Worsening anxiety may be an early indicator of Alzheimer’s disease in older adults. A recently published study suggests there is a link between higher anxiety and the buildup of protein clumps in the brain that underlies Alzheimer’s disease.

Researchers studied the relationship between depression and the protein clumps in 270 people between the ages of 62 and 90. Known as amyloid beta, the pieces stick together and trigger the brain degeneration that leads to Alzheimer’s disease.

The scientists looked at symptoms that factor into depression, including anxiety, sadness and loss of interest in activities. They found anxiety symptoms increased over time among people with higher levels of amyloid beta in their brains. That, they said, suggests anxiety could be a sign of Alzheimer’s disease that shows itself before cognitive impairment sets in.

Using data from Harvard University’s Aging Brain Study, researchers at Brigham and Women’s Hospital in Boston gave the study participants baseline imaging scans commonly used in Alzheimer’s disease studies. They also administered a test that detects depression in older adults. The test scores for a five-year period were evaluated for three groups is depression symptoms, including apathy, severe dissatisfaction and anxiety. Those with higher amyloid beta levels in the brain also showed increasingly anxiety symptoms over time.

The team said more study is needed to establish anxiety as an early indicator of Alzheimer’s disease. If that association exists, anxiety could become a way to identify Alzheimer’s patients earlier and potentially slow down, treat or prevent the disease.