The intervention group (group 1) will be exposed to mindfulness in the beginning of the medical course and will be compared to a control group (group 2), not exposed to mindfulness (exposed to theoretical classes) for 3 months. After that, the intervention group (group 1) will receive theoretical classes and the control group (group 2) will be exposed to the mindfulness techniques for 3 months (cross-over). Therefore, both groups (groups 1 and 2) will be exposed to mindfulness in the first year of undergraduation, however in different moments of the course. Then, all first year medical students exposed to mindfulness (groups 1 and 2) will be compared to another class, which didn't have this mindfulness mandatory course in their formation (group 3). They will be compared after 6 months and after one-year of intervention (long-term effect).