Many societies consider delinquency, violence, drug and alcohol abuse, smoking, and early patterns of sexual behaviour that risk sexually transmitted diseases and pregnancy among never married teenagers to be serious problems. These problems can ruin adolescents’ lives by leading them to be put in jail, by limiting their education and vocational training opportunities, by having unwanted children, and by risking the development of serious illnesses. In addition, these problems are costly to a society in economic terms. Crime, drug and alcohol abuse, smoking and high-risk sexual behaviour result in huge health care, judicial and victim-related costs over the life span of an adolescent with serious behaviour problems.
Adolescents who display serious problems in one of these areas frequently develop problems in other areas, too. Many studies from various countries indicate that delinquency, smoking, drug and alcohol use, and sexual behaviour that can cause disease are strongly correlated with each other. All of these problems are also associated with academic failure and school dropout. This makes it particularly important to prevent the development of serious behaviour problems.
