As COVID-19 spreads worldwide, increasing attention has been paid to the need for international comparisons to inform the global response.¹ However, there have been few comparisons across countries using analogous measures. This has important implications. First, predictors of the mental health toll of the virus are not readily comparable. Psychological support may need to be provided to different population segments in different societies. During the outbreak of SARS, quarantine was associated with increased psychological distress,² but this has not been assessed cross-nationally. Second, previous work on pandemics suggests an association with anxiety and adherence to recommended social distancing,³ as well as other more contested behaviours, such as the use of vitamins and traditional medicines.⁴ However, a lack of cross-national comparisons means that associations between mental health and these behaviours cannot easily be gauged at the international level.

Faced with pandemic threat, different countries have varied substantially in their reactions. These responses will be informed by a wide range of environmental and political influences, which impact on the speed, scale and efficacy of lockdowns.⁵ We compare China and the UK, two countries that varied in terms of exposure to COVID-19 in the life-cycle of the pandemic, number of cases and mortality rate, and the timing and stringency of their lockdowns and associated public responses⁵ (see online supplemental figure 1 for details). Less clear is the impact of these different policies on distress and pandemic behaviour. In China, almost 35% of the respondents reported psychological distress,⁶ with this distress greater in women and younger respondents. In the UK, national surveys suggest increased anxiety and stress as a result of COVID-19,¹ with greater anxiety among women and the young.⁷ While both countries recommended social distancing to tackle the pandemic, particularly from those who are symptomatic, the use of traditional medicines to reduce infection risk is more established in China.⁸ In this paper, we report data collected approximately 2 months after the first SARS-CoV-2 case in each nation. We do this to examine¹ the associations between demographics and risk of severe mental illness (SMI) in each country and² associations between risk of SMI, social distancing and self-medication (via vitamins and traditional medicines) in each nation.

RESULTS

In China, 217 of 1135 respondents (19.1%) were at risk of SMI (95% CI 16.9% to 21.6%), and in the UK, 215 of 1293 participants were at risk of SMI (16.6% (95% CI 14.6% to 18.8%)). Because of increased mortality risk from SARS-CoV-2 after the age of 40, respondents were grouped into below 40 or aged 40+. To assess predictors of SMI, we conducted logistic regression models—examining main effects and interactioneffects procedurally—on the probability of SMI. We examined main effects by entering, in a nested design, first, (1) sex, (2) age group, (3) quarantine status, (4) country, (5) relationship status and then (step 2) interaction effects by adding product terms, (6) age×country, (7) quarantine×country, (8) sex×country, (9) relationship×country and (10) quarantine×relationship. Results (table 2) showed significant interactions between agegroup and country and between quarantine and country, with the effect of quarantine stronger in China (in China: 42.3% in quarantine at risk of SMI vs 15.8% who were not (OR 5.98 (95% CI 1.77 to 20.24), p=0.004; in the UK: 25.4% vs 12.8%, OR 4.01 (95% CI 1.59 to 10.06), p=0.003). The simple age effect was significant only in the UK (OR 0.51 (95% CI 0.37 to 0.71), p=0.001); for China, OR 1.16 (95% CI 0.74 to1.81), p=0.53.

We then ran nested ordinal regressions on social distancing and self-medication, respectively, first entering risk of SMI, country, age, sex, relationship status, quarantine status and then the same interaction terms as for SMI (above). Those at less risk of SMI, older respondents and women were most likely to report social distancing, with an interaction between risk of SMI×country (Chinese respondents at risk of SMI social distanced less than those not at risk (mean 1.63 vs 1.94) but there was no significant effect in the UK (both Ms 1.91)). There were also interactions for social distancing for age×country, sex×country and marital status×country, with social distancing highest among British respondents who were older, female and in an intimate relationship (online supplemental table 1). Those at risk of SMI in both countries were more likely to report self-medication. Self-medication was higher overall among Chinese respondents, younger respondents, those who were single and those in quarantine. There were further interaction effects for age×country, quarantine×country and sex×country, with older Chinese, Chinese in quarantine and men in China most likely to self-medicate (online supplemental table 2).

DISCUSSION

SARS-CoV-2 presents a truly global health threat. We compared two different countries, China and the UK, chosen because of different caseloads and mortality rates and their public health responses to this threat. Those living under quarantine reported greater stress, with this effect stronger in China. Younger respondents also reported a greater mental health burden, with this association more pronounced in the UK. Risk of SMI predicted the use of self-medication in both countries, with older Chinese, Chinese in quarantine and men in China most likely to self-medicate. Risk of SMI was associated with lesser willingness to social distance in China and was greatest among British respondents who were older, female and in an intimate relationship.

Our findings suggest that, as elsewhere, quarantine is likely to be an important contributor to psychological distress. Mental health professionals need to be wary of this potential burden on health services.¹ The greater impact of quarantine in China may reflect the strict measures adopted in Hubei province (the area from which we recruited most of our quarantined participants) compared to the UK. There was also an associated potential for negative social labelling associated with living in an area of high infection, also observed in Hong Kong during SARS pandemic.¹⁰ A greater anxiety among younger respondents may be attributed to the greater use of online information among younger populations, with a consequent impact on (dis)trust.¹¹ The higher levels of distress among young people in the UK in particular may result from a lack of clarity in governmental messaging during this crisis,⁵ which encouraged a greater adherence to online conspiracy beliefs.¹² In contrast, social media is more regulated in China,¹³ which potentially limited the negative health impact of such accounts.

Our pancultural findings show a pancultural association between high levels of distress and willingness to self-medicate. While traditional medicine is well established in China, its role in the treatment of COVID-19 has been debated,¹⁴ with some arguing that its use may delay diagnosis and even lead to deleterious side effects.^{15 16} Practitioners in both countries need to work with broader healthcare systems to be clear about the usage of this medication during COVID-19. Messages that draw on a collective purpose and a sense of obligation to others may be particularly effective in the Asian context,¹⁷ while particular care must be taken in the UK to combat conspiracy theories that threaten effective health behaviour.¹² In doing so, it is important, too, to recognise intersectional variations: for example, while younger people were more likely to self-medicate overall, it was those aged over 40 years in China who were the most likely to perform this behaviour.

We recognise a number of limitations. Data were self-reported, and we tested only a limited number of pandemic behaviours. Although we used the same survey company for each study, both used a convenience sample and accessed different internet panels in each country, potentially limiting the range of potential respondents. Mental health is not stable across the life course,⁶ but the restricted age range of our Chinese sample, which was younger and less varied than our UK cohort, limited our ability to explore associations between age and mental health. Social distancing was adapted by the overwhelming majority of our respondents (more than 90%), limiting the variability in our predictors. We did not have data on income, education or occupation, despite disparities between such group in pandemic risk.¹⁸ We did not explore further predictors of distress or behaviour such as trust in government or other cultural or structural factors (eg, mask-wearing norms, access to education, housing types and availability). Finally, we used a measure of psychological distress (K6), which is relatively new and was not therefore widely employed during previous pandemics. This made it difficult to directly compare levels of psychological distress across analogous threats.

Data following SARS suggest a probable decline in the mental health burden of this novel coronavirus over time.¹⁹ Much however might depend on the future shape of the pandemic. As workers are encouraged to return to their workplace, those unable to maintain social distance at work may experience greater distress. Future research should further explore cross-cultural similarities and differences, comparing societies at similar time points in a pandemic to best gauge likely responses and motivate effective behavioural intervention.