The COVID-19 pandemic and its associated preventive public health and containment measures have impacted individuals globally in myriad ways, ranging from job and financial losses, everyday life restrictions through lockdowns, curfews or remote work or school, to disease-related impairments such as illness or death. Life changed drastically within a short period of time, putting a strain on mental health and wellbeing as reports from many countries around the world confirmed (1–5). Increased prevalence of depression, anxiety, stress and insomnia have been reported (6–8), as well as changes in alcohol and other drug use (9). Moreover, individuals have been affected by the pandemic inequitably (2, 10, 11).

Certain subgroups of the population appear to be at higher risk of substance use and mental health issues during the pandemic, particularly children and adolescents (12), younger adults, people who were unemployed (10) or living alone (7), people with poor physical health or pre-existing mental health conditions, and women (13, 14). Specifically, increased alcohol use has been reported among younger and older adults, and among those with higher pre-pandemic alcohol use or higher levels of stress; other studies have found varying results in regard to socio-demographic characteristics (9, 13, 15), possibly due to a lack of broad data collection on a large scale and differences in the populations studied (e.g., older adults, college students, or patients with pre-existing mental health conditions). This lack of comprehensive data makes targeted prevention, screening, identification, and early intervention efforts for (subgroups of) the general primary care population more challenging.

Alcohol use problems can be effectively identified in primary care (16, 17) with adequate screening, as many people, particularly in high and middle-income countries have access to regular primary care; however, there are still significant gaps in the literature about how alcohol use, other mental health issues, and health care utilization have changed since pandemic onset. Thus, more research is needed for healthcare systems to prepare for adequate screening and intervention efforts, particularly for young adults. Importantly, patterns of alcohol use are frequently established during young adulthood, and thus, there are opportunities to intervene and change people's trajectories of drinking during this period of vulnerability (18). Moreover, young adults may have been very severely affected by the pandemic due to factors such as less job security, housing stability, and higher debt compared to other age groups. Previous studies have reported higher distress and mental health issues caused by the pandemic and its containment measures in younger adults (19–21). Therefore, the aim of this study was to examine impacts of the COVID-19 pandemic on alcohol use problems among a diverse, large sample of young adults (18–34 years) who utilized primary care. Specifically, we compared changes in prevalence of unhealthy alcohol use from pre- (March 1, 2019 to December 31, 2019) to post-COVID onset (March 1, 2020 to December 31, 2020), and potential heterogeneity by patient-level factors, including sex, age group (18–20 vs. 21–34), race/ethnicity, socio-economic status, as well as mental health conditions and healthcare utilization data.

Among a large sample of young adults in Northern California who utilized primary care, we found a small, but significant, overall decrease in prevalence of unhealthy alcohol use following onset of the COVID-19 pandemic compared to the year prior; however, this decrease was not equal across patient subgroups, underscoring the importance of examining heterogeneity in alcohol use studies. The overall decrease in prevalence appears to have been largely driven by men; patients aged 21–34 years, White, API, Black, and Native American patients; and patients living in neighborhoods with the lowest NDIs (higher SES); some of these subgroups (men, White, Black, and Native American patients) have typically had higher prevalence pre-COVID (34). In contrast, the prevalence of unhealthy alcohol use increased slightly, with similar magnitude, among young women, those aged 18–20 years (below the legal drinking age in the U.S.) and Latino/Hispanic young adults, pre- to post-COVID onset. These data cannot tell us why unhealthy alcohol increased among subgroups, but stress, anxiety, depression, social isolation, and suicidal thoughts elicited by the pandemic might have played a role, since these factors have been associated with changes in the consumption of alcohol and other substances (9, 35–37). Some of these factors may be more prominent in certain subgroups. For example, studies have found that level of alcohol problems was associated with loneliness only for women (38), and significant associations between early-COVID-19 period, depression and anxiety symptoms, and drinking to forget one's worries among women only (39). Research also found higher psychological distress among young adults aged 18–24 years and Hispanic/Latino individuals during the pandemic (40, 41). Moreover, the national Monitoring the Future study (42) that examined historical trends and potential 2020 shifts in prevalence and frequency of drinking, also reflected the downward trend in past 30-day alcohol use in young adults that we found in California; however, the authors also noted more binge drinking compared to prior to the pandemic as well as changes in drinking contexts and reasons among drinkers (such as increased boredom, drinking to relax, and drinking while alone).

While effect sizes for these changes in prevalence of unhealthy alcohol use were very small, the increases observed among young adult women, adults younger than the U.S. legal drinking age, and Latino/Hispanic young adults in our study reflect national trends (43–48), which are concerning for several reasons. Whereas, Latino/Hispanic members in the U.S. are generally less likely to drink compared to non-Hispanic Whites, those who drink tend to drink larger quantities (49). This dynamic is even more apparent in subgroups with higher levels of acculturation to the American culture, those who have more relaxed attitudes toward drinking and young women with Latino/Hispanic background (49). Moreover, members of the Latino/Hispanic communities tend to be less likely to seek treatment for alcohol-related problems (49). In general, women are more likely than men to progress faster to AUDs and experience more serious alcohol-related health problems (50, 51). Several recent studies have shown that women in the U.S. are increasingly drinking more and that the gender gap is narrowing, particularly among the younger cohorts (34, 52, 53). Thus, our pandemic-related findings may indeed reflect a troubling closing in the historical gaps in drinking behaviors between socio-demographic subgroups, and thus, an overall trend in our society (54).

Our findings provide important information for health systems and could help inform targeted screening and brief intervention efforts. The finding that unhealthy alcohol use may be increasing among vulnerable sub-groups even in the context of overall (54) decreases suggests that clinicians may need to focus increased attention on groups which may not have been perceived at high risk of unhealthy alcohol use in the past. Primary care providers of SBIRT (screening, brief intervention, referral to treatment) may use this information to assess the potential need in their young adult patients for more targeted (early) interventions or prevention programs. Particularly now, as telemedicine has become more common during the pandemic, there may be more opportunities to provide SBIRT through telehealth/virtual approaches, which may appeal to these vulnerable young adults and increase ways for clinicians to reach young people and help them develop healthier behavioral alternatives. More research examining utilization and effectiveness of telehealth services among young adults following onset of the COVID-19 pandemic is greatly needed.

Our study has a number of limitations. Alcohol use was self-reported and thus subject to potential under-reporting. Additionally, alcohol use could only be assessed among members who had primary care visits and were screened during the study periods. Patients may not have been screened during the study period if they were not due for screening (screening is conducted annually, or every 6 months if a prior screening indicates unhealthy alcohol use) or other reasons such as busy workflows or medical assistants forgetting to administer the screening instrument. In addition, the percentage of young adults screened in primary care was lower post-pandemic onset compared to the year prior; this is most likely due to the pandemic (onset) interrupting clinical workflows, and the need to adapt and shift to virtual care. Although there were some differences between those who were screened vs. not screened, we adjusted for potential selection bias with a propensity score weighting approach that is appropriate for re-balancing characteristics of the study sample. However, generalizability of the study findings remains limited to young adults who use primary care services. In addition, there may be moderating factors that we are not able to measure with our data such as acute individual stressors or social determinants of mental health and substance use (e.g., housing or job insecurity or childcare issues). We did not find any significant associations between mental health and drug use and unhealthy alcohol use prevalence changes in our sample, suggesting that other factors might play a role in this regard. The reasons why certain subgroups had differential changes in prevalence of unhealthy alcohol use pre- to post-pandemic onset are critical for future studies to examine.

Our analysis of changes in self-reported drinking behavior in this large, socio-demographically diverse sample of young adults revealed important trends in regard to unhealthy alcohol use. Groups who may have engaged in less unhealthy use in the past, e.g., young women compared to their male counterparts, may be closing these gaps and putting themselves at increased risk of alcohol-related harms as they have higher prevalence of unhealthy alcohol use post-COVID onset. These vulnerable groups might need special attention or targeted efforts to prevent further progression of this trend as the pandemic continues to impact our everyday lives.

The datasets presented in this article are not readily available because the analytical datasets from this project include patient level data from the KPNC EHR, administrative and clinical databases. External investigators can contact the study PI to initiate a request for study data to support new study proposals or article. Approval of such requests and initiation of collaborations will consider the following criteria: The proposed project must be of high scientific merit. The proposed project must be consistent with the overall goals and objectives of the parent study. The proposed project must meet certain participant burden criteria (for any new primary data collection involving subjects), including: Acceptable to the subjects (e.g., risks, time, discomfort, and privacy); and not hinder or disrupt clinical care provided by study sites. The proposed project's investigators must plan for adequate resources to effectively complete the project, including: Sufficient budget to cover costs of personnel and supplies; and staff possessing the requisite expertise to meet the objectives of the project. The proposed project should document any involvement of parent study investigators as part of the research team. Approved requests for data will take into account data sharing agreements between KPNC and NIH. Data will be de-identified prior to release for sharing. Requests to access the datasets should be directed to stacy.a.sterling@kp.org.

The studies involving human participants were reviewed and approved by IRB of Kaiser Permanente Northern California. Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.

VM, VP, FC, CC, and SS contributed to the concept and methodology of the study. VP and FC conducted the analysis and were responsible for gathering the relevant data from the electronic health records. CC and SS supervised all publication-related activities and obtained funding for the project. VM conducted the submission. All authors contributed to writing and editing the manuscript and approved the submitted version. All authors agree to be accountable for the content of the work.

This research was supported by a grant from the National Institute on Alcohol Abuse and Alcoholism: R01AA027477 (PI: SS).

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.