This research aims to assess the effectiveness in both the short and long term of a brief and group Cognitive-Behavioral Therapy (CBT) in a university setting and evaluate if there are changes in the cognitive styles of the participants. Three groups of university students were made: a TCC group (Cognitive behavioral treatment of students with depressive symptoms), a control group (non-treated controls students with depressive symptoms) and a healthy group (non-treated students without depressive symptoms). The results showed a significant improvement in depressive symptoms in both the short and long term, and changes in the cognitive style of the treated group, especially in the long term rather than the short. However, the results of the healthy group suggest that the improvement of the CBT group is not enough to make the subjects show complete well-being. Therefore, the efficacy of CBT for depression seems confirmed once again, as well as the predictions of the cognitive models for the comprehension, treatment, and prevention of depression among university students.