The comparison of cognitive and functional performance in children and Alzheimer's disease supports the retrogenesis model.

The retrogenesis model states that the progression of brain aging and Alzheimer's disease (AD) deterioration proceeds inversely to human ontogenic acquisition patterns. Our aim was to assess if the progressive decline of cognitive abilities and functional capacity in AD follows an inverse sequence of acquisition compared to normal developmental patterns. One hundred eighty one children ranging in age from 4 to 12 years and 148 adults (cognitively normal, subjects with mild cognitive impairment, and mild-moderately severe AD) were assessed with the same cognitive and functional tools. The statistical analyses showed a progressive and inverse distribution on cognitive, functional, and mental age scores when comparing results of children classified by chronological age and patients by dementia staging. The pattern of cognitive acquisition in children showed a progressive development of overall cognitive function along all age ranges, in addition to a simultaneous acquisition of instrumental and basic daily living activities in the functional domain. AD patients showed a progressive decline in cognitive and functional domains, which concurs with the sequence of impairment reported in this dementia. Our findings provide support to the inverse and progressive pattern of functional and cognitive decline observed in AD patients compared to the developmental acquisition of these capacities in children, as stated by the retrogenesis model. Nonetheless, certain differences should be considered when comparing the sequence of acquisition during ontogenic development with that of progressive loss during the course of AD. Retrogenesis may account for the progressive loss of neocortical-related functions in AD.