The assessment and determination of substance addiction problems among young people is important for understanding the factors involved in the problem itself, as well as the administration of appropriate therapy. It is typical for users of addictive substances to have educational problems that are manifested in negative attitudes towards school and teachers, especially in avoiding school and school obligations, that appears as a particularly clear indicator of these problems (Bezinović, 1999). The aim of this study was to investigate the possible differences between male and female adolescents in the frequency of drug use, inclination and recognition of the existence of problems with alcohol and drugs with regard to the class and school they attend. The study was conducted on a sample of 1499 students from different high schools of Zadar County (three-year vocational schools, four-year vocational schools, grammar schools). An anonymous questionnaire was administered, containing questions about gender, age, school and form that student attends. In addition, the following scales were used: Adolescent School Problems (Asch), Alcohol/Drug Proneness Scale (PRO), Alcohol/Drug Problem Acknowledgement Scale (ACK) and Survey on substance use. The results show that adolescents usually consume cigarettes and alcohol, followed by marijuana and seldom by other drugs. A the statistically significant difference between male and female adolescents was defined in the presence of school problems and the existence of problems with alcohol and drugs. The presence of school problems is more expressed in male adolescents, as are problems with alcohol and drugs. A the statistically significant difference was found in the examination of school problems, inclination and existence of problems with alcohol and drugs with respect to the class and school that students attend.

adolescents, Adolescent School Problems (A-sch), Alcohol/Drug Proneness Scale (PRO), Alcohol/Drug Problem Acknowledgement Scale (ACK), Survey on substance use