Many older people wonder if forgetting names or misplacing the car keys means they may have early signs of Alzheimer’s. While forgetfulness is a hallmark feature of the disease, other symptoms may occur before memory loss. A new study in the journal Neurology found that depression and other behavioral changes may occur before memory loss in people who go on to develop the disease.
While researchers had observed that certain behaviors, such as appetite loss, irritability, apathy, and depression, can accompany Alzheimer’s, they were unsure exactly when in the disease process these symptoms surface. In a study at Washington University in St. Louis, researchers looked at data from 2,416 people ages 50 and older. Participants were evaluated for seven years using extensive tests assessing mental and psychological health. All of the study participants had normal cognition at the start of the study, but 1,218 went on to develop dementia.
The researchers found that study participants who were eventually diagnosed with Alzheimer’s were more likely than those who were not to present with mood and behavioral changes first. After four years, 30 percent of participants who were diagnosed with Alzheimer’s were also depressed.
Delusions also occurred as an early sign. The people who went on to develop Alzheimer’s were more than 12 times as likely to have delusions as their healthy counterparts.
This does not mean that mood signs can be used as markers to diagnose the disease, said the study authors. For example, 15 percent of those who developed depression four years into the study did not go on to develop Alzheimer’s. More research is still needed to better understand how behavioral and mood changes are connected to the disease process.