Dig into how Alzheimer’s disease affects your brain and cognitive abilities, and what makes the disorder so hard to treat. Around the world, millions of people have Alzheimer’s disease, a debilitating brain disorder that gradually destroys a person’s memory and other cognitive abilities. While doctors have studied Alzheimer’s for decades, conducting hundreds of clinical trials, there is still no effective preventive treatment or cure. So, why is Alzheimer’s disease so difficult to treat? Krishna Sudhir investigates.Lesson by Krishna Sudhir, directed by Rowena Sheehan.