High prevalence of psychiatric disorders in pandemics has been reported in several studies. A study of severe acute respiratory syndrome (SARS) is about significant rates of psychiatric morbidity related to SARS [3]. Approximately 75% of participants changed their behavior because of fear of infection, and some of them also showed emotional distress in the H1N1 epidemic [4]. People not diagnosed with Middle East respiratory syndrome (MERS), but isolated, experienced anxiety in 7.6% of cases and anger in 16.6% of cases [5]. Even in the COVID-19 pandemic, these psychiatric-related problems were observed. According to a study with more than 2000 participants during the COVID-19 pandemic, anxiety is prevalent in about 34% of the population [6]. Systematic review and meta-analysis studies of COVID-19 pandemic populations revealed that anxiety and depression are common among more than 30% of those affected [7]. Also, COVID-19 is associated with depression severity in the general population [8].

Fear of contamination and excessive checking are the symptoms most frequently associated with COVID-19 [9-11]. Additionally, those who wear masks and wash their hands are significantly more likely to fear contamination, as their characteristics correlate with behaviors that reduce the spread of infection. The model of hypochondriasis (currently known as Illness Anxiety Disorder) states that fear of being sick leads to anxiety, which leads one to avoid the problem or seek reassurance [12]. An illness anxiety cognitive-behavioral model suggests that when someone is anxious about getting ill, they try to avoid the problem or seek reassurance. Getting immediate relief from reassurance strengthened one’s original fear, which will contribute to preoccupation with the illness. It will cause preoccupation with the illness if this process continues.

In this COVID-19 pandemic, if one is afraid of being infected in this COVID-19 pandemic, then one may engage in reassurance-seeking behavior, such as checking bodily sensation, maintaining hand hygiene, or reading repeated media articles [13]. Recurrently engaging in reassurance-seeking behaviors may paradoxically increase anxiety. When people are worried about their health or feel anxious about it in some way, they seek reassurance, which can be a sign of preoccupation with COVID-19 viral infection. We all experience some degree of health anxiety at some point in our lives, and these behaviors can help us identify and protect against illnesses in the early stages. Recurrent engagement in reassurance-seeking behaviors, however, increases anxiety [14]. Excessive consumption of media and distress are often related to anxiety and uncertainty, creating a cycle that is difficult to break. People with high health anxiety must constantly seek reassurance, which can result in them resorting to reassurance-seeking behavior [15].

A number of studies were conducted which explored the relationship between viral anxiety, feelings provoked by worries about exposure to virus and infection and insomnia during the COVID-19 pandemic. It is well known that insomnia symptoms were associated with depression or anxiety [7]. In COVID-19 pandemic, a study found that viral anxiety was a consistent predictor of insomnia [16]. Stress, anxiety, and depression may be more likely to occur in individuals suffering from pre-existing and post-pandemic insomnia during the COVID-19 pandemic [17]. And, those who are uncertain as to whether they will contract COVID-19 and fear direct contact with COVID-19 infected individuals are at greater risk for sleep disturbances [18]. University students who fear catching COVID-19 significantly experienced higher levels of anxiety or insomnia [19], and dysfunctional beliefs about sleep of cancer patients mediated the effects of anxiety on functional impairment [20]. Among healthcare workers, insomnia mediates the effects of viral epidemics on anxiety and depression [21]. However, it has not yet been studied empirically on the relationship between insomnia and coronavirus reassurance-seeking behavior, though it has been reported that obsessive compulsive symptoms may increase in those with insomnia symptoms before the coronavirus pandemic [22]. Because of the connection between sleep disorders and anxiety, as well as high-risk factors that make humans particularly susceptible to viral infections during this pandemic [23], it is important to understand the mediating effect of insomnia on the enhancement mechanism of anxiety symptoms.

In this study we aimed to explore whether insomnia, viral anxiety, reassurance-seeking behavior, and preoccupation with COVID-19 are related among the general population in this study. In addition, we tried to explore whether insomnia may mediate the viral anxiety and preoccupation with COVID-19. We hypothesized that 1) reassurance-seeking behavior will be positively related to preoccupation with COVID-19, 2) viral anxiety will be positively associated with preoccupation with COVID-19, 3) insomnia will be positively associated with preoccupation with COVID-19, and 4) insomnia will at least partially mediate the relationships between reassurance-seeking behavior and preoccupation with COVID-19 among the general population.

The mean and standard deviation of participants’ demographic characteristics and rating scale scores are summarized. Two-tailed significance was determined by a p value of 0.05. Correlation analysis was performed using Pearson’s correlation coefficient. We used linear regression to examine which variables can predict obsession with COVID-19. The bootstrap method with 2000 resamples was implemented to determine whether insomnia mediates the influence of viral anxiety or reassurance seeking behavior on preoccupation with COVID-19. The SPSS version 21.0 (IBM Co., Armonk, NY, USA) was used to conduct the general statistical analysis, and AMOS version 27 (IBM Co.) and Jamovi ver 1.6.23 (The jamovi project, Sydney, NSW, Australia) were used to conduct the mediation analysis.

Preoccupation with COVID-19 virus was associated with younger age, insomnia, viral anxiety, and reassurance-seeking behavior in this study. Vicious cycle among viral anxiety, reassurance-seeking, and preoccupation with COVID-19 was already reported. We reported previously that the reassurance seeking behavior of healthcare workers and their preoccupation with COVID-19 were associated with work-related stress and viral anxiety of healthcare workers [32]. In addition, among medical students, preoccupation with COVID-19 was reported to be predicted by viral anxiety and reassurance-seeking behavior [32], similarly to the results of the current study. Having anxiety about viral infection is beneficial to protect from infection, but excessive anxiety and obsessive thinking can be detrimental to mental health. Since this COVID-19 pandemic has lasted for a long time, persistent anxiety and obsessional thoughts should be managed. When people feel anxious, they may seek assurance to reduce their anxiety and risk of harm. Therefore, they may engage in reassurance-seeking behaviors such as checking their body temperature, repeating hand washing, or monitoring their physical symptoms. In the short-term, reassurance-seeking behavior may reduce anxiety briefly, but in the long run, it may strengthen the tendency to seek reassurance. Although it is not always easy to distinguish repeated handwashing as a reassurance-seeking behavior from a preventive measure, hypochondriacal fears may trigger reassurance-seeking behaviors [33]. In addition, cyberchondria, which is an excessive online health search associated with higher levels of anxiety and reassurance-seeking behavior, is made worse by repetitive, misleading information that is spread on social media.

Age and preoccupation with COVID-19 are inversely correlated, and this relationship is complicated. Having an underlying medical condition and old age were risk factors for COVID-19 infection [34]. As a result, the older are likely to be aware of their vulnerability to infection. The result may be a stabilized cautious lifestyle regardless of other informative influences. In contrast, young people can easily access the information of COVID-19 via the internet, and they are more likely to seek reassurance repeatedly. These points need to be explored in the further study.

In this study, we observed that reassurance-seeking behavior and viral anxiety were predicting variables for preoccupation with COVID-19. And also, we observed that insomnia can be a mediator on this vicious cycle model of hypochondriacal preoccupation. In this COVID-19, high prevalence of insomnia was reported. Approximately 38% of participants in Greek population-based study reported that sleep problems [35]. Other two studies covering general population associated with COVID-19 also showed that higher prevalence of sleep disturbance each about 19% and 13% of participants [36,37]. Sleep disturbances are known to be associated with the weakened immune system, and a weakened immune system increases the risk of viral infection [38]. If they cannot sleep well, people may worry about getting infected with a virus as a dysfunctional belief about sleep. Consequently, insomnia can increase an individual’s anxiety levels [39]. In other words, insomnia exacerbates anxiety and concerns about viral infections. As a consequence, there is an increase in reassurance seeking behaviors like fever checking, symptom evaluation, and internet browsing, and as insomnia persists, reassurance seeking behaviors increase, and people become obsessed with COVID-19 information. Our study provides significant insight by revealing that insomnia mediates this process.

This study has some limitations. First, the online survey design has the potential to cause bias. In order to prevent the spread of the virus during this pandemic era, we decided to conduct an online survey rather than a face-to-face interview. However, the responses may not be as reliable as they seem. Second, the result of a small sample size cannot be applied to the entire population. The sample we collected included similar allocation by sex, age group, and entire area of Korea, and we could improve the representativeness of the sample. Third, Since COVID-19, viral anxiety, reassurance seeking, and insomnia are related to anxiety, there needs to be caution when explaining their connection. Moreover, there could be confounders not considered in this study, such as occupation, education level, or social economic status, that might affect the results. Lastly, the study took place from November 9–15, 2021. The Korean government started implementing the “living with Coronavirus” policy starting November 1st, 2021, and soon the number of confirmed cases exceeded 7000 per day. Although the rapid spread of the virus may affect these results, we should also take into account the fact at the same time that people have already become used to 2 years of pandemic.

In conclusion, we observed that insomnia partially mediated the vicious cycle of the hypochondriacal preoccupation with COVID-19 linked to reassurance seeking-behavior and viral anxiety. Sleep specialists should address the insomnia symptoms of people in order to reduce viral anxiety and repetitive reassurance-seeking behavior that can contribute to the preoccupation with COVID-19.