There are lots of changes going on in a teen\u2019s brain during adolescence. Here are some things you should know. The teen brain reaches its maximum physical size around age 11 for girls and 14 for boys. While it doesn\u2019t increase in size after that, it does continue developing and maturing until the mid to late 20s. The prefrontal cortex, the region responsible for planning, prioritizing and controlling impulses, is one of the last brain regions to mature. The adolescent brain is well prepared to adapt to new technology in our fast-paced digital world. \u00a0Mental disorders, such as anxiety, depression, schizophrenia, bipolar disorder, and eating disorders, can emerge during these years, although some of the changes teen brains are going through may actually help protect against long-term mental disorders. While adolescence is a vulnerable time for teen brains, the vast majority of young people go on to become healthy adults. And what most parents already realize, teens\u2019 brains require more sleep than those of children and adults. In fact, experts say, teens should get at least nine hours of sleep a night to be engaged and productive during the day, but most don\u2019t. The lack of sleep has increased markedly since 2009, when use of smartphones became more widespread. Studies indicate that the light from smartphones and tablets disrupts a teen\u2019s natural sleep-wake cycle. It\u2019s particularly important to curb use of screen devices right before bed to insure a longer and better quality sleep and a sharper brain the next day.