New research suggests impared memory isn’t the only indicator of the cognitive decline known as pre-Alzheimer’s. Scientists say lower performance on tests measuring story learning or retention and processing speed in motor tasks dependent on visual control, as well as symptoms of depression, predicted subsequent cognitive decline in a normal population.

"For a long time, researchers believed that memory alone was the only important factor in mild cognitive impairment," said the study’s lead author, S. Duke Han, Ph.D. "Our study is one of the first to suggest the importance of other factors in predicting this possible pre-Alzheimer’s condition."

Study participants underwent a battery of standard cognitive and psychosocial tests to assess mood, attention, visuospatial abilities, language facility, memory and intelligence.

Researchers say poor learning accompanied by either slower visuomotor processing speed or depressive symptoms were significantly related to later problems in cognition. For example, a lower performance on a learning test, paired with a lower score on the depression scale, predicted the development of mild cognitive impairment a year later with an accuracy of 80 to 100 percent in the test sample.

According to the Alzheimer’s Association, the disease currently impacts more than 5 million Americans.

Signs of Alzheimer’s include memory loss, difficulty solving problems, confusion with time or place, trouble understanding spatial relationships, poor judgment, withdrawal from work or social activities and changes in mood and personality.