Brown University Study Reveals Distinct Neuropsychiatric Markers for Diagnosing Combined Alzheimer’s and FTLD in Living Patients

Brown University researchers identify specific behavioral markers, like personality changes, that help diagnose combined Alzheimer's and FTLD in living patients.

By: AXL Media

Published: Mar 17, 2026, 5:28 AM EDT

Source: Information for this report was sourced from Brown University

The Diagnostic Challenge of Overlapping Neurodegenerative Pathologies

While Alzheimer’s disease is frequently studied as an isolated condition, it rarely occurs in a vacuum within the aging human brain. New research from Brown University’s Warren Alpert Medical School has shed light on the frequent co-occurrence of Alzheimer’s and frontotemporal lobar degeneration, a less understood disorder that has historically only been confirmable via autopsy. By analyzing the neuropsychiatric profiles of nearly 1,000 patients, researchers have demonstrated that specific behavioral changes can serve as clinical "red flags" for the presence of multiple pathologies. According to lead author Daliah Ross, identifying these combined cases is essential because patients with dual diagnoses often experience a significantly more aggressive and complex progression of symptoms than those with a single disorder.

Distinctive Behavioral Profiles as Diagnostic Indicators

To isolate the symptoms unique to combined pathology, the research team examined data from 29 NIH funded Alzheimer Disease Research Centers. They focused on 919 individuals whose postmortem examinations confirmed varying levels of both Alzheimer’s and FTLD. The analysis revealed that when compared to patients with FTLD alone, those with both conditions were far more likely to exhibit anxiety, delusions, and irritability. However, when compared to the Alzheimer’s only group, the dual pathology patients showed a much higher incidence of personality changes and disinhibition. These findings suggest that the presence of FTLD in an Alzheimer’s patient manifests as a distinct behavioral signature that clinicians can use to provide a more accurate living diagnosis.

The Clinical Impact of Personality Change and Disinhibition

One of the most profound aspects of FTLD is its impact on a patient’s social conduct and core personality, traits that are not typically the primary focus of early stage Alzheimer’s care. According to Dr. Edward Huey, director of the Memory and Aging Program at Butler Hospital, there is a direct and strong association between the volume of FTLD neuropathology and symptoms like apathy and inappropriate social behaviors. Because these symptoms are highly impactful on the quality of life for both patients and their families, a clearer diagnostic path is vital. Knowing that a patient’s personality shift i...