The primary instrument used in ADNI for evaluating SCD is the everyday congition scale (eCOG), which is collected in both self-report and informant-report formats. The 39-item eCOG was used for the ADNIGO, ADNI2, and ADNI3 phases of the study, while the newer 12-item version is currently in use for ADNI4. The data can be found on the LONI IDA.