High Blood Pressure Causes Mental Decline

From the WebMD Archives

Dec. 15, 1999 (Atlanta) -- French researchers say there may be another good reason to keep "the silent killer" in check. After studying more than 1,300 elderly people in western France, they conclude high blood pressure has a long-term negative effect on mental function. The good news, they say, is that maintaining control of blood pressure with medications appears to considerably lower the risk of mental decline.

The four-year study compared scores on a mental evaluation test in a group of elderly people with varying degrees of cardiovascular health. They included "normotensive" individuals (no high blood pressure), those with hypertension controlled with medications, and a group with untreated high blood pressure.

The researchers found the odds of mental decline correlated directly with blood pressure status, such that those with untreated high blood pressure were four times more likely to suffer the problem than those with normal blood pressure. Taking blood pressure medications seemed to cut the risk in all situations, but the researchers found patients benefited most when the drugs were able to keep blood pressures at a normal level.

That's an important point to remember, says Charles DeCarli, MD, director of the Alzheimer's Disease Center at the University of Kansas in Kansas City, Mo. "If you have untreated high blood pressure you're much worse off. But with treatment, it has to be effective." Otherwise, DeCarli says, a false sense of security takes hold -- and that can lead to a stroke. His recommendation: have blood pressure checked regularly, even if you are "controlled" on medication.

DeCarli says the study extends what doctors already know about the mental effects of high blood pressure. "There are three other studies ... all showing kind of the same thing over a much longer duration," he says "What's unique here is that the decline occurred in four years."

And it was a substantial decline at that, DeCarli says, with the scores for those with untreated high blood pressure dropping to levels that put them at risk for dementia. He says it raises the issue of whether high blood pressure somehow primes people for the development of Alzheimer's disease. "High blood pressure is probably another risk factor for late-life dementia," DeCarli says. "The importance of this is that we can control blood pressure much better than any other risk factor for Alzheimer's disease."

Given the controllability of high blood pressure -- and its relation to dementia -- family members caring for someone elderly may want to consider a few early signs of mental decline. Audrey Cochran, RN, MS, a specialist in caring of the elderly in Bakersfield, Calif., says repetition is a key one. "Repeating the same information in a 20-minute time span," she says -- such as asking a person's name over and over.

Another sign is the use of pronouns as identifiers for names or objects that are familiar. Cochran says an example would be to use a series of "he's" and "she's" to describe family members.

But she cautions that it's unfair and inaccurate to paste the "absent-minded" label on all elderly people. "When you look at people 85 and older, one-quarter of them have dementia, but three-quarters of them don't. But we view all older persons as not being able to remember things."

Vital Information:

  • Uncontrolled high blood pressure causes mental decline in elderly patients.
  • Taking blood pressure medications cuts the risk of mental decline, and is most effective when blood pressure is maintained at a normal level.
  • Mental decline was so substantial in some patients, they were at high risk for developing dementia, which can be an early symptom of Alzheimer's disease.