Is Tau Protein Linked to Depression and Brain Aging in Older Adults?

Rising levels of a brain protein called tau may be linked to increasing depressive symptoms in older adults.

Could depression be an early warning sign of Alzheimer’s disease? New research suggests that changes in a brain protein called tau may hold part of the answer.

Could Tau Protein Hold the Key to Depression in Aging?

As people age, higher levels of a protein called tau are linked to more symptoms of depression. In a new study published in JNeurosci, Teodora Markova from Brandeis University and her team looked at how tau levels relate to depression in older adults, both with and without the memory and thinking problems associated with Alzheimer’s disease (1^✔ ✔Trusted Source
Tracking the Continuous Time Dynamics of Tau and Depressive Symptoms Across the Alzheimer’s Disease Continuum

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Tau Protein may Signal Depression Before Cognitive Decline

The researchers assessed data collected by the Alzheimer’s Disease Neuroimaging Initiative from elderly men and women with and without cognitive issues. Participants had completed several tau-detecting imaging scans and questionnaires measuring depressive symptoms across multiple visits.

Over time, the speed of tau buildup in participants regulated how quickly depressive symptoms rose in individuals with cognitive skills intact. Furthermore, in cognitively intact people, increased tau levels could predict higher scores in the depression test. These findings suggested to the researchers that tau accumulation precedes and likely contributes to more depressive symptoms. Notably, none of these observations were found in individuals with Alzheimer’s or even mild cognitive impairment.

Could Rising Tau Explain Changing Mood with Age?

According to the research team, this work shows that early increases in tau levels during aging may contribute to the rise of depressive symptoms. The researchers suggest that monitoring depressive trajectories in aging populations could complement other measures to help assess risk for neurodegenerative disease.

“Future work can continue to track how participants’ tau levels and depression symptoms evolve over longer periods of time, particularly as some develop cognitive impairment or more clinically significant levels of depression. Continuing to follow these trajectories, observing how early mood changes relate to later clinical outcomes, and establishing relationships with other methods tracking the development of Alzheimer’s disease will provide more clarity on methods to determine which individuals may be at an increased risk,” says Markova.

Reference:

1. Tracking the Continuous Time Dynamics of Tau and Depressive Symptoms Across the Alzheimer’s Disease Continuum – (https://www.jneurosci.org/content/early/2026/08/17/JNEUROSCI.2309-25.2026)

Source-Eurekalert