PLOS Medicine: Brain Age Gap Was Largest in Dementia

Scientists have identified which neurological and psychiatric disorders are associated with the greatest acceleration of brain aging. The largest gap between estimated “brain age” and chronological age was seen in neurodegenerative diseases, particularly Alzheimer’s disease. The study was published in the journal PLOS Medicine.

Researchers in China trained a model to estimate the “biological age” of the brain from MRI scans and then compared nearly 45,900 healthy people with 2,698 patients with various disorders. The measure was the difference between a person’s actual age and the age estimated by the neural network based on the condition of their brain.

The greatest brain aging was observed in people with Alzheimer’s disease and mild cognitive impairment. Markedly accelerated aging was also seen in people with substance use disorders and a number of psychiatric conditions. By contrast, no significant overall differences from the norm were found in people with ADHD or autism spectrum disorders.

Interestingly, different conditions affected different parts of the brain. Psychiatric disorders primarily involved the frontal and temporal lobes, substance use disorders affected networks associated with attention and self-control, while dementia was associated with changes in the frontal and occipital regions of the cortex. This suggests that “accelerated brain aging” is not a single process but rather a collection of different patterns. In the future, this approach could help identify groups at risk earlier and provide more precise assessments of how particular diseases affect the brain, although the findings currently represent statistical patterns rather than a ready-to-use diagnostic tool.

The concept of a brain’s “biological age,” which can differ from its chronological age, has been gaining increasing attention in recent years. Using an MRI scan, a neural network can estimate how “aged” the brain appears. If it looks older than a person’s actual age, this may indicate an underlying risk of disease. The new study suggests that different diseases leave different “signatures” in the brain, potentially helping distinguish them at earlier stages.

Follow NEWS.am Medicine on Facebook and Twitter