Dignity Therapy (DT) is a multi-dimensional, brief and individual psychotherapeutic intervention, designed to increase the sense of dignity in patients. The aim of our study was to evaluate the effectiveness of Dignity Therapy in a group of patients suffering from major depressive disorder or bipolar disorder. The results of the study in a small group of patients showed the effectiveness of DT. The PDI (Patient Dignity Inventory Scores) showed a statistically significant difference in the whole group of patients with a reduction in the mean overall score (T0 vs T1 = Mean Difference: 13.700, T-Score: 4.834, Eta squared: 0.709, p: 0.001, statistically significant). However, there is a need to deepen the study to try to offer an opportunity for treatment in this group of patients.