High Amyloid, Anxiety, Depression May Predict Early Alzheimer's

A new study published in the American Journal of Psychiatry suggests elevated levels of amyloid beta combined with symptoms of anxiety and depression that escalate over time may indicate preclinical Alzheimer's disease, reports Medscape . "Alzheimer's disease begins with a long 'preclinical' phase defined by the accumulation of brain deposits of fibrillar amyloid and pathological tau," the researchers note. They also say preclinical observations found cognitively normal older persons with biomarker indications of amyloidosis are more likely to experience increasing depression symptoms over time. "These preliminary observations raise more pointed questions as to the quality, severity, and time course of depressive symptoms that are most characteristic of preclinical Alzheimer's disease and the specificity of their associations with Alzheimer's molecular markers," the investigators point out. The team examined the relationship between cortical aggregate amyloid beta and longitudinal measures of depression in a cohort of cognitively normal older adults whose levels of amyloid beta showed wide variance. They focused on 70 cognitively normal community-dwelling men and women without major psychiatric disorders at the time of participation. The team found a significant difference in mean Pittsburgh compound B binding between participants who lacked a history of depression, compared to those with current depression, but not compared to those with past depression.