β-AARC: Cohort Study for the Identification of Blood-based Biomarkers in a Population With Subjective Cognitive Decline

"Cross sectional analyses The two main variables for the analysis will be: Values of biomarker concentrations in blood and their correlations with CSF biomarkers and the development of prodromal AD for the cognitively unimpaired SCD population. Other variables of interest for the study are, among others, risk factors, cognitive status, measurements of brain structure and function, mental health, chronic diseases, environmental exposures, age and sex.~Longitudinal analyses Longitudinal analyses will estimate the association between the intensity of the subjective complaint and the rate of progression between the diagnostic categories; The association of biomarkers, risk factors and other clinical variables with the rate of progression between the diagnostic categories; The association of cognitive and neuroimaging variables with the rate of progression between the diagnostic categories; The evolution of the complaint itself and its relation to the other variables described."