Asper the new study, an association between elevated amyloid beta levels and the worsening of anxiety symptoms. The discoveries support the hypothesis that neuropsychiatric symptoms could represent the early manifestation of Alzheimer’s disease in older adults.
Previous studies have recommended depression and other neuropsychiatric symptoms might be predictors of AD’s progression during its “preclinical” phase, during which time brain deposits of fibrillar amyloid and pathological tau accumulate in a patient’s brain.
This phase can occur over 10 years before a patient’s onset of mild cognitive impairment. Investigators at Brigham and Women’s Hospital examined the association of brain amyloid beta and longitudinal measures of depression and depressive symptoms in psychologically normal, older adults.
Their discoveries, published by The American Journal of Psychiatry, recommend that higher levels of amyloid beta might be related to increasing symptoms of anxiety in these people. These outcomes support the theory that neuropsychiatric symptoms could be an early indicator of the AD.
First author Nancy Donovan, MD, a geriatric psychiatrist at Brigham and Women’s Hospital said, “rather than just looking at depression as a total score, we looked at specific symptoms such as anxiety. At the point when compared with different symptoms of depression such as loss of interest, anxiety symptoms increased after some time in those with higher amyloid beta levels in the brain“.
“This recommends anxiety symptoms could be a manifestation of Alzheimer’s disease prior to the onset of cognitive impairment. If further research shows substantiate anxiety as an early indicator, it would be important for not only distinguishing individuals early on with the disease but in addition, treating it and possibly slowing or preventing the disease process early on.”
As anxiety is common in older individuals, rising anxiety symptoms may prove to be most helpful as a risk marker in older adults with other genetic, biological or clinical markers of high AD chance. Scientists derived information from the Harvard Aging Brain Study, an observational study of older adult volunteers aimed at defining neurobiological and clinical changes in early Alzheimer’s disease.
The members included 270 group dwelling, cognitively normal men and women, between 62 and 90 years of age, with no active psychiatric disorders. People also underwent baseline imaging scans commonly used as a part of studies of Alzheimer’s disease, and yearly assessments with the 30- item Geriatric Depression Scale (GDS), an assessment used to detect depression in older adults.
The team estimated total GDS scores and also scores for three clusters symptoms of depression-apathy-anhedonia, dysphoria, and anxiety.
These scores were looked at over a span of five years. From their study, the group found that higher brain amyloid-beta burden was related to increased anxiety symptoms after some time in cognitively normal older adults.
The outcomes recommend that worsening anxious-depressive symptoms might be an early predictor of elevated amyloid beta levels – and, thus AD – and provide help for the hypothesis that emerging neuropsychiatric symptoms represent to an early sign of preclinical Alzheimer’s disease.
Further longitudinal follow-up is needed to determine if these escalating depressive symptoms give rise to clinical depression and dementia stages of Alzheimer’s disease over time, Donovan notes.