In a recent study published in The Lancet Regional Health – Americas, researchers evaluated whether the various coronavirus disease 2019 (COVID-19) vaccine rollout phases impacted the prevalence of depression and anxiety at the population level among adults in the country.

​​​​​​​Study: Impact of phased COVID-19 vaccine rollout on anxiety and depression among US adult population, January 2019–February 2023: a population-based interrupted time series analysis. Image Credit: BaLL LunLa/Shutterstock.com

Background

A plethora of studies since the onset of the COVID-19 pandemic have reported that socio-economic and health-related disparities have been exacerbated for numerous individuals and families in the U.S. due to the pandemic. Evidence from substantial research suggests that the pandemic has had multi-faceted effects on mental health.

The compounded stressors of high morbidity and mortality rates associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and the social distancing and isolation protocols initiated by the government as disease mitigation measures are believed to have increased the prevalence of depression and anxiety in the population.

The financial stress from the inability to work due to numerous lockdowns during the pandemic would also have contributed to anxiety.

The rapid development and initiation of population-wide vaccination was expected to alleviate some of the stress and bring the people a sense of normalcy and optimism.

About the study

In the present study, the researchers conducted an interrupted time series analysis using deep-learning and autoregressive integrated moving average modeling to examine whether different COVID-19 vaccine rollout phases were associated with changes in the prevalence of depression and anxiety among the adult population of the U.S.

To mitigate the severe physical and mental health crises brought about by the onset of the COVID-19 pandemic, governments across the world allocated substantial resources to help pharmaceutical companies rapidly develop effective COVID-19 vaccines.

While these vaccines helped reduce the severity and transmissibility of the various SARS-CoV-2 variants in circulation, the vaccines were also expected to have a psychological impact in quelling fears and anxiety about the disease.

Although most of the research indicated a decrease in mental health symptoms after COVID-19 vaccines became available, some studies also reported an increase in mental health problems linked to a lack of trust in public health systems and vaccine hesitancy.

The rapid authorization of and misinformation about vaccines is believed to have exacerbated vaccine hesitancy and mental health concerns.

Furthermore, the policy of inequitable distribution of vaccines that was followed in the early stages of the pandemic to prioritize individuals at higher risk of COVID-19 could have potentially worsened the mental health and trust issues in many individuals.

The researchers used behavioral risk factor surveillance data from the U.S. Centers for Disease Control and Prevention (CDC) between 2019 and 2023 to evaluate the weekly changes in the prevalence of depression and anxiety following all the major phases of COVID-19 vaccine rollouts between 2020 and 2023.

The study also included major pandemic-associated events that could have impacted mental health conditions.

These included the earliest findings of a novel virus causing pneumonia-like disease, later identified as SARS-CoV-2, as well as the announcement of a nationwide emergency by the government.

The increase in breakthrough infections due to the Delta variant after the first few vaccine rollout phases was also included as one of the interruptive events in the study.

Results

The study found that the phased rollout of COVID-19 vaccines in the U.S. had disproportionate effects on the prevalence of depression and anxiety.

The results suggested a modest increase in the incidence of depression and anxiety among adults in the U.S. between 2019 and 2023, which was supported by findings from other studies that also showed an increase in these mental health issues from the pre-pandemic periods to after the pandemic.

However, a disparate pattern in the prevalence of mental health issues was also observed. A notable drop in the prevalence of depression and anxiety was observed after the vaccine rollouts covered childcare and education workers.

The researchers believe that providing COVID-19 vaccines to education workers and those involved in childcare could have alleviated the stress among those who were at a higher risk of SARS-CoV-2 infections due to their close association with children.

The resumption of in-person classes could also have decreased childcare stress among caregivers and reduced the anxiety associated with concerns about education continuity.

Similar patterns of decrease in depression and anxiety levels were observed when the vaccine rollouts included children below the age of five, indicating alleviated caregiver stress.

The first two phases of vaccine rollout were not associated with a decrease in depression and anxiety prevalence, and the researchers believe that shortage of vaccines and unequal vaccine distribution could have been contributing factors.

Furthermore, the first phase of vaccine rollouts was linked to a significant increase in depression and anxiety among people of African American origins and people of color belonging to other non-Hispanic races.

The high levels of vaccine hesitancy in these groups also suggested that historical systemic discrimination and racism, as well as ongoing inequity, could have led to vaccine mistrust and subsequent increase in mental health issues.

Conclusions

Overall, the findings indicated that phased COVID-19 vaccine rollouts had disparate effects on the prevalence of mental health issues such as depression and anxiety among the adult population of the U.S.

While some phases of the vaccine rollout were linked to a drop in the prevalence of mental health issues, the broader patterns highlight the need for better evaluation and planning initiatives.