A global increase in the prevalence of anxiety, depression and major depressive disorder (MDD) has been associated with the SARS-CoV-2 (severe-acute-respiratory-syndrome-related coronavirus) pandemic (World Health Organization, 2022). This increase has also presented an inequitable pattern with 26.6 % of American Indian/Alaskan Native (AIAN) adults experiencing mental illness compared to 22.8 % of all U.S. adults in 2021 (National Alliance on Mental Illness (NAMI), 2023). Major depressive disorder increases suicide risk (Cai et al., 2021) and is a chronic condition that can cause serious functional impairment, substantially interfering with activities of daily living and health related quality of life (Cambridge et al., 2018). The prevalence of major depressive episodes (MDE) in young AIAN adults (18–25 years) quadrupled from 3.6 % in 2016 to 15.4 % in 2019, during the onset of the SARS-CoV-2 pandemic (2019 National Survey on Drug Use and Health: American Indians and Alaska Natives (AI/ANs), 2020). Though depression and other mental health symptoms were well studied during the SARS-CoV-2 pandemic (Ettman et al., 2023), little research has examined impacts on AIAN populations, especially as a comparator group. Of the limited literature published, one nationally representative cross-sectional survey (December 2020 and February 2021,n = 5500) did distinguish AIAN from other racial and ethnic groups and found significantly higher (p < 0.05) moderate/severe levels of anxiety-depression symptoms (32.1 % vs 25.6 %) and moderate/severe levels of stress (40.9 % vs 33.7 %) in this group compared to non-Hispanic Whites (Nápoles et al., 2023).

Indigenous Social Determinants of Health (SDoH) represent a broader understanding of physical, mental, social, spiritual and cultural components that are couched in local personal and community context (Milroy, 2006) with Indigenous specific SDoH include self-determination, cultural attachment, relationship with land, social capital, racism and justice systems (Gracey and King, 2009). Other SDoH include socioeconomic status, education, income, employment, housing, social supports, access to health care and adverse SDoH play an important role in disparate mental health outcomes (Alegría et al., 2018; Deferio et al., 2019), however there remains a paucity of research characterizing the associations between broader social and structural determinants and mental health outcomes among AIAN.

In 2020, AIANs had the highest unemployment rate in the U.S. (11.7 % vs 7.3 % for non-Hispanic Whites), coinciding with the lowest labor force participation rate (59.3 %) and employment-population ratio (52.4 %) in the country (U.S. Bureau of Labor Statistics, 2021). Employment has been associated with positive social identity and status, psychological wellbeing, improved physical health, and reduced mortality (Waddell and Burton, 2006). Long-term unemployment can result in symptoms of isolation and depression, as well as family and social disruption and declines in physical and psychological health (Paul and Moser, 2009; Wanberg, 2012). Discrimination during the job seeking and on-the-job experiences also impact psychological well-being. A nationally representative, probability-based telephone survey found approximately three in ten AIAN adults reported being personally discriminated against because of their race when applying for jobs (31 %), in circumstances involving equal pay, and when being considered for promotions (33 %) (Findling et al., 2019). Despite this, there is a lack of information surrounding the health benefits of good work for Indigenous peoples, and specifically on the association between depression, depressive symptoms and mental health outcomes and employment and employment characteristics, in part due to limitations of race/ethnicity definitions and small samples in available data sources.

Using the social determinants of health theoretical framework, we aim to evaluate the relationship between depressive symptoms, diagnoses and treatment and employment status and related social determinants of health in AIAN adults. Utilizing the National Health Interview Survey (NHIS) data for years 2020 to 2022, we aim to evaluate the relationship between employment status and depressive symptoms, diagnoses and treatment in AIAN adults.

Of working age AIAN adults, an estimated 605,040 persons reported depressive symptoms, or 15.8 %(95%CI:13.4–18.1) of adults (in the weighted sample) aged 18 to 65. Of Indigenous adults working, 13.1 % (95%CI:9.7–16.5) reported depressive symptoms, compared to 20.6 % (95%CI:16.6–24.6 %) of non-working Indigenous adults. For comparison, depressive symptoms in working age adults were reported in 12.0 % (95%CI:11.6–12.5) of non-Hispanic White, 7.9 %(95%CI:7.2–8.5) of Hispanic, and 9.8 %(95%CI:8.8–10.7) of African-American adults. Table 1 presents the demographic characteristics of Indigenous adults by work status and depressive symptoms. Among individuals reporting depressive symptoms, working persons were more educated, had a higher family income and were more likely to be living in urban areas than non-working persons. Non-working AIAN adults with depressive symptoms were significantly older (mean age 46.2, SE 3.2) than all other groups. Both working and non-working groups reporting depressive symptoms were predominantly female. Among working Indigenous adults only, those reporting depressive symptoms were more likely to be divorced, less likely to have completed a bachelor’s or graduate degree, and more likely to have a family income 200 % below the poverty line. Non-working Indigenous adults with and without depressive symptoms were similar across most demographic traits; however, non-working adults with depressive symptoms disproportionately reported family income 200 % below the poverty line with rural residency in the South and West of the U.S. Service workers made up nearly one-third (32 % 95%CI:16–48) of the AIAN workforce that reported depressive symptoms. Comparatively, service workers only made up 16 % of the AIAN workforce that was not reporting depressive symptoms (16.3 % 95 % CI:12.2–60.3). The prevalence of depressive symptoms in workers differed significantly by sick leave benefits, with higher depressive symptoms in workers without paid sick leave.Table 2 presents health characteristics of Indigenous adults by working status and depressive symptoms, demonstrating working adults with depressive symptoms had significantly lower self-reported health status and higher proportions of workers with any disabilities or delays in healthcare due to cost compared to workers without depressive symptoms.

AIAN adults who reported depressive symptoms were more likely to report their general health status as good, fair or poor; have two or more comorbidities; have been diagnosed with anxiety and/or depression; have a disability; have difficulty with remembering/concentrating, vision, hearing, and mobility; experience pain daily; have pain that limits life or work activities at least some days and pain that affects their families and significant others at least some days regardless of work status. Nearly half of non-working AIAN adults with depressive symptoms experienced daily pain. Health care utilization was higher among those reporting depressive symptoms, regardless of work status.

Of the working AIAN group with depressive symptoms, 60 %(95% CI:47.5–73.3) were taking either anti-depressant medications or had received mental health therapy in the past 12 months; this reduced to 10 %(95%CI:7.3–13.3) of the AIAN working adults who did not report current depressive symptoms. Of the non-working AIAN group with depressive symptoms, there were 56 %(95 % CI 44.3–68.0) currently taking depression medications or who had received mental health therapy in the past 12 months; this reduced to 17.5 %(95 % CI:11.0–24.0) of the AIAN non-working adults who didn’t report current depressive symptoms.

In the first set of models (Table 3) we compare working and non-working AIAN adults to evaluate differences in mental health-related outcomes. In the multivariable logistic regression models controlling for age, sex, marital status and education, AIAN adults who were not working when compared to working adults had significantly higher odds of depressive symptoms (aOR = 1.55;95 % CI: 1.03–2.33), taking a medication for depression (aOR = 1.73; 95%CI:1.15–2.59), receiving mental health therapy in the last 12 months (aOR = 1.75; 95% CI:1.19–2.58), and ever being diagnosed with depression (aOR = 1.50; 95%CI:1.02–2.21) or anxiety (aOR = 1.75; 95%CI:1.25–2.44). Table 4 presents a second set of multivariable models outlining predictors associated with mental health-related outcomes among working Indigenous adults only. Female workers had significant higher odds of current medication use for depression and having a previous diagnosis of depression (p value<0.05). Adults without a university degree and adults aged 30–39 years (reference older than 50 years) had significantly higher odds of receiving mental health counselling in the prior 12 months. Self-reported pain on most or all days was a significant predictor of all mental health outcomes. No sick leave benefits from employee’s current workplace were included as an indicator of poor employment quality and was significantly associated with having a prior diagnosis of depression. Occupation type was included in models shown in Table 5. Occupation and industry data were only included in 2020 and 2021 in NHIS, therefore restricting use of 2022 data reducing the sample size in these models. Blue collar jobs were used as the reference group as we found that service jobs had significantly higher odds for depressive symptoms and previous diagnosis of depression and white-collar jobs had significantly higher odds of previous diagnosis of depression and mental health therapy in the past 12 months.

Table 6 presents a third set of multivariable models outlining predictors associated with mental health-related outcomes among non-working AIAN adults only. Adults without a university degree had significantly lower odds of current depression medication use. Females had a significant higher odds of current depression medication use and adults self-reporting any disability had significantly higher odds of current depressive symptoms and previous diagnosis of depression.

Using a nationally representative sample, we found that AIAN adults who were not currently employed during the previous week in any capacity had higher odds of reporting weekly/daily depressive symptoms and ever being diagnosed with depression compared to employed AIAN adults. Stratified models showed that predictors of mental health outcomes differed between working and non-working AIAN adults, including age, education, location, health care usage, and delay of mental health treatment.

Factors contributing to depressive symptoms in older adults may include life stressors, medical illness and functional disability, trauma, lower income and education, bereavement, lack of social support, and loneliness (Aziz and Steffens, 2013). Negative influences on mental health in AIAN adults may include detrimental impacts of land dispossession (Moreton-Robinson, 2015), while protective factors may include culture, social supports and self-regulation (Vecchio et al., 2022).

The working AIAN adult depressive group had the highest proportion with delays in care, medications, and counselling due to cost. Many AIANs still live in rural areas, but only 22 % live on reservations or land trusts where the Indian Health Service (IHS) is located, and as of 2010, 60 % of AIANs lived in metropolitan areas outside of IHS areas, creating significant barrier in access to health care (U.S. Department of Health and Human Services, Office of Minority Health, n.d; Forquera, 2001).

Gender disparities are consistent with findings in the general U.S. population, where women were nearly twice as likely than men to have taken medication for their mental health (21.2 % and 11.5 %, respectively) and more likely to have received counselling or therapy from a mental health professional (12.1 % and 7.9 %, respectively) (Terlizzi and Norris, 2020). The significantly higher rates of depressed symptoms for service workers could be related to the SARS-CoV-2 pandemic, with very high rates (74–78 %) of depressive and anxiety symptoms reported in large convenience samples of essential workers during the pandemic (Amsalem et al., 2023). International research has also demonstrated that service workers experience of depressive and anxiety symptoms are incrementally related to the frequency in engagement with complaints and suppression of workers’ emotions (Yoon et al., 2017). Service-related occupations (e.g. retail) are also characterized by poor social benefits, lower wages (Allegretto et al., 2013), shift work and work that is precarious in nature (Choper et al., 2021).

Younger AIAN workers were also significantly more likely to have received mental health therapy which was consistent with reporting on all U.S. adults (Terlizzi and Zablotsky, 2020). National data demonstrates higher use of mental health medications in older adults (>44 years) and higher use of therapy and counselling modalities in younger adults (<45 years) (Terlizzi and Zablotsky, 2020). Modality and efficacy of specific mental health treatments by age group may be an important consideration in future Indigenous research.

Discrimination among AIAN adults is an indicator of depressive symptoms, and traditional practices is a protective factor (Whitbeck et al., 2002). Poor employment quality including low wage jobs, discrimination and removal from traditional ties (Masotti et al., 2020) contribute to negative mental health among Indigenous individuals, while personal achievement, decent work and social benefits can bolster mental health. Community level interventions that consider these factors have yet to be studied.

Generally, it is known that decent work is good for an adult’s mental health and this collides with a growing focus worldwide on corporate, community and public organizations’ development of Indigenous employment strategies (Illinois Department of Central Management Services, 2023). These strategies are important as a tool for implementing changes, monitoring targets and improving accountability for inclusion, retention, and career progression of Indigenous workers. Cultural safety at work - an environment absent discrimination based on a person’s identity (Williams, 1999), is particularly important, given the potential of a culturally unsafe work environment to synergize with other aspects of low quality work to adversely affect mental health; those with a preexisting diagnosis or susceptibility to depression and other mental health conditions are at particular risk. Improving the burden of depression and related mental health outcomes experienced by the AIAN workforce requires a stronger evidence base to inform policy and practice. Baseline information on working conditions that would promote the physical and psychosocial health of Indigenous workers, as well as the barriers to quality employment and related staff satisfaction, are needed; this is particularly important for AIAN adults with comorbid conditions. Further, appropriate tools to assess psychosocial risk in the workplace through a cultural lens, and the collection of race/ethnicity data against a range of occupational health measures, are required. Such evidence will be critical to addressing barriers and enablers of cultural safety and reduction of the risk of work-related depression. This has been impeded by small numbers of Indigenous employees in specific workplaces and/or occupations, but could be remedied by studies intentionally designed to address work and health among AIAN workers. These would include oversampling in surveys, application of community based participatory research, research advisory boards, and targeted intervention studies (i.e., translational research). Importantly, future research should carefully consider cultural safety, privacy protection and confidentiality of AIAN workers. The authorship has developed a framework for consideration of future Indigenous occupational health indicators that requires further feedback from AIAN occupational health stakeholders to develop key indicators made by and relevant to Indigenous people prior to publication.

This study has several limitations. First, NHIS estimates are based on self-reported employment status, with 62.5 % of AIAN adults 18–65 years reporting current employment. For comparison, BLS provides aggregated estimates from 2019 to 2021 that report only 55 % of AIAN adults 16 years and over are employed; this lower percentage is expected lower percentage when including those 16–18 years and those >65 years (Brundage, 2023), likely associated with social, structural and health barriers to employment based on age. Secondly, there are numerous important factors not queried in the survey, specifically more rigorous information on depressive symptoms, treatments and protective factors related to mental health, and factors specific to Indigenous adults. Thirdly, indicators of quality of work, including work-time arrangements, employment stability, length of current employment, current worker rights, cultural safety at work, training and promotion are missing from NHIS and other national surveys. Finally, national survey designs are problematic for sampling very small minority subpopulations, particularly AIAN adults, who are geographically clustered in some areas, such as rural Indian reservations, and dispersed and geographically invisible in areas such as urban centers. Another limitation is that the NHIS study design limits causal inference. There is a need for investing in longitudinal studies that appropriately include representation of indigenous people in order to further elucidate the relationships identified in this analysis.

In summary, to promote good mental health among AIAN populations, it is critical to build on the evidence regarding the influence of employment conditions and workplaces on mental health, with prioritization of AIAN funding, multisector collaboration, and adequate resourcing for communities to support sustainable local level strategies.