Sadness, counseling for sadness, and sleep time and COVID-19 pandemic in South Korea: Rapid review and a post-hoc analysis

We used the data from the 2009-2021 Korea Community Health Survey (KCHS) conducted by the Korea Disease Control and Prevention Agency (KDCA). The baseline characteristics, body measurements, and health-related data including depression status and average sleep time of adults 19 years or older living in South Korea between 2009 and 2019 were obtained via interview. Data were obtained from throughout Korea based on the region of residence, having an average sample size of 900 people per each community health center (total 235 centers)[11].

Of the 2,976,925 total participants, participants with incomplete height and weight information (n=103,010), incomplete body-mass index information (n=489), and incomplete average sleep time data (n=995) were excluded from this study. The Kyung Hee University (KHUH 2022-06-042) and the KDCA approved the study protocol. This study was conducted in accordance with the principles of the Declaration of Helsinki and all participants signed a written informed consent form

Continuous variables used in this study were age, body mass index (BMI, kg/m²), monthly household income and average sleep time. Categorical variables used were sex, educational background, region of residence, alcohol consumption, smoking status, occupation group, and marital status. The study stratified and included the specific variables as follows: age (19 to 39, 40 to 59, and ≥60 years), monthly household income (less than 3 million won, 3 million won or more, unknown; 3 million won is equivalent to about 2,200 US dollars), region of residence (urban areas [Seoul, Gyeonggi, Incheon, Daejeon, Sejong, Gwangju, Ulsan, Daegu, and Busan] and rural areas [Gangwon, Chungbuk, Chungnam, Jeonbuk, Jeonnam, Gyeongbuk, Gyeongnam, and Jeju]) [12, 13], alcohol consumption (0, 1-4, and 5-30 days/month), BMI group (underweight or normal [<23.0 kg/m²], overweight or obese [≥23.0 kg/m²]), education background (high school or less, and college or more), and occupational group (white-collar, blue-collar, and unknown).

We combined and defined two or three consecutive years (2009 to 2011, 2012 to 2014, 2015 to 2017, 2018 to 2019 and 2020 to 2021) to stabilize each estimate with a 95% confidence interval (CI). Subgroup analysis was performed separately by income, current smoking status, alcohol consumption, BMI group, education background, occupational group, and marital status. Statistical analyses were performed using the SPSS software (version 26; IBM Corp, Armonk, NY, USA). A two-sided p value <0.05 was considered statistically significant.

In contrast to the periods before the pandemic, the prevalence of sadness symptoms, counseling for sadness, and the average time of sleep among adults during the pandemic increased, decreased and increased, respectively. Rates of change were significant in all groups for the trend of counseling for sadness and average sleep time. For sadness, prevalence was shown to have increased significantly especially for the non-smoking and married populations. Finally, the pandemic increased the disparities in depression across smoking status, alcohol consumption, marriage, vigorous physical activity, and income groups.

Since the three variables, especially the average sleep time and sadness status of an individual are known to be closely related, this study aimed to find the change in trends of the variables in a nationwide scale. The COVID-19 pandemic has altered the sleep patterns and mental health of people globally. Sleep problems including reduced sleep time and high levels of psychological distress such as depression and anxiety have been observed in several studies during the COVID-19 pandemic [14, 15]. Findings in this study suggest the average sleep time and sadness among adults both have increased during the pandemic period, and the changes are closely related.

There are other studies that have also used the KCHS data to compare the status of depression and sleep time of adults before and after COVID-19 [16, 17]. However, these studies made comparisons simply between 2019 and 2020 or investigated measures of 2020 only, and could not determine whether the changes were due to the COVID-19 pandemic or simply a fluctuation of rates as continuations of previous trends. By observing from 2009 to the mid/early pandemic, we were able to determine and clarify the direction and changes in trend through a prolonged period. The KCHS is a large-scale database which report the health-related results and lifestyle characteristics of adults by administering the survey to individuals across all country regions. The database is unique in that it collects various health data continuously and annually since the survey started in 2008. Unlike other related studies[18], this study was able to investigate depression and sleep related trends on a large scale from 2009 to 2021.

The increase trend in the prevalence of sadness during the pandemic was clear among most of the populations. The increase of depression (or sadness) during the pandemic can have several mechanisms. First, in response to the COVID-19 pandemic, governments around the world encouraged and requested social distancing, closures of specific businesses, schools and public space, and banned large gatherings in such areas. This led to the decrease in social encounters and meetings, eventually to the isolation of members in vulnerable populations[19]. Social isolation and loneliness are known to be closely related with mental health problems including depression [20]. Also, inadequate accessibility to resources, frustration, and boredom during quarantines might have led to mental health problems [21]. Furthermore, the concerns and fear of COVID-19 infection might have contributed to symptoms of depression amongst populations. Those who were infected experienced discrimination and isolation as well as the symptoms of disease, and those who were not infected experienced worry in relation to infection[22]. Citizens were warned of the pandemic through massive information via social media which exacerbated the fear[23]. Importantly, literature suggests that fear of infection lead to an increase in depressive symptoms[24]. Global socioeconomic crisis, general changes in culture and politics, and inaccessibility to medical services are other possible factors contributing to the result[25].

Counseling is an important means to decrease anxiety and depression among patients[26]. People who received counseling for depression have decreased in percent changes, even though depression has increased in rate in our findings. Elaborating, the ascending slope of depression exceeds that of counseling for depression entering the COVID-19 pandemic. This brings concern that those who gained depression during the pandemic did not or could not achieve appropriate counseling for such symptoms. A plausible reason for such results may be the lockdown and social-distancing policies, and the following reduced accessibility to medical services during the pandemic. Accessibility to healthcare including mental health have reduced in significant manners during the pandemic [27]. Also, the concern for infection led people to stay home, decreasing the willingness to get counseling for depression[28, 29]. Unmet needs for mental health services caused serious impact on vulnerable populations and those who had mental disorder from before.

Interestingly, average sleep time of adults increased than expected during the COVID-19 pandemic. Considering the pandemic has brought lockdown for prolonged periods, staying indoors, reduced physical activity, and reduced sunlight exposure, are likely to have increased the average time of sleep of individuals[30]. A report suggests the lack of social zeitgebers during the pandemic might be a reason[31]. People lost regular work schedules and social activities, which were defining generally the sleep time of the active population. The least percentage change in sleep time for the elderly (above 60 years old) among the age group supports the mechanism, in our study.

Governments must provide a system for adequate mental health services. To note psychiatry consultations might be less accessible, interventions such as digital mental health service is required[32]. Health professionals should consider individualized precision medicine, taking into account vulnerable populations such as women, low-income individuals, and those with lower levels of education[33]. Also, diagnosis and treatment of depression, as well as the monitoring of psycho-physiological well-being including sleep time of patients amid the pandemic should be taken into public concern.

However, large-scale studies regarding the variables have been used in self-reported questionnaires generally. This study is a nationwide study, showing status of people living in South Korea. The findings of our study should be replicated in countries other than Korea[34]. The findings of our study and the plausible mechanism discussed above must be assessed in further studies internationally. Since the study includes large-scale survey, however, the findings will gain scientific importance if results attain reproducibility. Also, it is possible that the changes of variables entering the pandemic were simply a fluctuating trend. However, numerous other related studies investigating the trends in large-scale supports that the present[35]. Lastly, the differences in stance of restriction and quarantine policies between nations must be considered to discuss further values of such findings.