The aim of this research is not only to determine the prevalence of depression symptoms among the adolescents but also to present the existence of aggression and criminal behaviors and to identify the operating variables and risk factors. This cross-sectional study was conducted at January-February 2005 in Kayseri. 2217 students selected through simple random sampling from six high schools selected by means of stratified random sampling were included in the sample group. As data-collecting devices, Zung Depression Inventory (ZDI) and a questionnaire developed by the researchers to determine the demographical, socio-cultural characteristics of the students and their behavior disorders were applied. The average of ZDI scores of the students were 49.2±8.6 and it was seen that 9.5% have medium depression, and 1.3% have severe It was seen that ZDI scores of the female students, of those with low incomes, low academic success and whose fathers have low educational levels, and of those who have a hack on, of those having disciplinal problems with their friends outside school and those having disciplinal problems inside their school and of the students who inflict damages to properties are ≥50 (p<0.05). The most important illustrative risk factors of getting ZDI scores ≥50 are gender, the education level of the father, having a hack on, carrying a gun on. As a result of the application of Pearson correlation analyses, a positive correlation between age (r=0.32, p=0.021), male sex (r=0.06, p=0.013) and the number of sisters (r=0.09, p<0.001), and ZDI scores has been found. The scores of depression of the students were found to be low. We thought that gender, educational levels of parents, income level, a case of a fight that has been informed to the police and school administration and the school mates having a hack or gun on could be important factors to decrease the scores of depression.