Major Depression

Definitions

Major depression is one of the most common mental disorders in the United States. For some individuals, major depression can result in severe impairments that interfere with or limit one’s ability to carry out major life activities.

Additional information can be found on the NIMH Health Topics page on Depression.

The past year prevalence data presented here for major depressive episode are from the 2021 National Survey on Drug Use and Health  (NSDUH). The NSDUH study definition of major depressive episode is based mainly on the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5):

• A period of at least two weeks when a person experienced a depressed mood or loss of interest or pleasure in daily activities, and had a majority of specified symptoms, such as problems with sleep, eating, energy, concentration, or self-worth.
• No exclusions were made for major depressive episode symptoms caused by medical illness, substance use disorders, or medication.

Prevalence of Major Depressive Episode Among Adults

• Figure 1 shows the past year prevalence of major depressive episode among U.S. adults aged 18 or older in 2021.
  • An estimated 21.0 million adults in the United States had at least one major depressive episode. This number represented 8.3% of all U.S. adults.
  • The prevalence of major depressive episode was higher among adult females (10.3%) compared to males (6.2%).
  • The prevalence of adults with a major depressive episode was highest among individuals aged 18-25 (18.6%).
  • The prevalence of major depressive episode was highest among those who report having multiple (two or more) races (13.9%).

Figure 1

Major Depressive Episode with Impairment Among Adults

• In 2021, an estimated 14.5 million U.S. adults aged 18 or older had at least one major depressive episode with severe impairment in the past year. This number represented 5.7% of all U.S. adults.

Treatment of Major Depressive Episode Among Adults

• In 2021, an estimated 61.0% U.S. adults aged 18 or older with major depressive episode received treatment in the past year.
• Among those individuals with major depressive episode with severe impairment, an estimated 74.8% received treatment in the past year.

Prevalence of Major Depressive Episode Among Adolescents

• Figure 2 shows the past year prevalence of major depressive episode among U.S. adolescents in 2021.
  • An estimated 5.0 million adolescents aged 12 to 17 in the United States had at least one major depressive episode. This number represented 20.1% of the U.S. population aged 12 to 17.
  • The prevalence of major depressive episode was higher among adolescent females (29.2%) compared to males (11.5%).
  • The prevalence of major depressive episode was highest among adolescents reporting two or more races (27.2%).

Figure 2

Major Depressive Episode with Impairment Among Adolescents

• In 2021, an estimated 3.7 million adolescents aged 12 to 17 in the United States had at least one major depressive episode with severe impairment in the past year. This number represented 14.7% of the U.S. population aged 12 to 17.

Treatment of Major Depressive Episode Among Adolescents

• In 2021, an estimated 40.6% of U.S. adolescents with major depressive episode received treatment in the past year.
• Among adolescents with major depressive episode with severe impairment, an estimated 44.2% received treatment in the past year.

Data Sources

Substance Abuse and Mental Health Services Administration. (2022). Key substance use and mental health indicators in the United States: Results from the 2021 National Survey on Drug Use and Health (HHS Publication No. PEP22-07-01-005, NSDUH Series H-57). Rockville, MD: Center for Behavioral Health Statistics and Quality, Substance Abuse and Mental Health Services Administration. Retrieved from https://www.samhsa.gov/data/report/2021-nsduh-annual-national-report .

Statistical Methods and Measurement Caveats

Please see the 2021 National Survey on Drug Use and Health Methodological Summary and Definitions report  and the 2021 NSDUH Frequently Asked Questions page  for information on how these data were collected and calculated. A few specific caveats are noted below.

Diagnostic Assessment:

• For the NSDUH survey — no exclusions were made for major depressive episode symptoms caused by medical illness, substance use disorders, or medication.
• For the NSDUH survey, methodology developed prior to the 2013 publication of the current DSM-5 was used to facilitate year-to-year comparisons.
• The adult and adolescent questions were adapted from the depression module in the National Comorbidity Survey Replication (NCS-R). Revisions to the questions in the modules were made primarily to reduce their length and to modify the NCS-R questions, which are interviewer-administered, to the audio computer-assisted self-interviewing (ACASI) format used in NSDUH. In addition, some revisions, based on cognitive testing, were made to improve comprehension. Furthermore, even though titles similar to those used in the NCS-R were used for the NSDUH modules, the results of these items may not be directly comparable. This is mainly due to differing modes of administration in each survey (ACASI in NSDUH vs. computer-assisted personal interviewing in NCS-R), revisions to wording necessary to maintain the logical processes of the ACASI environment, and possible context effects resulting from deleting questions not explicitly pertinent to major depression.
• Some questions in the adult depression module differ slightly from questions in the adolescent depression module; as such, major depressive episode data for adults aged 18 or older should not be compared to or combined with major depressive episode data for youths aged 12 to 17.
• The Sheehan Disability Scale (SDS) was used to assess the impact of major depressive episode on a person’s life. The SDS is a brief self-report tool with ratings from 0 to 10 (with 10 being the highest) for the level of impairment caused by the disorder in each of four role domains: home management, work, close relationships with others, and social life. A rating of ≥7 in at least one domain is considered to be severe impairment. Respondents were excluded if SDS role impairment severity was unknown, or if particular activities listed in the SDS were not applicable. For SDS level of impairment, the role domains for adolescents aged 12 to 17 were slightly modified from those for adults to be made age appropriate.

Population:

• The entirety of NSDUH respondents for the major depressive episode estimates is the civilian, non-institutionalized population aged 12-17 (adolescents) and 18 years old or older (adults) residing within the United States.
• The survey covers residents of households (persons living in houses/townhouses, apartments, condominiums; civilians living in housing on military bases, etc.) and persons in non-institutional group quarters (e.g., shelters, rooming/boarding houses, college dormitories, migratory workers' camps, and halfway houses).
• The survey does not cover persons who, for the entire year, had no fixed address (e.g., homeless and/or transient persons not in shelters); were on active military duty; or who resided in institutional group quarters (e.g., correctional facilities, nursing homes, mental institutions, long-term hospitals).
• Data regarding sex of the respondent was assessed using male and female categories only. Gender identity information was not collected in the survey.

Interview Response and Completion:

• In 2021, 54.1% of the selected NSDUH sample (participants ages 12+) did not complete the interview.
• Reasons for non-response to interviewing include: refusal to participate (27.6%); respondent unavailable or no one at home (23.6%); and other reasons such as physical/mental incompetence or language barriers (2.9%).
• Adults and adolescents with major depressive episode may disproportionately fall into these non-response categories. While NSDUH weighting includes non-response adjustments to reduce bias, these adjustments may not fully account for differential non-response by mental illness status.

Data Suppression:

• For some groups, data are not reported due to low precision. Data may be suppressed in the above charts if the data do not meet acceptable ranges for prevalence estimates, standard error estimates, and sample size.

Background on the 2021 NSDUH and the COVID-19 Pandemic:

• Due to COVID-19, data collection methods for the 2021 NSDUH differed from previous years.
  • The 2021 NSDUH used multimode (both in-person and virtual) data collection procedures that were first implemented in the fourth quarter of the 2020 NSDUH.
  • Overall, 54.6% of interviews were completed via the web, and 45.4% were completed in person.
• 2021 NSDUH estimates are not comparable with estimates from prior years given the use of multimode data collection procedures throughout the entire year and the rate of non-response, per SAMHSA methodological investigations .
• Estimates based on web interviews are different from estimates based on in-person interviews.
  • The demographics (e.g., gender, race, education) of people responding to web interviews differed from people answering in-person.
  • In-person respondents were also more likely to report use of certain substances and were more likely to report experiencing mental health issues.

Last Updated: July 2023