Imagine your spouse of 40 years has been missing for hours, when he finally comes home, he has no idea where he was or what he was doing. This can be a defining moment, when you know something is wrong. Alzheimer's disease gradually destroys a person's ability to reason, remember, imagine and learn. And over time, cognitive abilities -- like being able to process information, or have abstract reasoning and problem solving skills--significantly decrease, leaving patients unable to perform simple tasks and function on their own. While there is no cure, Alzheimer's disease doesn't have to mean the end of a patient's independence. Getting treatment early and staying active may allow patients to continue doing things they've always enjoyed.