Reading Ability as an Estimator of Premorbid Intelligence: Does It Remain Stable in Emergent Dementia?

The 6-year stability of reading performance was investigated in subjects who were normal at baseline but suspect for dementia at follow-up (MMSE score or = 15 IQ points). The decline of DART IQ was related to deterioration of semantic memory as reflected in verbal abstraction and category fluency. It is concluded that the DART remains a valid estimator of premorbid verbal intelligence in mild and questionable dementia. A formula is presented which can correct the underestimation on the basis of the MMSE score.