National Comorbidity Survey: Adolescent Supplement (NCS-A), 2001-2004 (ICPSR 28581)

Principal Investigator(s): Kessler, Ronald C., Harvard Medical School. Department of Health Care Policy


The National Comorbidity Survey Replication Adolescent Supplement (NCS-A) was designed to estimate the lifetime-to-date and current prevalence, age-of-onset distributions, course, and comorbidity of DSM-IV disorders in the child and adolescent years of life among adolescents in the United States; to identify risk and protective factors for the onset and persistence of these disorders; to describe patterns and correlates of service use for these disorders; and to lay the groundwork for subsequent follow-up studies that can be used to identify early expressions of adult mental disorders.

The core NCS-A interview schedule was an adaptation of the World Health Organization Composite International Diagnostic Interview (CIDI). NCS-A also administered the non-verbal subtest (Matrices subtest) of the Kaufman Brief Intelligence Test (K-BIT).

In addition to interviewing adolescents, information was collected from a parent or a parent surrogate to obtain an additional perspective on the adolescent's mental health and its correlates. Information from parents focused on the five adolescent disorders for which previous methodological research has most consistently shown that parental reports are important for making diagnoses: attention-deficit/hyperactivity disorder, conduct disorder, oppositional defiant disorder, major depressive episode, and dysthymic disorder.

Demographic information collected by NCS-A includes age, citizenship status, country of birth, criminal history, ethnicity, grandparents' country of birth, language(s) spoken in the home, parents' country of birth, race, religion, and sex.

The data collection contains six data files: (1) data for the adolescent household and school respondents; (2) data for the parents who responded to the long self-administered questionnaire; (3) data for the parents who responded to both the long self-administered questionnaire and short telephone interview; (4) diagnostic variables derived from the data collected from the adolescents and parents; (5) K-BIT scores normed to the NCS-A adolescent sample; and (6) raw K-BIT data.

Access Notes

  • One or more files in this data collection have special restrictions ; consult the restrictions note to learn more. You can apply online for access to the restricted-use data. A login is required to apply.

    The data files are restricted from general dissemination for reasons of confidentiality. Users interested in obtaining these data must complete an Agreement for the Use of Confidential Data, specify the reasons for the request, and obtain IRB approval or notice of exemption for their research. Apply for access to these data through the ICPSR restricted data contract portal which can be accessed via the study home page.

    Any public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.


DS0:  Study-Level Files
DS1:  Adolescent Household and School Respondents - Download All Files (387.742 MB) large file

ASCII + SAS Setup    SPSS Setup    Stata Setup   
DS2:  Parent Self-Administered Questionnaire (PSAQ) - Download All Files (90.736 MB)

ASCII + SAS Setup    SPSS Setup    Stata Setup   
DS3:  Parent Self-Administered Questionnaire (PSAQ) and Telephone Interview (PIP) - Download All Files (31.138 MB)

ASCII + SAS Setup    SPSS Setup    Stata Setup   
DS4:  Diagnostic Variables From Both Adolescents and Parents - Download All Files (18.596 MB)

ASCII + SAS Setup    SPSS Setup    Stata Setup   
DS5:  K-BIT Scores - Download All Files (19.663 MB)

ASCII + SAS Setup    SPSS Setup    Stata Setup   
DS6:  Raw K-BIT Data - Download All Files (286.935 MB) large file

ASCII + SAS Setup    SPSS Setup    Stata Setup   

Study Description


Kessler, Ronald C. National Comorbidity Survey: Adolescent Supplement (NCS-A), 2001-2004. ICPSR28581-v6. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2017-01-18.

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This study was funded by:

  • United States Department of Health and Human Services. National Institutes of Health. National Institute of Mental Health (U01-MH60220)
  • United States Department of Health and Human Services. National Institutes of Health. National Institute on Drug Abuse (R01-DA12058-05)
  • United States Department of Health and Human Services. Substance Abuse and Mental Health Services Administration
  • Robert Wood Johnson Foundation (Grant 044780)
  • John W. Alden Trust

Scope of Study

Subject Terms:    adolescents, health services utilization, intelligence, mental disorders, mental health, mental health services, parents, psychiatric services, young adults

Geographic Coverage:    United States

Time Period:   

  • 2001-02--2004-01

Date of Collection:   

  • 2001-02--2004-01

Unit of Observation:    individual

Data Type(s):    survey data

Data Collection Notes:

The technical documentation includes a ZIP archive with the diagnostic scoring algorithms. Each of the 31 documents in the archive (not counting the "read me" file) is provided in two formats: Word (.doc) and PDF. The Word files are the original files provided by the principal investigator. ICPSR generated the PDF files from the Word files.

The Codebook for Dataset 1 (Adolescent Household and School Respondents) is provided in two formats: PDF and HTML. The latter is supplied as a series of HTML files in a separate ZIP archive. The file named Contents.html in the ZIP archive is the "homepage" with links to the other HTML files.

The technical documentation for Dataset 6 (Raw K-BIT Data) includes a ZIP archive consisting of PDF files with relevant sections of the K-BIT manual and easel. ICPSR generated these PDF files from original paper documents but did not OCR the PDF files. Consequently, the files are not searchable.

ICPSR generated the SAS, SPSS, and Stata setups and the ASCII, SPSS, and Stata versions of the data from the original SAS files provided by the principal investigator. The SAS special missing value codes D and R in the SAS files were recoded in the ASCII and SPSS data files: D was recoded to 8, 98, 998, or 9998 depending on the size of the variable, and R was recoded to 9, 99, 999, or 9999. The missing value denoted by a dot (.) in the SAS and SPSS data files is represented as a blank field in the ASCII data files.

Only the SAS data files have value labels for the top and bottom codes (e.g., "20 or more" and "5 and under"). The SPSS and Stata data files and the SAS, SPSS and Stata setups do not have value labels for them.


Sample:    NCS-A was originally designed to sample adolescents residing in the households that participated in the National Comorbidity Survey Replication (NCS-R). However, the number of such youths was too small to generate the target sample of 10,000 respondents. Consequently, the households sample was supplemented by adding a school-based sample, leading to a dual frame design. One sample was recruited from the NCS-R households and the other from a representative sample of schools in the same communities as the NCS-R households. All schools (public and private, schools for gifted children, therapeutic schools, etc.) were included in their true population proportions. A stratified probability sample of students was selected from each school to participate in the survey.

Weight:    The data contain weights that account for within household probability of selection and for residual discrepancies between the sample and population on a wide range of census sociodemographic and geographic variables. Please refer to the user guide for information about the appropriate use of the weights.

Mode of Data Collection:    computer-assisted personal interview (CAPI), computer-assisted telephone interview (CATI), telephone interview

Response Rates:   

The response rate for adolescents in the household sample was 74.7 percent, yielding 9,244 interviews.

The response rate for adolescents in the school sample was 85.9 percent, yielding 904 interviews.

Extent of Processing:   ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Checked for undocumented or out-of-range codes.


Original ICPSR Release:   2011-07-27

Version History:

  • 2017-01-18 The K-BIT scores and raw data were added as Datasets 5 and 6.
  • 2016-07-29 (1) A Zip archive with the diagnostic scoring algorithms was added to the data collection. (2) Descriptions of the values for the variable REGION (Census Region) in Dataset 1 (Adolescent Household and School Respondents) were added to the technical documentation and value labels for REGION were added to the setups and SAS, Stata and SPSS data files.
  • 2013-08-28 Variable RESPGENDER (Respondent's Gender) in Dataset 1 (Adolescent Household and School Respondents) has been corrected. The previous version of this variable had incorrect values for 1,034 cases.
  • 2011-10-24 The setup files and documentation were added to the restricted release. Those files were already available through the public release.
  • 2011-10-20 The Stata setup and ready-to-go files and the tab-delimited files were released.
  • 2011-10-12 The HTML codebook was changed to be available for public use. Also, the statistical files were replaced because the previous version of the data contained incorrect decimal corrections across statistical packages. The SAS and Stata files were changed so that the original special missing value coding was not lost.

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