What precedes memory loss

Depression and behavioral changes may occur before memory declines in people who will go on to develop Alzheimer's disease, according to new research in Neurology.

Researchers have known that many people with Alzheimer's experience depression, irritability, apathy and appetite loss but had not recognized how early these symptoms appear. Pinpointing the origins of these symptoms could be important to fully understanding Alzheimer's effects on the brain and finding ways to counteract them.

All of the participants were cognitively normal at the start, but over the course of the study, 1,218 of them developed dementia. Those who developed dementia during the study were more likely to have mood and behavioral changes first. For example, four years into the study, 30 percent of those who would go on to develop dementia had developed depression. In comparison, after the same period of time, only 15 percent of those who did not develop dementia during the study had become depressed. In addition, those who would go on to develop dementia were more than 12 times as likely to have delusions than those who did not develop dementia.