PET imaging links psychosis to Alzheimer's-related brain findings
New imaging research suggests that many adults who develop psychosis-related hallucinations or delusions later in life show brain changes associated with Alzheimer's disease and other neurodegenerative disorders.
Using PET imaging, researchers found that about 65% of patients whose psychosis symptoms first appeared after age 40 had abnormal tau protein accumulation, compared with about 15% of healthy older adults. A separate analysis also revealed amyloid positivity in 35% of patients versus 2% of controls. The new data represent some of the first in vivo evidence to link late-onset psychosis to neurodegenerative pathology.
Experts hope that the new study could reshape how late-onset psychosis is evaluated.
“Patients can show the same symptoms, such as hallucinations or delusions, but their clinical course and response to treatment can be very different,” corresponding author Manabu Kubota, with the Advanced Neuroimaging Center, Institute for Quantum Medical Science in Japan, and colleagues noted. “This study started from a clinical question: whether hidden biological differences in the brain could explain those differences.”
The study included 37 patients with psychosis beginning after age 40 and 47 healthy older adults. Investigators used amyloid PET imaging along with the tau PET tracer florzolotau (18F) to identify protein deposits associated with Alzheimer's disease and other tau-related disorders and compare findings between both groups.
This revealed multiple disease patterns. Some patients showed both amyloid and tau accumulation consistent with Alzheimer's, while others demonstrated tau deposits without amyloid, suggesting non-Alzheimer's neurodegenerative processes. In amyloid-negative patients, tau accumulation was most prominent in the parietal and occipital lobes, with greater build-up in the parietal lobe correlating with decreased executive function among amyloid-positive patients.
The team suggested their findings highlight molecular imaging's potential for providing a more objective approach to evaluating patients with late-onset psychosis. Researchers believe PET imaging may eventually help distinguish Alzheimer's-related psychosis from other neurodegenerative causes, supporting earlier diagnosis and more personalized treatment strategies.
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In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.