Risk and reward

Several lines of evidence suggest that the brain circuitry involved in emotional responses is changing during the teen years.

Functional brain imaging studies, for example, suggest that the responses of teens to emotionally loaded images and situations are heightened, relative to younger children and adults. The brain changes underlying these patterns involve signaling molecules that are part of the reward system with which the brain motivates behaviour.

These changes shape how much different parts of the brain are activated in response to experience and in terms of behaviour, the urgency and intensity of emotional reactions.

An understanding of how the brain of an adolescent is changing may help explain a puzzling contradiction of adolescence. Young people at this age are close to a peak of physical health, strength, and mental capacity and yet for some, there are many hazards. Rates of death between ages 15 to 19 are about 6 times that of the rate between ages of 10 to 14. Crime rates are highest among young males and rates of alcohol abuse are high relative to other ages.

Even though most adolescents come through this transitional age well, it’s important to understand the risk factors for behaviour that can have serious consequences. Genes, childhood experience, and the environment in which a young person reaches adolescence all shape behaviour. Adding to this complex picture, research is revealing how all these factors act in the context of a brain that is changing, with its own impact on behaviour.