Nikhil Prasad Fact checked by:Thailand Medical News Team Jul 29, 2026 42 minutes ago
Medical News: Scientists have uncovered compelling evidence that different brain disorders accelerate brain aging in remarkably different ways, with Alzheimer's disease showing the most dramatic effects, followed by addiction-related conditions and psychiatric illnesses. The findings suggest that a simple MRI-based measure of "brain age" could one day help doctors identify disease progression, assess risk, and guide treatment decisions with greater precision.
Large MRI analysis reveals that dementia, addiction, and psychiatric disorders each accelerate brain aging through distinct neural pathways while sharing changes in the prefrontal cortex.
Researchers found that while many neurological and psychiatric disorders make the brain appear older than a person's actual age, each disorder leaves behind its own unique fingerprint within specific brain networks. Interestingly, common developmental disorders such as attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) did not show evidence of accelerated brain aging.
The study was conducted by researchers from the Nanjing University of Aeronautics and Astronautics, China, together with collaborators using several large international neuroimaging datasets.
Measuring How Old the Brain Really Is
The researchers used a measure known as Predicted Age Difference (PAD). PAD compares a person's chronological age with the age predicted from structural MRI brain scans using advanced machine learning models.
A positive PAD means the brain appears biologically older than expected, while a negative value indicates a younger-looking brain.
To generate one of the largest analyses ever performed, the research team analyzed structural MRI scans from 45,900 healthy individuals and compared them with scans from 2,698 patients diagnosed with nine common brain disorders, including:
-Alzheimer's disease (AD)
-Mild cognitive impairment (MCI)
-Schizophrenia
-Bipolar disorder
-Major depressive disorder
-Alcohol use disorder
-Tobacco use disorder
-ADHD
-Autism spectrum disorder
Rather than simply calculating overall brain age, the scientists also examined which brain regions contributed most to the accelerated aging patterns and linked those changes to underlying gene activity.
Dementia Shows the Greatest Brain Aging
The strongest evidence of accelerated brain aging was found in Alzheimer's disease.
Patients with Alzheimer's had the largest increase in PAD, followed by those with mild cognitive impairment, a condition that often precedes Alzheimer's disease.
The next highest levels were observed among individuals with alcohol and tobacco addiction. Patients suffering from both addictions simultaneously showed especially pronounced brain aging.
Psychiatric disorders including schizophrenia, bipolar disorder, and major depressive disorder also demonstrated significant increases in biol
ogical brain age, although the effects were generally smaller than those seen in dementia and addiction.
Surprisingly, ADHD and autism showed almost no measurable difference from healthy individuals, suggesting that these developmental disorders involve brain changes that differ fundamentally from the aging processes seen in adult neurological diseases.
Each Disorder Targets Different Brain Networks
One of the most important discoveries was that accelerated brain aging does not occur uniformly throughout the brain. Instead, every disorder affected distinct neural circuits.
Psychiatric illnesses primarily involved the frontotemporal network, regions critical for reasoning, decision-making, emotional regulation, and social behavior.
Addiction produced aging signatures within the default mode network, salience network, putamen, and thalamus, areas involved in reward processing, motivation, attention, and habit formation.
Dementia mainly affected the fronto-occipital network, including regions essential for memory, visual processing, and higher cognitive function.
Despite these differences, one structure consistently appeared across nearly every disorder—the prefrontal cortex. This suggests that this brain region may represent a common pathway through which multiple diseases accelerate biological brain aging.
Genes Reveal Different Biological Mechanisms
This
Medical News report also highlights another major strength of the study: the integration of brain imaging with gene expression data.
The researchers identified biological pathways linked to the abnormal brain aging patterns seen in each disease category.
Psychiatric disorders were associated with genes involved in protein translation and cellular transport, processes essential for maintaining healthy neurons.
Addiction-related brain changes were linked to genes involved in energy metabolism, transmembrane transport, and synaptic signaling, reflecting how alcohol and tobacco disrupt communication between brain cells and alter dopamine and glutamate pathways that reinforce dependence.
For dementia, accelerated brain aging corresponded with genes regulating protein localization, DNA metabolism, and DNA damage repair. These findings align with longstanding evidence that accumulated DNA damage and impaired cellular repair contribute to neurodegeneration and cognitive decline.
Robust Findings Across Large Populations
A major strength of the investigation lies in its scale and consistency. The researchers confirmed their findings using multiple independent imaging datasets, different brain atlas resolutions, and several machine learning prediction models. This high level of replication increases confidence that the observed brain aging patterns reflect genuine biological processes rather than technical artifacts.
The study also found that higher PAD correlated with worsening symptoms in dementia, particularly Alzheimer's disease and mild cognitive impairment. However, similar symptom relationships were not observed in addiction or psychiatric disorders, suggesting that accelerated brain aging may play different roles depending on the disease.
The researchers noted one important limitation. Psychiatric disorders and addiction frequently occur together, and these overlapping conditions were not fully accounted for, meaning some of the observed effects may partly reflect shared disease mechanisms.
Conclusion
The findings provide strong evidence that accelerated brain aging is a common biological feature across many major brain disorders, but that each disease follows its own unique anatomical and molecular pathway. While dementia produced the greatest increase in biological brain age, addiction and psychiatric illnesses also showed significant changes, whereas ADHD and autism did not. The consistent involvement of the prefrontal cortex suggests it may serve as a central hub connecting aging with multiple neurological diseases. Future research could transform these MRI-derived brain aging signatures into practical biomarkers that help physicians detect disease earlier, predict progression, distinguish similar disorders, and personalize treatment decisions long before irreversible brain damage occurs.
The study findings were published in the peer reviewed journal: PLOS Medicine.
https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1004860
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