- "My father had a disease called Alzheimer's. It's similar in many respects to the condition that Doctor McKay is suffering from."
- ―Richard Woolsey[src]
Alzheimer's disease is an ailment that affects the elderly among the people of Earth; victims suffer from memory loss. Richard Woolsey's father had Alzheimer's. In 1998, SG-5 went on a mission to an unnamed planet, where they found a potential cure for the disease. This potential cure was brought back to Area 51. A similar, yet parasitic equivalent was found in the Pegasus Galaxy, known as Second Childhood. (SG1: "Touchstone", SGA: "The Shrine")