A groundbreaking study has revealed that the human brain develops in five distinct phases, with a surprisingly long adolescence that lasts until around age 32. The research, published in Nature Communications, identifies four pivotal turning points in brain structure at ages nine, 32, 66, and 83.
By analyzing brain scans from 4,000 people, researchers at the University of Cambridge mapped how the connections between brain cells change over a lifetime. They found these changes are not smooth but occur in clear, distinct phases:
- Childhood (Birth-9):Â A period of rapid growth and “pruning” of neural connections.
- Adolescence (9-32):Â A “huge shift” towards ruthless efficiency, making the brain’s network more streamlined. This phase is now shown to last into the early 30s, aligning with when many cognitive functions peak.
- Adulthood (32-66):Â A long period of relative stability, though brain efficiency begins a very slow decline.
- Early & Late Ageing (66+):Â The brain’s organization shifts, with different regions becoming less coordinated with each other.
The researchers state these findings help explain why the risk for mental health disorders is highest during adolescence and why conditions like dementia emerge in later life stages. “The brain rewires across the lifespan,” said lead researcher Dr. Alexa Mousley. “It’s not one steady pattern—there are fluctuations and phases.”
By James Kisoo
