The present study analyzes the prevalence of depressive symptomatology in a sample of adolescent school students and how it is related to other factors in the school and clinical environments, with the ultimate aim of obtaining a predictive model for depressive symptomatology in the school environment. The sample was made up of 1285 students aged 12 to 16. Participants filled out the Children’s Depression Scale (CDS) and the Behavior Assessment System for Children (BASC S3), while their class teachers provided information on the academic performance of each student. The study found a prevalence of 3.8% of participants with severe depressive symptomatology, with significantly higher scores in girls, though there were no differences by age. The most prominent predictors in both sexes were: social stress, atypicality, anxiety, feelings of incompetence and somatization. For boys, external locus of control was also a predictor, and in the case of girls, self-esteem. We discuss the implications of these findings and proposals for future research.