MRI study links brain disorders to distinct patterns of older-appearing brain structure

An observational study published in PLOS Medicine examined whether brain disorders are associated with differences between MRI-predicted brain age and chronological age. Researchers led by Shile Qi at Nanjing University of Aeronautics and Astronautics analyzed structural MRI data from 45,900 controls across several imaging databases and 2,698 people with neurological, psychiatric or addiction-related conditions. The principal measure was predictive age difference (PAD), with positive values indicating an older-appearing brain.

Alzheimer’s disease and mild cognitive impairment had the strongest associations with higher PAD. Psychiatric disorders and addiction were also associated with increased PAD, whereas ADHD and autism spectrum disorder showed no significant overall differences from controls. The source did not provide effect sizes or confidence intervals.

Regional patterns differed: psychiatric disorders were associated with elevated PAD in frontal and temporal lobes, while dementia was linked to higher PAD in frontal and occipital cortex. Addiction-related differences involved the default mode and salience networks, putamen and thalamus. Gene-expression analyses also identified condition-associated differences that may point to distinct biological pathways.

These imaging associations do not establish that the conditions cause faster brain aging or demonstrate clinical utility for PAD as a biomarker. Co-occurring psychiatric disorders and addiction complicate attribution of individual effects. Chinese public research grants supported the study; the funders reportedly had no role in its conduct or publication.