FIGURE 1.

Alzheimer's disease (AD) evolution. Presymtomatic, preclinical, and clinical periods. The diagram shows the evolution of a hypothetical AD case. The AD pathologic burden (neurofibrillary tangles and senile plaques) is represented in a rising line. The top of the figure express the AD evolution periods. The long preclinical period can be divided into pre‐symptomatic (only histological alterations) and true preclinical (positive AD biomarkers in cerebrospinal fluid or neuroimaging, without clinical manifestations). The AD clinical period is divided in the predementia state mild cognitive impairment (MCI) (gray stripe) and in the clinical dementia period. The years depicted must be considered standard ranges; moreover, the presymptomatic period could be probably >40 years in some cases, and the sporadic Alzheimer's disease dementia period could be from 3 months to 20 years. Taken from Bermejo‐Pareja, 2018 [2] with minor modifications