The approval of a controversial new drug for Alzheimer’s disease, Aduhelm, is shining a spotlight on mild cognitive impairment—problems with memory, attention, language, or other cognitive tasks that exceed changes expected with normal aging. After initially indicating that Aduhelm could be prescribed to anyone with dementia, the Food and Drug Administration now specifies that the prescription drug be given to individuals with mild cognitive impairment or early-stage Alzheimer’s, the groups in which the medication was studied. Yet this narrower recommendation raises questions. What does a diagnosis of mild cognitive impairment mean? Is Aduhelm appropriate for all people with mild cognitive impairment, or only some? And who should decide which patients qualify for treatment: dementia specialists or primary care physicians? Controversy surrounds Aduhelm because its effectiveness hasn’t been proved, its cost is high (an estimated $56,000 a year, not including expenses for imaging and monthly infusions), and its potential side effects …