The speed at which a child’s brain matures can forecast whether they will develop depression or anxiety as a teenager up to four years before symptoms emerge, according to research published in Nature. Analysing nearly 30,000 brain scans, scientists at the University of Iowa and Mass General Brigham found that children with a thicker cortex in sensory regions at age nine were significantly more likely to experience anxiety and depression by age 13.
During childhood and adolescence, the brain’s outer layer, the cerebral cortex, naturally thins as unused neural connections are pruned to make brain function more efficient. Tracking children every two years from age nine, researchers observed that this thinning follows a distinct wave: primary sensory regions like the visual cortex begin to mature at around age 13, followed by frontal areas governing focus, planning and emotional regulation at around 16.
When the team linked these brain scans to mental health surveys, a clear predictive pattern emerged. Children with a thicker cortex in sensory regions at age nine were more likely to report anxiety and depression by age 13. By cross-referencing scans with brain atlases, the researchers discovered that regions where cortical thickness predicted future symptoms overlapped with gene networks active in the womb, suggesting that early genetic programming lays the groundwork for adolescent mental health risks.
“The question is not 'what does this region do?' It's 'when does this region mature?'” said study co-author Dr Joshua Roffman, a psychiatrist at Mass General Brigham.
The findings challenge long-standing assumptions about how psychiatric disorders develop. Dr Avram Holmes, a systems neuroscientist at Rutgers University, said the work “provides one of the clearest pictures yet of how the cortex develops from childhood into adolescence” but stressed it is not yet “sufficient in its own right to predict illness outcomes” for an individual child. Experts suggest that a thicker cortex late in childhood may reflect delayed brain plasticity, making it harder for children to adapt to their environments. Because the study relies on population-level trends, the scientists emphasise the patterns cannot yet be used to diagnose individual children in clinics.
Analysis
Why This Matters
- Could enable earlier identification of children at risk for depression and anxiety, potentially allowing preventive interventions years before symptoms appear.
- Shifts the understanding of mental health disorders from being solely about brain regions to also considering the timing of brain development.
- Opens the possibility of using brain imaging as a screening tool, though clinical applications remain years away.
Background
The cerebral cortex naturally thins during childhood and adolescence as the brain prunes unused neural connections, a process that makes brain function more efficient. This study tracked children every two years from age nine, linking their brain scan data to mental health surveys. By analysing nearly 30,000 scans over six years, the researchers identified a predictive pattern: a thicker cortex in sensory regions at age nine was associated with anxiety and depression at age 13. Overlaps with gene networks active in the womb suggest the vulnerability may be set in motion before birth.
Key Perspectives
Researchers (study authors): They argue the key question is not which brain region is involved but when it matures. The findings point to a disrupted developmental timeline as a root cause of later mental health conditions, and they highlight the role of early genetic programming.
Clinicians and mental health experts: While noting the study provides the clearest picture yet of cortical development, they caution that the population-level trends are not precise enough to diagnose individual children. The work is an important step but not yet ready for clinical use.
Critics/Skeptics: No opposing views are presented in the source material. The main limitation acknowledged by the researchers themselves is that the patterns cannot predict outcomes for a specific child, only for groups.
What to Watch
- Future studies testing whether the same predictive patterns hold in more diverse populations and younger age groups.
- Development of algorithms that could combine brain scans with other risk factors to improve individual-level prediction.
- Potential integration of cortical thickness measurements into routine paediatric mental health screening, though this is likely several years away.
