Ronald Reagan's son suggests in a new book that his father suffered from the beginning stages of Alzheimer's disease while he was still in the White House.
The memoir quotes excerpts from Ron Reagan's book, My Father At 100, published by Viking.
Reagan's son writes that he believes his father would have left office before his second term ended in 1989 had the disease been diagnosed then.
"Had the diagnosis been made in, say 1987, would he have stepped down? I believe he would have," his son says.
Ronald Reagan was diagnosed with Alzheimer's in 1994.