Policy stringency and mental health during the COVID-19 pandemic: a longitudinal analysis of data from 15 countries

Abstract

Background: To date, public health policies implemented during the COVID-19 pandemic have been evaluated on the basis of their ability to reduce transmission and minimise economic harm. We aimed to assess the association between COVID-19 policy restrictions and mental health during the COVID-19 pandemic.

Methods: In this longitudinal analysis, we combined daily policy stringency data from the Oxford COVID-19 Government Response Tracker with psychological distress scores and life evaluations captured in the Imperial College London-YouGov COVID-19 Behaviour Tracker Global Survey in fortnightly cross-sections from samples of 15 countries between April 27, 2020, and June 28, 2021. The mental health questions provided a sample size of 432 642 valid responses, with an average of 14 918 responses every 2 weeks. To investigate how policy stringency was associated with mental health, we considered two potential mediators: observed physical distancing and perceptions of the government's handling of the pandemic. Countries were grouped on the basis of their response to the COVID-19 pandemic as those pursuing an elimination strategy (countries that aimed to eliminate community transmission of SARS-CoV-2 within their borders) or those pursuing a mitigation strategy (countries that aimed to control SARS-CoV-2 transmission). Using a combined dataset of country-level and individual-level data, we estimated linear regression models with country-fixed effects (ie, dummy variables representing the countries in our sample) and with individual and contextual covariates. Additionally, we analysed data from a sample of Nordic countries, to compare Sweden (that pursued a mitigation strategy) to other Nordic countries (that adopted a near-elimination strategy).

Findings: Controlling for individual and contextual variables, higher policy stringency was associated with higher mean psychological distress scores and lower life evaluations (standardised coefficients β=0·014 [95% CI 0·005 to 0·023] for psychological distress; β=-0·010 [-0·015 to -0·004] for life evaluation). Pandemic intensity (number of deaths per 100 000 inhabitants) was also associated with higher mean psychological distress scores and lower life evaluations (standardised coefficients β=0·016 [0·008 to 0·025] for psychological distress; β=-0·010 [-0·017 to -0·004] for life evaluation). The negative association between policy stringency and mental health was mediated by observed physical distancing and perceptions of the government's handling of the pandemic. We observed that countries pursuing an elimination strategy used different policy timings and intensities compared with countries pursuing a mitigation strategy. The containment policies of countries pursuing elimination strategies were on average less stringent, and fewer deaths were observed.

Interpretation: Changes in mental health measures during the first 15 months of the COVID-19 pandemic were small. More stringent COVID-19 policies were associated with poorer mental health. Elimination strategies minimised transmission and deaths, while restricting mental health effects.

Funding: None.

Figure 1

Comparison of pandemic intensity (A) and policy stringency (B) between April 27, 2020, and June 28, 2021, in 15 countries adopting mitigation and elimination strategies Data for 11 countries that followed a mitigation strategy and four countries that followed an elimination strategy. Lines represent mean 2-weekly values averaged over all countries in each strategy grouping. Shaded areas represent the range between minimum and maximum daily country means. Pandemic intensity was measured by by the number of daily deaths per 100 000 population.

Figure 2

Policy strength of selected policy indices in countries adopting mitigation and elimination strategies between April 27, 2020, and June 28, 2021 Data for 11 countries that followed a mitigation strategy and four countries that followed an elimination strategy. Lines represent mean fortnightly values averaged over all countries in each strategy grouping.

Figure 3

Psychological distress (A) and life evaluations (B) reported in countries adopting mitigation and elimination strategies between April 27, 2020, and June 28, 2021 Data for 11 countries that followed a mitigation strategy and four countries that followed an elimination strategy. Lines represent mean fortnightly values averaged over all countries in each strategy grouping. Shaded areas around the lines represent the range between minimum and maximum observed country means. Pre-pandemic (2019) country mean of life evaluations were retrieved from the World Happiness Report.

Figure 4

Standardised associations between policy stringency and mental health scores Estimates of the effects of stringency on the logarithm of daily deaths are based on Hale et al. Estimates of associations of policy stringency on mental health 56 and 168 days after policy change are based on a combination of estimates from Hale et al and our own estimates (appendix pp 67–70). The indirect association was larger when daily deaths rates were higher and the potential for future reductions in mortality was larger. For a representative example of the magnitude of the indirect associations, we considered a scenario with daily deaths at the average of peaks for countries that adopted a mitigation strategy in our sample (0·868 daily deaths per 100 000 population) at the time of stringency change. Standard errors for non-contemporaneous associations scenarios were derived from contemporaneous effects. Horizontal lines show 95% CIs.