A new study has produced information suggesting that there could be an association between anxiety and Alzheimer’s disease (AD). The connection was found between elevated amyloid beta levels and increased anxiety symptoms. The findings back up the hypothesis that neuropsychiatric symptoms could be an early representation of Alzheimer’s disease in older adults.
Alzheimer’s disease causes the decline of cognitive function and makes it challenging to carry out simple daily activities. Past studies have suggested that other neuropsychiatric symptoms such as depression may be predictors of the disease’s progression during its “preclinical” phase. This phase can occur more than 10 years before a patient begins to experience mild cognitive impairment. Researchers at Brigham and Women’s Hospital studied the association of depressive symptoms in cognitively normal older adults and found that higher levels of amyloid beta may relate to increasing symptoms of anxiety in these individuals. The findings were published in The American Journal of Psychiatry.
“Rather than just looking at depression as a total score, we looked at specific symptoms such as anxiety,” said first author Nancy Donovan, MD, a geriatric psychiatrist at Brigham and Women’s Hospital. “When compared to other symptoms of depression such as sadness or loss of interest, anxiety symptoms increased over time in those with higher amyloid beta levels in the brain.”
Studying the link between depressive symptoms and cognitive impairment is important, as anxiety is common in older people and may indicate a more serious issue. Rising depressive symptoms such as anxiety may be a useful risk marker for seniors, especially those with other genetic, biological, or clinical indicators of high AD risk.
Investigators derived data from the Harvard Aging Brain Study, where 270 community-dwelling, cognitively normal men and women between ages 62 and 90 years old with no psychiatric disorders were examined. The study was aimed at defining neurobiological and clinical changes in early AD. The study participants underwent baseline imaging scans, typically used in studies of AD, and had annual assessments with the 30-item Geriatric Depression Scale (GDS) to detect their depression levels.
The GDS scores were collected and observed over the span of five years, including scores for three clusters of depression symptoms: dysphoria, anxiety, and apathy-anhedonia. The research found that higher brain amyloid beta burden was linked with increasing anxiety symptoms in cognitively normal seniors over time. The findings also suggest that worsening depression symptoms may be an early predictor of AD, supporting their hypothesis that early neuropsychiatric symptoms may be a representation of an early onset of preclinical AD.
“If further research substantiates anxiety as an early indicator, it would be important for not only identifying people early on with the disease, but also, treating it and potentially slowing or preventing the disease process early on,” said Donovan. She also notes that further follow-up is needed to confirm whether escalating depressive symptoms lead to clinical depression and dementia stages of Alzheimer’s over time.