"Our nation certainly is ready to get deadly serious about this deadly disease," she told the Senate Special Committee on Aging.
She has a personal stake. "My beloved husband John suffers Alzheimer's," she said. "He is not in very good shape at present."
O'Connor stepped down as the first female Supreme Court justice in 2005 to move her husband to an assisted care center in Phoenix, near two of their children. Intensely private, she has said little until now of the family's experience except that.
According to a television news report in November, O'Connor's husbandand lives at the same assisted living center as him.
The retired justice wasn't jealous about the relationship and was pleased that her husband is comfortable at the center, the couple's son, Scott O'Connor, told KPNX in Phoenix in a broadcast that aired in November.
"Mom was thrilled that dad was relaxed and happy," Scott O'Connor said.
On Wednesday, O'Connor congratulated Congress for passing legislation that would ban discrimination based on genetic testing for a broad range of diseases, including Alzheimer's. "My own sons I have not wanted to go be tested ... out of fear they would be ineligible for insurance," she said.
More than 5 million Americans are living with Alzheimer's disease. The number is poised to skyrocket, with 16 million people forecast to have the mind-destroying illness by 2050. Today's treatments only temporarily alleviate symptoms. Already, the Alzheimer's Association estimates that 10 million people share the overwhelming task of caring for a relative or friend with it.
"I suspect that you will not hear from many of my fellow caregivers directly ... simply because they do not have the resources to take time away from their loved ones in order to come before you," O'Connor said in her prepared testimony.
Against that somber backdrop, a group of scientists, former politicians and well-known names like O'Connor have teamed up to create what they call a "national strategy" to jumpstart efforts to speed research into new Alzheimer's treatments and improve help for caregivers.
The so-called Alzheimer's Study Group won't have its report ready until next year, but began pushing lawmakers Wednesday to start thinking about the needed investment despite tight economic times. Public funding for Alzheimer's has been stagnant for five years, O'Connor noted.
"You will never meet an Alzheimer's survivor - there are none," former House Speaker Newt Gingrich, who co-founded the group, said in his testimony.