"Although the brain stops growing in size by early adolescence, the teen years are all about fine-tuning how the brain works. The brain finishes developing and maturing in the mid-to-late 20s. The part of the brain behind the forehead, called the prefrontal cortex, is one of the last parts to mature. "

nimh.nih.gov/…/the-teen-brain-7-things-to-know#:~….