Insurance coverage

Demographics and health insurance coverage of non-elderly adults with mental illness and substance use disorders in 2020

The pandemic has aggravated the underlying mental illness and substance use disorders, particularly for certain subgroups, and difficulties in accessing treatment may have increased. In this briefing note, we use 2020 data from the National Survey of Drug Use and Health (NSDUH) to examine key characteristics, coverage and health status of non-elderly adults with the disease. mental or substance use disorders to inform ongoing federal and state efforts to improve quality and expand access.

This analysis is based on the NSDUH definitions of mild, moderate, or severe mental illness using DSM-IV Criteria. those with severe mental illness (SMI) often have difficulty with activities of daily living, comorbid conditions like substance use disorders and physical conditions, and in general, people with mental illness die sooner than those without. NSDUH uses DSM-V diagnostic criteria to assess the presence of substance use disorders. These disorders are categorized into mild, moderate, and severe groups based on the severity of the symptoms. In addition to legal substances such as alcohol and sometimes marijuana, substance use disorders can also involve illicit substances such as opioids and cocaine. Due to the pandemic, NSDUH data is limited to the first and fourth quarters of 2020, with survey data collection shifting from in-person interviews to online surveys, so the data cannot be compared to other years. Small sample sizes preclude subgroup analyzes among the uninsured population.

Key findings include the following:

  • Mental illness and substance use disorders affect a third (64.5 million) of all non-older adults in 2020 and are more prevalent among young adults and white people. Other data and research indicate deterioration young adult mental health and people of color during the pandemic. The lower rates in people of color may reflect underdiagnosis among these groups. Data shows that women have higher rates of mental illness, while men have higher rates of substance use disorders.
  • Most non-elderly adults with mental illness or addiction are covered by private insurance (58%), but those enrolled in Medicaid are more likely to have these conditions. Those enrolled in Medicaid also have the highest overall prevalence of moderate to severe mental illness or substance use disorder.
  • Among non-elderly adults with moderate to severe mental illness or substance use disorder, those enrolled in Medicaid are more likely than those with private insurance to have chronic conditions and to report fair or poor health.

What is the prevalence of mental illnesses and substance use disorders and what are the characteristics of people with these disorders?

One-third (33%) of all non-older adults have a mental illness or substance use disorder. Mental illness affects 23% (45.3 million) of non-elderly adults, with 11% having mild conditions, 6% moderate conditions and 6% severe conditions. About 18% (34.7 million) of non-older adults have some form of substance use disorder, with milder disorders (10%) accounting for the majority. People with severe mental disorders and substance use disorders often have complex health needs including several comorbiditiesmore difficulties in daily life and a greater likelihood of premature death. An estimated 8% (15.5 million) suffer from both a mental illness and a substance use disorder and, combined, 33% (64.5 million) of non-older adults suffer from a mild, moderate or severe mental illness or substance use disorder (Figure 1).

Mental illness or substance use disorders are more common among young adults and non-elderly white people. Mental illness is most common among young adults aged 18-25 (30%) and lowest among adults aged 50-64 (17%). Among young adults aged 18 to 25, the rate of substance use disorders is 24%, twice as high as that of adults aged 50 to 64 (12%). More than a quarter (26%) of whites suffer from mental illness; this is the highest rate of any race or ethnicity. Whites are more likely to report substance use disorders (19%) than Hispanics (14%) and Blacks (16%). These findings for higher rates apply to mild, moderate, and severe mental illnesses and substance use disorders and co-occurring mental illnesses and substance use disorders (Figure 2). Other data and research indicate deterioration young adult mental health and people of color during the pandemic. A lack of cultural sensitivity screening tools that accurately detect mental illness, coupled with structural barriers, can lead to underdiagnosis mental illness in people of color.

Women have higher rates of mental illness, while men have higher rates of substance use disorders. Compared to men, women are more likely to suffer from mental illness (29% versus 17%). However, unlike mental illness, substance use disorders are more common in men than in women (20% versus 15%) (Figure 2).

How are non-elderly adults with mental and substance use disorders covered and how does prevalence vary by coverage?

Private insurance covers most non-elderly adults with mental illnesses and substance use disorders. Private insurance covers the majority of non-elderly adults with any mental illness (58%) and any substance use disorder (57%); combined, that’s more than 37 million people with either condition covered by private insurance. Although it only covers 18% of the non-elderly adult population, Medicaid covers 23% of people with mental illness and 21% of those with substance use disorder, or about 13, 9 million people (Figure 3).

Mental illness and substance use disorders are most common among non-elderly adults on Medicaid. In 2020, an estimated 29% of Medicaid enrollees have a mental illness, compared to 21% of privately insured and 20% of uninsured people. About one in five Medicaid recipients (21%) have a substance use disorder, similar to that of uninsured people (19%), but higher than that of privately insured people (16%). Additionally, Medicaid enrollees have the highest overall prevalence of moderate to severe mental disorders or substance use disorders. Together, 39% of Medicaid enrollees have a mental illness and/or substance use disorder, compared to 31% of those privately covered and uninsured. An estimated 11% of adults on Medicaid have both a mental illness and a substance use disorder, compared to 7% of those privately covered and 8% of those uninsured ( Figure 4).


Among non-elderly adults with moderate or severe mental illness or substance use disorder, those enrolled in Medicaid are more likely than those with private insurance to have chronic conditions and to report fair or poor health. There is a high comorbidity between mental conditions and chronic physical conditions, which increases with the severity of symptoms. The relationship is two-way, with physical conditions sometimes increasing the risk of mental disorders, and vice versa. Those enrolled in Medicaid with moderate to severe mental illness or substance use disorders are more likely to report chronic conditions than those with private coverage, and a higher proportion report two chronic conditions or more. Additionally, Medicaid-enrolled individuals with severe/moderate mental illness or substance use disorders report fair-to-poor health more than twice as often as privately insured individuals (36% and 13 %, respectively) (Figure 5).

What are the main issues to watch for the future?

As policymakers attempt to structure policy responses to address mental health and addictions needs, it is important to understand the coverage and characteristics of people experiencing these issues. At the state level, states are implementing a range of policies to address mental illness and substance use disorders, including policies to expand access through Medicaid. States will also be largely responsible for implementing the new ‘988’ hotline, including how sustainably funds this. At the federal level, bipartisan efforts have formed to address the mental health crisis, including mental health packages and a legislative agenda of the Addiction and Mental Health Task Force, as well as federal mental health parity oversight of insurers offenses. The Biden administration has announced its National drug control strategy to combat addiction and the opioid epidemic and Unit Agenda proposes to improve behavioral health workforce capacity, improve access to care in integrated settings, and expand insurer coverage requirements. The gaps in behavioral health care delivery are old and complex, but emerging initiatives seek to improve access and quality of services.