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NACCADRC

2026-04-27

Source: vignettes/NACCADRC.qmd

Overview

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.

NACCADRC includes data from:

Note some datasets that combine data from different sources have the prefix dropped (e.g. amyloidpetgaain, amyloidpetnpdka, fdgpetnpdka, mriqc, mrisbm, petqc, and taupetnpdka)

ADRC program components

(adapted from (Mormino et al. 2025))

  • Alzheimer’s Disease Research Centers (ADRCs): Individual centers throughout the United States, funded via a project grant by the National Institute on Aging (NIA). Each ADRC enrolls a Clinical Core cohort relevant for AD and related dementias (ADRD). Inclusion is determined based on center expertise.
  • National Alzheimer’s Coordinating Center (NACC): NACC is the centralized data repository for the ADRC program, and additionally provides infrastructure for collaboration and communication across sites. NACC is directed by Drs. Walter Kukull and Sarah Biber at the University of Washington.
  • National Centralized Repository for Alzheimer’s Disease and Related Dementias (NCRAD): NCRAD supports the ADRCs with a fluid biorepository, genome-wide panels, and standard blood collection procedures. NCRAD is directed by Dr. Tatiana Foroud at Indiana University.
  • Standardized, Centralized AD/ADRD Neuroimaging (SCAN): SCAN implements multi-site workflows for standardized acquisition and analysis of PET and MRI data across ADRC sites. The SCAN PET Core is led by Bill Jagust at University of California Berkeley and the SCAN MRI Core is led by Clifford Jack at Mayo.
  • The Laboratory of Neuroimaging (LONI): LONI acts as the repository for PET and MRI image data collected with SCAN standardized protocols across the ADRC sites. LONI is directed by Dr. Arthur Toga at the University of Southern California.
  • The Consortium for Clarity in ADRD Research Through Imaging (CLARiTI) (U01 AG082350) (Mormino et al. 2025) This initiative aims to strengthen the Alzheimer’s Disease Research Center (ADRC) program by providing standardized, comprehensive in vivo biomarker data to improve understanding of mixed pathologies in Alzheimer’s disease and related dementias (ADRD). Building on existing ADRC infrastructure, CLARiTI incorporates standardized imaging and plasma collection to characterize mixed pathologies and applies community‑engaged research methods to enhance diversity in ADRD research..

Installation

To install the package locally, run

install.packages("path/to/NACCADRC_73.20260410.1.tar.gz", repos = NULL, type = "source")

Package usage and key meta data

Code
# Load the NACCADRC package
library(NACCADRC)

# Loads specific data sets into the R environment
data(data_release_date, data_dictionary, file_manifest)

Package source data release date

The NACCADRC package contains a data stamped date of which the raw data was downloaded to build the package. For instance, the current package contains data that downloaded from the NACC as of 2026-04-10.

Code
# Data source downloaded date
data_release_date
#> [1] "2026-04-10"

Data dictionary

The separate data dictionaries provide by NACC have been merged into one data dictionary file (data_dictionary):

Code
head(data_dictionary, 6)
#> # A tibble: 6 × 15
#>   DataName      VariableName ShortDescriptor          Comment AllowableCodes Source Data Freeze variable…¹ `Data type` `Data source` `Variable Length`
#>   <chr>         <chr>        <chr>                    <chr>   <chr>          <chr>  <chr>                  <chr>       <chr>         <chr>            
#> 1 phc_biomarker NACCID       Participant ID           <NA>    <NA>           NACC_… <NA>                   <NA>        <NA>          <NA>             
#> 2 phc_biomarker NACCVNUM     Visit Number             <NA>    <NA>           NACC_… <NA>                   <NA>        <NA>          <NA>             
#> 3 phc_biomarker AB42_RAW     Raw AB42 Biomarker Leve… <NA>    <NA>           NACC_… <NA>                   <NA>        <NA>          <NA>             
#> 4 phc_biomarker PHC_AB42     Harmonized Z-Score for … <NA>    <NA>           NACC_… <NA>                   <NA>        <NA>          <NA>             
#> 5 phc_biomarker Tau_RAW      Raw Tau Biomarker Levels <NA>    <NA>           NACC_… <NA>                   <NA>        <NA>          <NA>             
#> 6 phc_biomarker PHC_Tau      Harmonized Z-Score for … <NA>    <NA>           NACC_… <NA>                   <NA>        <NA>          <NA>             
#> # ℹ abbreviated name: ¹​`Data Freeze variable name`
#> # ℹ 5 more variables: `Description / derivation` <chr>, Form <chr>, VariableType <chr>, DataType <chr>, `Source variable` <chr>

File manifest

A complete file manifest of all the source files used to build the package is also stored in the package (file_manifest):

Code
file_manifest %>%
  datatable(., paging = TRUE)
Beekly, Duane L, Erin M Ramos, William W Lee, Woodrow D Deitrich, Mary E Jacka, Joylee Wu, Janene L Hubbard, et al. 2007. “The National Alzheimer’s Coordinating Center (NACC) database: the uniform data set.” Alzheimer Disease & Associated Disorders 21 (3): 249–58.
Donohue, Michael C, Kedir Hussen, Oliver Langford, Richard Gallardo, Gustavo Jimenez-Maggiora, Paul S Aisen, and Alzheimer’s Disease Neuroimaging Initiative. 2026. “Alzheimer’s clinical research data via R packages: The alzverse.” Alzheimer’s & Dementia 22 (2): e71152. https://doi.org/10.1002/alz.71152.
Mormino, Elizabeth C, Sarah A Biber, Annalise Rahman-Filipiak, Konstantinos Arfanakis, Lindsay Clark, Jeffrey L Dage, John A Detre, et al. 2025. “The Consortium for Clarity in ADRD Research Through Imaging (CLARiTI).” Alzheimer’s & Dementia 21 (1): e14383.
R Core Team. 2025. R: A Language and Environment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing. https://www.R-project.org/.