Prevalence of depressive symptoms in US adults during the COVID-19 pandemic: A systematic review

The COVID-19 pandemic has led to a worsening of mental health among U.S. adults. However, no review to date has synthesized the overall prevalence of population depressive symptoms in the U.S. over the COVID-19 pandemic. We aimed to document the population prevalence of depressive symptoms and psychological distress across time since the start of the COVID-19 pandemic, both to identify patterns that emerged in the literature and to assess the data sources, methods, sampling, and measurement used to examine population mental health during the pandemic. In a systematic review of the peer review literature, we identified 49 articles reporting 88 prevalence points of depressive symptoms and related constructs in nationally representative samples of U.S. adults from March 2020 to June 2021. First, we found that the average prevalence of poor mental health across studies was 12.9% for severe depression, 26.0% for at least moderate depression, and 36.0% for at least mild depression. Second, we found that women reported significantly higher prevalence of probable depression than men in 63% of studies that reported depression levels by gender and that results on statistically significant differences between racial and ethnic groups were mixed. Third, we found that the 49 articles published were based on 12 studies; the most common sources were the Household Pulse Survey (n = 15, 31%), the AmeriSpeak panel (n = 8, 16%), the Qualtrics panel (n = 8, 16%), and the Understanding America Study (n = 5, 10%). Prevalence estimates varied based on mental health screening instruments and cutoffs used. The most commonly used instruments were the Patient Health Questionnaire (PHQ) (n = 36, 73%) and the Kessler (n = 8, 16%) series. While the prevalence of population depression varied over time depending on the survey instruments, severity, and constructs reported, the overall prevalence of depression remained high from March 2020 through June 2021 across instruments and severity. Understanding the scope of population mental health can help policymakers and providers address and prepare to meet the ongoing and future mental health needs of U.S. adults in the post-COVID-19 context and beyond.