US President and Republican presidential candidate Ronald Reagan addresses the Republican National Convention (RNC) in Dallas on August 23, 1984. (Photo credit should read /AFP/Getty Images) File photo of President Ronald Reagan. (credit: AFP/Getty Images)

WASHINGTON (CBS DC) — A new study links former President Ronald Reagan’s public speech patterns and mannerisms to the early onset and development of dementia and Alzheimer’s.

Published in the Journal of Alzheimer’s Disease, researchers from Arizona State University tested methods for early detection by analyzing the speech patterns of the late U.S. president who was diagnosed with Alzheimer’s in 1994 and died in 2004. The researchers found that Reagan exhibited subtle changes in his speaking patterns while he was in office between 1981 and 1989.

Researchers Dr. Visar Berisha and Dr. Julie Liss found that Reagan’s speech included early signs of Alzheimer’s and dementia that increased toward the end of his time in office. The algorithm used to detect imperceptible cognitive decline assessed transcripts for all 46 news conferences held in comparison to 101 sessions by President George H.W. Bush during his own later term.

Berisha told Yahoo Health he was surprised how quickly changes were present in Reagan’s speech patterns.

“Others have shown that changes in writing complexity can evolve over very long intervals — tens of years,” he told Yahoo. “It was surprising that, by analyzing discourse rather than writing samples, similar changes were detectable over the course of two presidential terms.”

Reagan, who became the oldest elected president, was subject to critics who suggested his sometimes absent-minded behavior, contradictory statements and repeated forgetting of names was linked to dementia while he was in office. Although doctors and key aides reiterated to The New York Times they detected no changes in his mental health while he was president.

Reagan himself told The Times in June 1980 that he “never felt better” and that he wouldn’t seek office if he “had any feeling at all that [his] capabilities had been reduced before a second term came… I would walk away. By the same token I would step down.”

The researchers compared Reagan and then-Vice President George H.W. Bush’s speaking patterns because both men were comparable in age and both had long-term transcript information available to the public. Reagan was 69 when he became president and Bush was 64 at the time.

The “highly innovative” methods used were intended to help “further clarify the extent to which spoken-word changes are associated with normal aging or predictive of subsequent progression to the clinical stages of Alzheimer’s disease,” Dr. Eric Reiman, director of the Banner Alzheimer’s Institute in Phoenix, told The Times.

Use of repetitive words and replacing specific nouns with terms like “thing” increased toward the end of Reagan’s presidency, and his use of unique words also declined. Bush, who doesn’t have a known Alzheimer’s diagnosis, exhibited no change in speaking patterns during his time as president.

The early detection of Alzheimer’s is crucial in tailoring future treatments for the cognitive decline caused by the disease.

“It seems that the future treatments are going to be effective in people where the disease can be detected very early,” Alzheimer’s disease expert Dr. Oscar Lopez, a professor of neurology and psychiatry at the University of Pittsburgh who was not involved in the new study, told Yahoo Health.

The researchers said they are “cautiously optimistic” a cure is near for Alzheimer’s and the analysis of Reagan’s day-to-day interactions help analyze the “imperceptible” changes effecting one’s speech patterns.

“Our goal is that one day we can develop health applications that automatically analyze speech and language biomarkers for disease onset or progression,” said Berisha.