DOI: 10.3886/icpsr28581.v2
title: National Comorbidity Survey: Adolescent Supplement (NCS-A), 2001-2004
title: Version 2

description: 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.
description: 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.
description: 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..
description: 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.
description: Datasets: 
					
						DS0: Study-Level Files
						DS1: Adolescent Household and School Respondents
						DS2: Parent Self-Administered Questionnaire (PSAQ)
						DS3: Parent Self-Administered Questionnaire (PSAQ) and Telephone Interview (PIP)
						DS4: Diagnostic Variables From Both Adolescents and Parents
						DS5: K-BIT Scores
						DS6: Raw K-BIT Data
description: computer-assisted personal interview (CAPI), computer-assisted telephone interview (CATI), telephone interview
					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.
description: 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.