Find Data

Most datasets in NAHDAP are primary data collected from surveys and interviews or obtained from administrative databases. NAHDAP preserves and disseminates them because they have value for "secondary analysis" - that is, reexamining existing data to reproduce original findings, address new questions, or employ new analytic methods.

Browse for Data

Data Access Using the VDE

Search Tips for Datasets

  • Our search indexes the full documentation for datasets, including descriptions of the variables.
  • You can search for multiple keywords:
    income health china
  • Use quotes to look for a phrase. (I.e., words in that precise order)
    "income distribution"
  • All studies are described using terms from the ICPSR Subject Thesaurus; these terms will appear as "Subject" filters on the left side of the results page.

Access to Data

Since NAHDAP is sponsored by the National Institute on Drug Abuse (NIDA), a federal agency, users obtain data from NAHDAP at no charge. To access data files, users must login to ICPSR with an ICPSR MyData account or an existing Google or Facebook account.

Restricted-Use Data

Please note that approximately 25% of NAHDAP's studies contain confidential data and are not available for Web download. Instructions on how to obtain those datasets are provided at the top of the study home page under "Access Notes." You will be required to provide Institutional Review Board (IRB) approval or exemption for your project.

For more information about access to restricted-use data, see Access to Restricted-Use Data. Also view the Find and Apply for Access to Restricted-Use Data Using Secure Dissemination (PDF) and the Data Access Using the VDE (PDF) to see step by step instructions and read answers to commonly asked questions.

ICPSR Member-Only Data

Some data listed on the NAHDAP website are available only to persons at ICPSR member institutions.


In almost all cases, documentation files, such as codebooks, questionnaires, and user guides, are freely available and do not require authentication.

Additional Data Resources

Free Statistical Software