On May 5, 2023, following a three-year-long pandemic, the World Health Organization officially announced an end to the global emergency caused by coronavirus disease 2019 (COVID-19). From early 2023, the newly reported severe acute respiratory syndrome-coronavirus-2 cases started exhibiting a sustained and relatively stable pattern [1], and the South Korean government downgraded the COVID-19 crisis alert level from “serious” to “warning” on June 1, 2023. Despite the reduced medical threat of COVID-19, the long-lasting repercussions of this viral outbreak persist. Over 770 million COVID-19 cases have been confirmed, with nearly 7 million fatalities as of September 2023 [2]. The extensive spread of disease and the consequential imposition of restrictions on various activities have had adverse effects, particularly on the mental health of individuals. Globally, the prevalence of depression and anxiety symptoms in the normal population increased significantly [3]. More than 23% of healthcare workers presented with anxiety and depression [4], and children and adolescents experienced psychological problems due to the activity restrictions [5].

Illness anxiety disorder (previously referred to as hypochondriasis) is defined as being preoccupied with health status and fearful about acquiring a disease. The development of illness anxiety disorder can be explained by a model of a cognitive-behavioral vicious cycle, starting with the fear of being sick inducing anxiety. Consequently, one may either start to avoid problems or seek reassurance [6]. Reassurance-seeking can provide temporary relief, but it eventually ends up with stronger feelings of fear and preoccupation with the illness [7]. Therefore, reassurance-seeking behavior can be a good indicator of illness preoccupation.

This reassurance-preoccupation behavior includes repeated checks on bodily sensations, hand hygiene, and extensive online health-related searches during the COVID-19 pandemic. As the fear of being infected develops, an individual move on to reassurance-seeking behaviors, which paradoxically worsen the anxiety. During the pandemic, a reassurance-seeking behavior among medical students mediated an effect of viral anxiety and depression on obsession with COVID-19 [8]. This phenomenon is more prominent in this era of information overload, as cyberchondria involves using the internet owing to increased levels of health distress [9]. An analysis of the spread of information on five of the biggest online platforms revealed that the infodemic was caused in regions where the news media was less regulated, and the news from unreliable sources spread quickly [10]. Research showed that social media exposure was positively correlated with mental disorders [11,12]. This interferes with the social measures taken against the spread of infection and affects individual’s preoccupation with well-being.

For patients who were infected with COVID-19, this mechanism was more apparent. Approximately 8 to 10 months after acute infection, 10.4% of the COVID-19 infected patients met the criteria for somatic symptom disorder, characterized by extreme anxiety about physical symptoms [13]. Predictably, psychological symptoms, including anxiety and depression, were more common in patients infected with COVID-19 [14]. According to a survey in China, 96.2% of the quarantined patients suffered from posttraumatic stress symptoms [15]. Meta-analysis of the online biomedical databases showed that mental health problems were common, especially in infected cases during a pandemic. Of the COVID-19 patients, 41.7% reported depression, and 42.3% reported anxiety [16]. It is plausible that this unstable status initiates the cycle of illness anxiety disorder, placing considerable mental stress on the affected individuals.

In such stressful situations, the concept of dysfunctional self-focus has been reported. Self-focus refers to a phenomenon or state in which an individual’s attention turns to oneself. The role of self-focus can be largely divided into functional and dysfunctional aspects [17]. The dysfunctional aspect of self-focus is distinct from rumination. Rumination is a response style that continues to recall the cause of negative emotions or unresolved past problems, whereas self-focus starts from self-consciousness and is a cognitive process necessary for inner perception and reflection. However, in some instances, dysfunctional self-focus and rumination can be similar [18]. Dysfunctional self-focus can worsen the psychological stress associated with stressful situations [19]. Thus, dysfunctional self-focus can increase depression [20] because self-focus can be maladaptive in depression [21].

In this study, we explored the feasibility of applying a cognitive-behavioral model of hypochondriasis in COVID-19-related infected cases. In addition, we examined whether the dysfunctional self-focus contributes to the COVID-related model of hypochondriasis. We hypothesized that 1) coronavirus reassurance-seeking behaviors in infected individuals were positively correlated with their preoccupation with coronavirus, 2) viral anxiety of infected cases was positively associated with their preoccupation with coronavirus, 3) dysfunctional self-focus of infected cases was positively related to their preoccupation with coronavirus, 4) dysfunctional self-focus influenced the cognitive-behavioral model of COVID-related hypochondriasis.

Data from 265 participants who had COVID-19 infection were collected (Table 1). Their mean age was 39.6±10.5, 158 (59.6%) were female, and 106 (40.0%) had a relationship status of being single. Among these participants, 13 (4.9%) had been infected twice, 250 (94.3%) were vaccinated, 38 (14.3%) had a past psychiatric history, and 33 (12.5%) had current psychiatric distress.

Pearson’s correlation analysis is shown in Table 2, and the OCS score was significantly correlated with CRBS (r=0.75, p<0.01), SAVE-6 (r=0.48, p<0.01), PHQ-2 (r=0.52, p<0.01), and DSAS (r=0.28, p<0.01). The DSAS score was significantly correlated with the CRBS (r=0.28, p<0.01), SAVE-6 (r=0.23, p<0.01), and PHQ-2 (r=0.31, p<0.01). Linear regression analysis revealed that the OCS score was associated with CRBS (β=0.60, p<0.001), SAVE-6 (β=0.20, p=0.007), and PHQ-2 (β=0.13, p<0.001), F=85.6, p<0.001 (Table 3).

Mediation analysis showed that viral anxiety directly influenced COVID-19 preoccupation among infected cases, and coronavirus reassurance-seeking behavior mediated this relationship (Table 4). It fortified the feasibility of the application of cognitive-behavioral model hypochondriasis in individuals infected with COVID-19. We also observed that dysfunctional self-focus did not directly influence COVID-19 preoccupation. However, the relationship was mediated by viral anxiety, coronavirus-related reassurance-seeking behavior, and depression (Table 5 and Figure 1).

In this study, we showed that individuals with COVID-19 who had preoccupied thoughts about the infection had viral anxiety, depression, and coronavirus-related reassurance-seeking behavior. We found that a hypochondriasis cognitive-behavioral model is feasible for applying in individuals infected with COVID-19. Furthermore, viral anxiety, coronavirus-related reassurance-seeking behavior, and depression mediated the influence of dysfunctional self-focus on preoccupation with COVID-19.

Previously, we demonstrated that the cognitive-behavioral model of COVID-19-related hypochondriasis can be implemented across diverse groups. A study involving medical students revealed a noteworthy association between viral anxiety and preoccupation with COVID-19, and reassurance-seeking behavior was identified as a mediating factor [8]. This association was prominent among healthcare workers who had encountered a high number of patient deaths, leading to subsequent rumination [33]. Furthermore, previous studies have affirmed the relevance of this model within the broader general population [34]. In this study, we examined the feasibility of the cognitive-behavioral model of COVID-related health anxiety among individuals from the general population infected with COVID-19. Using mediation analysis, we confirmed that this model is applicable to infected individuals. We anticipate that this model will serve as a foundation for comprehending health anxiety related to the virus in the general population in the event of future pandemics.

We also found a significant association between dysfunctional self-focus and preoccupation with the virus. However, the mediation analysis results showed that dysfunctional self-focus did not exert a direct influence on preoccupation with COVID-19. Dysfunctional self-focus is characterized by a lack of ability to regulate attention, oscillating between past, present, and future events, with unclear focus targets. Additionally, the attention is diverted towards negative thought patterns. Despite hierarchical differences, dysfunctional states of self-focus and rumination are often considered analogous, leading to the term ‘ruminative function of self-focus [18]. Contrary to the misconception that ruminative thinking aids problem-solving [35], it has been shown that ruminant thinking is a determinant of stress in response to negative events [19]. Rumination triggers negative emotional states, perpetuating a vicious cycle of increased rumination [36]. Dysfunctional self-focus is known to exacerbate mood, depression, and anxiety [37], particularly demonstrating associations with obsessive-compulsive disorder and somatization [38].

Nonetheless, dysfunctional self-focus did not directly impact individuals who tested positive for the virus; several factors may contribute to this observation. A confirmed diagnosis of COVID-19 might lead to a reduction in anxiety and preoccupation related to the virus. The initial fear during the early stages of the pandemic, when COVID-19 diagnosis was considered potentially fatal, could have diminished over time. Postinfection, individuals may have developed a sense of reassurance, given the understanding that after experiencing an initial discomfort, they were likely to develop immunity and be less prone to re-infection. Several studies have indicated significantly lower levels of anxiety, depression and mental illness among individuals who had received the vaccine compared to non-vaccinated individuals [39]. Previous studies suggesting that groups with a history of COVID-19 infection were less inclined to adhere to preventative measures may stem from this underlying perception [40].

Another possible explanation is that people may have become more accustomed to viral infections with time. Additionally, as virus variants emerged and fatality rates decreased, dysfunctional self-focus could reduce the attention on virus preoccupation. These observations indicate that dysfunctional self-focus may not directly influence virus preoccupation among COVID-19-infected individuals, highlighting the evolving perceptions and experiences that individuals experience over the pandemic.

However, this relationship between dysfunctional self-focus and virus preoccupation demonstrated meaningful associations when integrated with the cognitive-behavioral model. The model was significantly associated with the mediation of virus anxiety responses and reassurance-seeking behaviors. In other words, while dysfunctional self-focus may not directly influence the preoccupation itself, it could potentially lead to an obsessive preoccupation with the disease depending on the anxiety responses and reassurance-seeking behavior. When the infection risk is low, individuals exhibit higher psychological resilience scores [41], and perceived epidemic risk and psychological symptoms are positively correlated [42]. Similar to these findings, a study conducted in the UK revealed a decrease in mental health problems after September 2021.

In the current study, depression mediated the relationship between dysfunctional self-focus and preoccupation with COVID-19. Dysfunctional self-focus (also known as ruminative self-focus) can trigger depression. Ruminative responses predict depressive disorders, the onset of new depressive episodes, and the prolonged duration of depressive symptoms [43]. Moreover, laboratory investigations have confirmed that induced rumination heightens ruminative self-focus, resulting in a detrimental impact on mood in depressed patients [44]. Several experimental ambulatory assessment studies have consistently reported that this effect extends into individuals’ daily lives [37]. Furthermore, various studies have indicated an association between depression and preoccupation. The severity of depression is notably linked to elevated scores on delusion items, including hypochondriasis [45]. Additionally, there is an observed heightened vulnerability to hypochondriasis in older individuals with depression [46]. This association was observed even in relation to COVID-19 [8]. Though no previous study has explored this relationship among infected individuals, we demonstrated that depression in infected individuals with COVID-19 might underlie dysfunctional self-focus and preoccupation when infected.

There are several limitations of this study. First, we collected responses from the general population who had been infected with coronavirus. However, they were not seriously ill or hospitalized. The results need to be interpreted with caution in severely infected patients who require medical attention. Second, this study was conducted in December 2022, three years after the first coronavirus outbreak in South Korea, making it possible that people could have adjusted to the viral pandemic situation and think they would be safe from re-infection. However, the worry of people in Korea over the big surge in infected cases in China in December 2022 [47] needs to be considered when interpreting the results of this study. Third, this study was conducted via an online survey, and we could not conduct the polymerase chain reaction test. Hence, we cannot confirm whether all participants had really been infected with coronavirus. Finally, participants’ psychological symptoms were assessed using subjective rating scales instead of objective measures or face-to-face interviews with psychiatrists. Responses to subjective measurement may lead to bias or inaccuracies. When interpreting participants’ responses, it should be taken into account.

In conclusion, our study reveals that preoccupation with coronavirus is significantly influenced by viral anxiety, depression, and reassurance-seeking behavior among individuals who were infected with the COVID-19 infection. The cognitive-behavioral model of hypochondriasis was found to be applicable in this context, emphasizing the interconnectedness of dysfunctional self-focus. These findings underscore the importance of tailored psychological support for individuals recovering from COVID-19. Educational programs and comprehensive mental health screening are crucial components of public health efforts, which can be aimed at enhancing awareness and addressing emotional responses effectively. Integrating mental health considerations into a broader healthcare system can lead to a more comprehensive approach to managing the unique psychological challenges associated with the pandemic.