Grant: Operating Grant

Substance use seems to wax in adolescence and wane in early adulthood. Yet adolescents know as well as adults about the hazards of substance use but do not seem to make good use of this information. The frontal lobes, which are important in decision making, develop steadily throughout adolescence. However, puberty begins slowly in late childhood, accelerates in mid adolescence and slows down by late adolescence. Researchers have noticed that the rate at which pubertal maturation proceeds initially exceeds that of the frontal lobes. They think that this may create a maturational gap that would drive adolescent substance use; it is only by late adolescence and young adulthood, when pubertal maturation slows down and when the brain has matured sufficiently to handle the motivational changes brought up by puberty, that the gap begins to close. However, not all children experience puberty in the same manner. And it may be those for whom the gap between pubertal and brain maturation is greatest who are most at risk for smoking, drinking, and taking drugs, particularly if they spend time with deviant peers, lack positive relations with adults, and already have a history of behaviour problems since childhood. This research project will follow several hundreds of adolescents yearly from the ages of 13-17 years to examine behaviour, pubertal changes, and decision-making. These children have been followed yearly since birth and our previous documentation of their developmental history including behaviour, early puberty, social environment, and decision making will prove extremely valuable. Identifying mechanisms at play in childhood and adolescence will further help current prevention initiatives, which rely mainly on universal approaches, to become more targeted.