Previous studies have shown that the transition from elementary to secondary school is an event that causes a significant increase in cortisol (stress hormone) in adolescents. The DéStresse et Progresse program is aimed at preventing stress and its related problems, which came out of work done in recent years in the field of the biology of stress. This program was tested and validated with adolescents in the first year of high school, and showed significant effects on the level of cortisol and the level of depressive symptoms in young people most at risk. The objective of this study is to assess the effects of the program on a small group of subjects in their last year of elementary school, but in a special structure, since the group is already integrated into a secondary school. Forty-nine subjects, divided into two classes, participated in a study based on a pretest/ post-test estimate with repeated measurements. Contrary to what was expected, the results show a significant average increase of salivary cortisol over the course of our study, which could be attributed to the early transition resulting from the integration of our sample into the high school. However, an increase in cognitive performance, self-esteem and a reduction in depressive symptoms for all students were observed as a result of the program.