body's own organs, tissues and cells [4]. Currently, more than 20 million people suffer from autoimmune diseases in the United States alone, while epidemiological data provide evidence of a steady increase in their incidence in Western societies over the past few decades. Incidence rates of autoimmune diseases vary from less than 5 per 100,000 for uveitis to over 350 per 100,000 for Hashimoto's disease [5]. Hashimoto's disease is one of the most common autoimmune diseases in the population. It is difficult to diagnose and diagnosis often occurs in the later stages of the disease. The most common biochemical abnormalities in Hashimoto's disease are elevated levels of thyrotropic hormone and low levels of free thyroxine combined with increased levels of antithyroid peroxidase antibodies. However, in the early stages of the disease, patients may be asymptomatic and biochemical test results may be normal which is associated with the periodic destruction of gland cells in this phase. This disease is most likely to affect young, active women [6]. Knowledge regarding autoimmune diseases appears to have a key role in the era of COVID-19. As the COVID-19 pandemic has progressed, there have been various reports on the development of autoimmune diseases in individuals infected with SARS-CoV-2. The mere entry of the SARS-CoV-2 virus into respiratory epithelial cells induces a severe inflammatory state known as a cytokine storm in some patients. Symptoms associated with autoimmune diseases such as fatigue, joint pain, muscle aches, and brain fog may appear during SARS-CoV-2 infection and persist even after infection. As well as this, autoimmune phenomena are supported by the presence of antinuclear antibodies, anti-DNA, or complement consumption in these patients [7]. In a study conducted by Bastard et al., it was observed that at least 101 of 987 patients with a life-threatening course of COVID-19 had neutralizing immunoglobulin G autoantibodies against interferon-ω, against interferon-α, or against both in the early stages of COVID-19. Several patients also had autoantibodies against the other three type I interferons [8].

The SARS-CoV-2 pandemic has seriously affected many aspect of human life and has dramatically threatened the mental and physical health of the general public. Ubiquitous information in the mass media about its high infectivity, mortality, diseases predisposing to the adverse course of SARS-CoV-2 infection, as well as social isolation, lack of targeted treatment, and limited access to medical care produce a huge mental burden which results in psychological distress and sleep disorders [9–13]. Patients with chronic conditions experience higher stress levels due to being at higher risk for worse outcome from COVID-19 [14]. In an analysis conducted by Addis et al., it was noted that older age, female sex, longer duration of illness, presence of respiratory symptoms and no social support were significantly associated with an abnormal psychological impact of COVID-19 on patients with chronic disease [15]. However, the analyses of mental health disorders refer mainly to health professionals, and rarely to people with chronic diseases [16]. To the best of our knowledge, until now, there has been no study on the psychological impact of COVID-19 among patients with chronic disease in Poland. Therefore, this study represents the first psychological impact of COVID-19 among high-risk groups, chronic disease patients in the West Pomerania region in Poland. Thus, this study aimed to assess the symptoms of insomnia, depression and anxiety, among people with chronic diseases during the COVID-19 pandemic in Zachodniopomorskie province in Poland. The result of our study may help the governmental and medical community in formulating comprehensive interventions to prevent psychological problems of chronic disease clients related to COVID-19.
