London: A new scientific study from the University of Cambridge suggests that the human brain develops in five clear stages across a person’s lifetime instead of growing steadily and then slowly declining as previously believed. The findings are based on the analysis of almost four thousand brain scans from people ranging from newborn babies to those in their nineties.

Researchers identified four major turning points in brain development around the ages of nine thirty two sixty six and eighty three. These points divide the human lifespan into five phases. According to the study the first stage is childhood from birth to around nine when the brain grows fast but is also reorganising itself. The second stage from nine to thirty two is described as an extended adolescence in which neural networks become more efficient and decision making and emotional control continue developing.

The third phase from thirty two to sixty six is adulthood. During this time scientists say that the brain remains relatively stable with little structural change. The fourth stage from sixty six to eighty three marks the beginning of early ageing where brain connections begin to slowly weaken. The final stage from eighty three onward is late ageing when the brain reorganises again to compensate for the loss of connections possibly relying more heavily on a smaller number of key regions.

Experts say this study could change how health professionals understand learning mental health and cognitive decline. The discoveries may help researchers better identify when the brain is most vulnerable to disorders such as depression dementia and other age related neurological conditions.

Scientists also believe the findings could influence how societies approach education and mental health especially for young adults. Since the brain continues to change until around thirty two the study suggests that support for learning and emotional development may need to continue well beyond teenage years.

Researchers say more studies are now needed to explore how lifestyle environment and experiences may influence the timing and strength of these brain development stages.

The study has been published in the journal Nature Communications.