A new longitudinal study of more than 500 adolescents led by researchers at King’s College London shows that changes in DNA methylation across the teenage years are linked to brain development and to rising depressive symptoms, cannabis use and binge drinking, pointing to a potential biological pathway connecting experience, brain maturation and mental health.
Summary
Adolescence is a crucial period for brain development, but we still know relatively little about how biological changes in the body relate to mental health during these years. In this study published in Molecular Psychiatry, researchers analysed blood samples and brain MRI scans from 506 young people at ages 14 and 19, examining more than 372,000 DNA methylation sites across the genome. They identified 18 groups of DNA changes that shifted together over time, including 10 linked to genes involved in brain development and signalling. The study found that these molecular changes were tied to coordinated changes in brain regions involved in emotion, motivation and reward. Young people with greater increases in depressive symptoms, cannabis use and binge drinking also showed greater DNA methylation changes and greater cortical thinning in this brain network. The findings suggest that DNA methylation may help explain how adolescent experiences and behaviours become biologically embedded and linked to brain development and mental health risk.
Three key take-home messages
- The teenage years leave a measurable biological signature.
The study mapped coordinated DNA methylation changes across adolescence and showed that these patterns are stable, biologically meaningful, and reproducible across datasets. - These DNA changes are linked to how the brain matures.
Changes in DNA methylation tracked with structural changes in brain systems involved in cognitive control, emotion and reward, especially along fronto-limbic-striatal pathways. - DNA methylation may be one pathway linking experience to mental health risk.
Increases in depressive symptoms, cannabis use and binge drinking were associated with stronger DNA methylation changes and greater cortical thinning, with mediation analyses suggesting DNA methylation may help bridge behaviour and brain change.
A quote from the senior author:
“Adolescence is a critical window for brain development, and our findings show that DNA methylation changes are linked to brain maturation and emerging mental health symptoms over time. To really understand how environmental and developmental influences shape mental health, we now need more longitudinal studies that track molecular and brain changes together across development. This will be essential for identifying earlier markers of vulnerability and new opportunities for prevention.”
