The brain creates every feeling, emotion and desire we experience, and stores every one of our memories. And yet, until very recently, scientists believed our brains were fully developed in childhood. Now, thanks to imaging technology that enables us to look inside the living human brain at all ages, we know that this isn't so - that the brain goes on developing and changing right through adolescence into adulthood. So what makes the adolescent brain different? What drives the excessive risk-taking or the need for intense friendships common to this age group? Why does an easy child become a challenging teenager? And why is it that many mental illnesses - depression, addiction, schizophrenia - begin during these formative years. Drawing upon her cutting-edge research in her London laboratory, award-winning neuroscientist, Sarah-Jayne Blakemore explains what happens inside the adolescent brain, and what her team's experiments have revealed about our behaviour, and how we relate to each other and our environment as we ?go through this period of our lives. She shows that while adolescence is a period of vulnerability, it is also a time of enormous creativity - one that should be acknowledged, nurtured and celebrated. Our adolescence provides a lens through which we can see ourselves anew. It is fundamental to how we invent ourselves.