- "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
Alzheimer's disease is an ailment that is known to affect the elderly among the people of Earth, where victims would 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")