A new study suggests that the constantly revised definition that characterizes mild cognitive impairment may make Alzheimer's diagnosis harder to confirm, according to Reuters.

The source reports that initially, "mild cognitive impairment" was a condition characterized as having memory problems that lead to minor memory issues but not being so significant that they adversely affected individuals' everyday activities. However, over time, that definition shifted to include more people.

"There's been a lot of controversy … about the whole classification called mild cognitive impairment," Peter Whitehouse, study researcher and a geriatric neurologist at the Case Western Reserve University School of Medicine, told Reuters. "The major issue since the beginning [has been] defining its boundaries."

Creighton Phelps, head of the Alzheimer's Disease Centers Program at the National institute of Aging, told the news source that mild cognitive impairment needs to be better defined, as too many people with the condition are being lumped in with those suffering from Alzheimer's, which is a more severe condition. He added that while mild cognitive impairment can be challenging to deal with, the effects are not such that they interfere with one's overall quality of life.