About the National Survey on Drug Use and Health
Below are common questions on basic information about NSDUH.
Concerns About Trend Comparability
Below are common questions about trend comparability.
- What changes were made to 2021 NSDUH data to make it comparable to later years (e.g. 2022, 2023, etc.)?
- Why does SAMHSA caution against comparing estimates from 2021 and later years with estimates from prior years?
- Why does SAMHSA caution against comparing 2020 estimates with estimates from other years?
- Why does SAMHSA caution against comparing many 2015 estimates with estimates from prior years?
- Why can’t 2020 data be pooled with data from other years? What about 2015 data?
- When did NSDUH make the change from DSM-IV to DSM-5 for assessing mental health and substance use disorders?
- How have definitions of prescription drugs (including pain relievers and opioids) changed over time?
- When substate regional estimates are produced, are the regions the same each time?
Finding Commonly Requested Data Products
Below are common questions about finding commonly requested data products.
Details About Microdata and Survey Questions
Below are common questions about microdata and survey questions.
- Does NSDUH data differentiate between medical and recreational marijuana use?
- What is the smallest geographic unit available for analysis?
- How many counties were covered by the survey in recent years? How many substate regions have data available?
- Why do there appear to be missing sequential datasets in the restricted data?
Help With Analysis
Below are common questions for help with analysis.
- What is the difference between NSDUH public and restricted-use data?
- How can I decide which estimates are unreliable due to small sample size or other factors?
- How do I perform tests of statistical significance or calculate confidence intervals with NSDUH?
- Where can I find complete information on NSDUH survey methodology and design?
- Which file formats are available for the NSDUH public use files?
- What is the oldest data year available?
NSDUH Topic Coverage
Below are common questions about NSDUH topic coverage.
- Does NSDUH produce data on both illicit and prescribed fentanyl use?
- Does NSDUH collect information on carfentanyl, xylazine, or ayahuasca use?
- Does NSDUH collect data on people who have been denied treatment?
- Does NSDUH collect data about the utilization of mental health services by a specific program?
Questions About Published Tables
Below are common questions about published tables.
- Why are there differences in the 2021 estimates between the detailed tables released for 2021 and the detailed tables released for 2022?
- Why is it that sometimes the estimate for a group is suppressed while the estimate of a smaller subgroup is not suppressed?
- Can state-level NSDUH estimates be used to rank states?
- Why are state-level estimates on treatment outcomes based on only 2022 data in the 2021-2022 release?
- When NSDUH tables indicate that a certain number of people had a substance use disorder (SUD) in the past year, how is "past year" defined?
- How was the NSDUH weighted population created?
Questions about the Research Data Center (RDC)
Below are common questions about the Research Data Center (RDC).
- How much does it cost to gain access to restricted use data?
- What data sources are available from the SAMHSA Research Data Center (RDC)?
- What are SAMHSA’s criteria to grant access to restricted use data?
- What resources are SAMHSA providing to support access to restricted use data?
- How do I apply for restricted use data access?
- How fast can I expect to gain access to restricted data after submitting an application?
- What can I bring with me into the Research Data Center (RDC) data analysis room?
- What type of output from the Research Data Center (RDC) environment is allowed?