NACCADRC is an R data package (R Core Team 2025; Donohue et al. 2026) containing data and R code for the National Alzheimer’s Coordinating Center (NACC) (Beekly et al. 2007) Alzheimer’s Disease Research Centers (ADRC) data. NACCADRC is a bundle of data, analysis code examples, and documentation. Data, including the R package are available from the NACC.
Installation
To install the package locally, run install.packages("path/to/NACCADRC_73.20260410.1.tar.gz", repos = NULL, type = "source").
Usage
Learn more about NACCADRC at Get Started page
NACC Data
Notes about NACC data:
Please refer to the NACC Researcher’s Guide to learn about how the data are structured.
Data dictionaries and other documentation:
NACC files include variables from the following data sets. Some of the variables have only been collected during certain versions of the data collection instruments. Please review these documents and take note of any changes to variables across versions.
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Researchers Data Dictionary - Uniform Data Set (UDS)
- Note the neuropsychological batteries have changed between versions of the UDS. Please take a look at the RDD-UDS and the crosswalk study that provides information about the battery changes across UDS versions.
- Additionally, note the neuropsychological test instructions, worksheets, and stimuli are all in password-protected documents. If you need to access these documents, the password is:
nacc8down - Calculations for several derived variables have been revised. See the Data Freeze (README) document for more information.
- Researchers Data Dictionary - Genetics (includes APOE) * Researchers Data Dictionary - Neuropathology Data Set * Researchers Data Dictionary - Imaging (for mixed protocol (non-SCAN compliant) MR and PET scans)
- Researchers Data Dictionary - SCAN MRI
- Researchers Data Dictionary - SCAN PET
- Researchers Data Dictionary - Mixed-Protocol PET
- Data Element Dictionary - LBD Module (Initial Visit) (Follow-Up Visit)
- Data Element Dictionary - FTLD Module (Initial Visit) (Follow Up Visit)
- Data Element Dictionary - CSF Biomarker Data * Note: We strongly caution use of CSF data for all analyses; ranges for amyloid beta and tau are scaled differently for each brand of kit used by various Centers.
- As a resource to investigators, NACC provides CSV files of all RDD-UDS, RDD-Neuropathology and RDD-Genetics variables and coding, linked in the respective sections under “Download Your Data Set: About Data Downloads” in the Researcher’s Guide.
- For additional documentation on each data type, please refer to the Forms and Documentation section of the NACC website.
Data use reminders:
- Submit ANY abstracts and publications using these data to NACC via the Publish with NACC Data page and review the Checklist for Authors. If you use the
NACCADRCR data package, please also cite (Donohue et al. 2026). - The data in the
NACCADRCR data package is non-commercial data. If your project goals shift to commercial goals, notifyconsnacc@uw.edu.
Funding
Work on this R package was funded by CLARiTI (NIH U01 AG082350). The NACC database is funded by NIA/NIH Grant U24 AG072122. SCAN was funded by NIA/NIH U24 AG067418. See naccdata.org for more information.