COVID-19 mortality and its relationship with internet searches on mental health during the first year of pandemic

Few works have analysed the relationship between COVID-19 mortality and internet searches on mental health in Spain. The few studies that were undertaken indicate the existence of a position association between the number of deaths due to COVID-19 and the volume of internet searches using the terms anxiety¹ and insomnia.^1,2 These studies only examine this association during the first weeks after the declaration of COVID-19 as a pandemic (more specifically, from 13 to 19 April 2020)^1,2 and not all of them include internet searches using the key words anxiety² or stress,^1,2 as these terms were usually examined in previous studies of this subject.^3–5 Given the situation described above, the aim was to analyse the association between the variation in the number of deaths due to COVID-19 in Spain and the numbers of web searches using different mental health concepts (more specifically, anxiety, depression, stress, insomnia and suicide) in the period from March 2020 to March 2021.

The data on COVID-19 deaths used in this analysis were taken from reports on the pandemic situation in Spain supplied by Worldometers⁶ from 1 March 2020 to 6 March 2021. Data on the daily number of deaths due to COVID-19 were recorded in the platform, and the weekly number of deaths were then calculated during this period. This web resource has been used before in the literature for the statistical study of mortality due to COVID-19.^7,8 Internet search tendencies for mental health were identified using Google Trends.⁹ This tool gives an index on the relative search volume (RSV) for different key words in a specific period of time and for a certain geographical area. This RSV varies from 0 to 100, where 100 is the score which indicates the highest volume of web searches for a specific term within the selected search category within a specific period of time. Data were recorded on the RSV for terms in connection with mental health (TCMH): “anxiety”, “depression”, “stress”, “insomnia” and “suicide” during the period from 1 March 2020 to 6 March 2021. Searches had to have originated in Spain in all categories of internet search (science, news, health, literature, etc.).

Fig. 1A shows that anxiety is the subject with the highest average volume of searches in the year studied (average RSV = 78.70 ± 8.72), followed by depression (average RSV = 27.57 ± 3.96), stress (average RSV = 21.91 ± 3.01), suicide (average RSV = 17.42 ± 4.67) and insomnia (average RSV = 9.40 ± 2.72). During this period of time the weekly number of deaths due to COVID-19 correlated positively and significantly with the weekly RSV for the terms “anxiety” (r = 0.59; P < .001), “stress” (r = 0.41; P < .001) and “insomnia” (r = 0.49; P < .001).

Figure 1.

A) Relative search volume (RSV) scores for the terms “anxiety”, “depression”, “stress”, “insomnia” and “suicide” and the number of deaths per week due to COVID-19 in Spain from 1 March 2020 to 6 March 2021. B) Scatter diagrams and adjusted R squared values for the relationship between the number of deaths per week due to COVID-19 and the RSV for “anxiety”, “stress” and “insomnia” in Spain during the period from 1 March 2020 to 6 March 2021.

In the lineal regression performed after the correlation analysis, the number of weekly deaths due to COVID-19 remained positively associated with the volume of internet searches for “anxiety” (B = 0.004; t = 5.26; P < .001), “stress” (B = 0.001; t = 3.21; P = .002) and “insomnia” (B = 0.001; t = 4.03; P < .001). The adjusted determination coefficients obtained (Fig. 1B) showed that the number of deaths per week due to COVID-19 explained 34% (F = 42.36; P < .001) of the variance in the volume of internet searches for anxiety, 15.3% (F = 10.36; P = .002) for searches about stress and 22.9% (F = 16.24; P < .001) in the case of searches for insomnia.

These results show that the variation in the number of weekly COVID-19 deaths is associated and explains a significant percentage of variance of public interest in the subjects of anxiety, stress and insomnia as shown by the Google Trends RSV scores. These findings may indicate that the association between the increase in coronavirus deaths and the rise in public interest about the subjects of anxiety and insomnia, as reported by studies undertaken in the first weeks of the pandemic,^1,2 may be seen in cross-section when a yearly period is analysed. The chief limitations of this work would be that Google Trends solely collects data on individuals who use Google as a search engine, and that the search volumes it supplies are relative and not absolute.^10,11

To conclude, in Spain the periods of high viral activity with the highest number of COVID-19 deaths may have had a specific impact on the levels of anxiety, stress and insomnia in the population, reflecting a higher number of web searches for information about these psychopathological processes. A high level of need for information about these specific mental health subjects can be inferred to exist in the Spanish population, associated with the variability in mortality due to COVID-19.

Financing

This study was partially financed by UNIR Research (http://research.unir.net), La Rioja International University (UNIR, http://www.unir.net), under research project grants — RETOS-UNIR [2016–2018], [2018–2020], [2020–2022] “PSICONLINE”, by the Ministerio de Economía, Industria y Competitividad (MINECO) in the grant Retos-Investigación I+D+I 2017 (PSI2017-82542-R), and by the Alicia Koplowitz Foundation in the 2020 research project grants.

Conflict of interests

The authors have no conflict of interests to declare.