By comparing the brain's response to a food reward in adult and teen rats, researchers have pinpointed some differences that might explain why adolescents take more risks and are more prone to addiction, depression and schizophrenia.

"The brain region that is very critical in planning your actions and in habit formation is directly tapped by reward in adolescents, which means the reward could have a stronger influence in their decision-making, in what they do next, as well as forming habits in adolescents," study researcher Bita Moghaddam, of the University of Pittsburgh, told LiveScience. "Teenagers could do stupid things in response to a situation not because they are stupid, but because their brains are working differently. Somehow they perceive and react to a situation differently."