Does Bush Have Presenile Dementia?

In a letter to Atlantic Monthly Joseph Price, M.D. made this observation about President Bush:

"Slowly developing cognitive deficits, as demonstrated so clearly by the President [sic], can represent only one diagnosis, and that is 'presenile dementia'! Presenile dementia is best described to nonmedical persons as a fairly typical Alzheimer's situation that develops significantly earlier in life, well before what is usually considered old age."