[From early adolescence to adulthood].

In industrialized countries, the transition from early adolescence to adulthood takes a long time (over 10 years) and is a diversified process. Puberty marks the starting point of adolescence, while the end of the adolescent process is defined by social factors, such as integration in the world of work, leaving the parents' home, and living with a stable partner. During adolescence, the difference between boys and girls becomes progressively well established, not only concerning physical growth and body changes, but also concerning lifestyle and health behavior, including risky behavior. On these aspects, the gender gap is more important in France (as in southern European countries) than in most Nordic or Anglo-Saxon countries. Most young people have no major problems, but nearly 10% present emotional and behavioral disorders.