This study evaluates a newly developed information booklet about depression among adolescents. The aim was to examine the enhancement of knowledge through the booklet with the objective of reducing stigma and facilitating awareness of own treatment needs. 628 German ninth graders were enrolled in a pre–post-follow-up study using study-specific questionnaires to investigate knowledge enhancement in seven depression-related topics. Exploratively, knowledge enhancement was calculated with respect to education level and gender. Additionally, the students assessed the booklet’s layout, content and utility. Knowledge enhancement was analyzed using repeated measures ANOVA for index values of the booklet’s topics. The effect size partial eta square (η²) was computed. The pre–post-follow-up comparison yielded significant knowledge enhancement for all seven index values (p