DOI: 10.3886/icpsr06693.v2
title: National Comorbidity Survey: Baseline (NCS-1), 1990-1992
title: Version 2

description: The National Comorbidity Survey: Baseline (NCS-1) was a collaborative epidemiologic investigation designed to study the prevalence and correlates of DSM III-R disorders and patterns and correlates of service utilization for these disorders. The NCS-1 was the first survey to administer a structured psychiatric interview to a nationally representative sample. The survey was carried out in the early 1990s with a household sample of over 8,000 respondents. Subsamples of the original respondents completed the NCS-1 Part II survey and Tobacco Use Supplement. Diagnoses were based on a modified version of the Composite International Diagnostic Interview (the UM-CIDI), which was developed at the University of Michigan for the NCS-1. Drugs covered by this survey include alcohol, tobacco, sedatives, stimulants, tranquilizers, analgesics, inhalants, marijuana/hashish, cocaine, hallucinogens, heroin, nonmedical use of prescription drugs, and polysubstance use. Other items include demographic characteristics, personal and family history of substance use and abuse, substance abuse treatment, data on drug use including recency, frequency, and age at first use, problems resulting from the use of drugs, personal and family history of psychiatric problems, mental health treatment, symptoms of psychiatric disorders, mental health status, HIV risk behaviors, and physical health status.
description: Depending on the section(s) of the NCS-1 survey from which the variable(s) originated, one of four sampling weights must be selected and applied. The Part I and Part II weights (p1fwt and p2wtv3, respectively) are a combination of the various weights described in NCS-1 papers to adjust for differential household size and differential nonresponse and post-stratification. The Tobacco Use Supplement weight (tobacwt) is a rescaling of the Part I weight for analysis of tobacco supplement variables only. The Part II Tobacco Use Supplement weight (p2tobwt) is a rescaling of the Part II weight for analysis of combinations of Part II and Tobacco Supplement variables. Please refer to the Processor Notes in the codebook for details on determining the appropriate weight to use when analyzing a specific variable or combination of variables.
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: Performed consistency checks.; Created variable labels and/or value labels.; Standardized missing values.; Created online analysis version with question text.; Performed recodes and/or calculated derived variables.; Checked for undocumented or out-of-range codes..
description: Response Rates: The response rate was 82.6 percent.
description: Datasets: 
 
 DS0: Study-Level Files 
 DS1: NCS-1 Main Data 
 DS2: NCS-1 Diagnosis/Demographic Data 
 DS3: Merged Data Files for Online Analysis
description: face-to-face interview, telephone interview 
Users are reminded that NCS-1 Part I, Part II, and Tobacco Use Supplement variables are all contained in Part 1, the NCS-1 Main Data file. The DSM-III-R diagnosis and demographic variables are contained in Part 2, the NCS-1 Diagnosis/Demographic Data file.
 A restricted data file has been produced that contains state and county geography codes. This file is available from ICPSR. To obtain the restricted data file users must first submit a completed restricted data request form. Please read ICPSR's instructions about requesting restricted data. 
 For more information, visit the NCS Web site.
description: Persons aged 15 to 54 years in the noninstitutionalized civilian population in the 48 continuous United States.
description: Stratified, multistage area probability sample. The inclusion of respondents as young as 15 years, compared with the 18-year-old lower age limit found in most general population surveys, was based on an interest in minimizing recall bias of early-onset disorders. The exclusion of respondents aged older than 54 years was based on evidence from the Epidemiologic Catchment Area Study that active comorbidity between substance use disorders and nonsubstance psychiatric disorders is much lower among persons older than 54 years than among those aged 54 years and younger. The Part II NCS-1 survey was administered to a subsample of 5,877 respondents. The Tobacco Use Supplement was completed by a subsample of 4,414 respondents. The NCS-1 also includes a supplemental sample of students living in campus group housing and a nonrespondent survey.