Is it normal aging, Alzheimer's, or another dementia? Two of three Americans will experience cognitive impairment by the age of 70. But is it natural age-related forgetfulness, or the early indication of Alzheimer's Disease or other types of dementia? How worried should older people--or their families and friends--be about their memory loss? And what happens next? Kenneth Frumkin, PhD, MD, recently retired from a 36-year medical...