when does your brain fully develop

The brain is typically considered fully developed around the age of 25. This is primarily when the prefrontal cortex, the part responsible for higher-level functions such as emotional regulation, decision-making, impulse control, and long-term planning, finishes maturing. Although the brain reaches about 90% of its adult size by age 5, the complex wiring, especially in the prefrontal cortex, continues developing through adolescence into early adulthood. Adolescence is marked by intense brain reorganization, with the limbic system (emotion and reward center) developing earlier than the prefrontal cortex, which leads to the typical teenage behaviors like impulsivity and emotional outbursts. Full maturity, including adult-level thinking and emotional regulation, is achieved around the mid-20s. Even after this point, the brain remains plastic, meaning it can continue to form new connections and adapt through experiences and learning throughout life, but the foundational structural development is largely complete by about 25 years old.