Watch The Forgetting: A Portrait of Alzheimer's (2004) : Full Movie Online Free Alzheimer's, a devastating disease that is the fourth leading cause of death for the elderly population, is a form of dementia that affects millions of Americans. It holds a terrible fate for those it strikes, but it is often most painful for family and friends of those diagnosed with it. This documentary, first aired on PBS, examines the disease as well as moving stories of those who have lost loved ones to the memory-stealing condition.