This paper aims to show how training in psychology leads students (at the beginning and the end of their studies) to consider that psychological disorders result from dispositional factors specific to the patients, particularly in therapeutic failure (fundamental attribution error and hindsight bias). Faced with a clinical case of a somatic disease with psychological repercussions, for which the effect of the initial treatment remains unclear, the students must choose: the repetition of treatment, the recovery or indecision. They must also define the elements that could have contributed to the evolution of the disease using causal attribution scales (C.D.S.II). At least half of the Master's students choose indecision. When they choose to continue the treatment, they more often consider that the patient's condition is partially linked to his dispositions and to determinants controllable by himself. L1's students choose to continue the treatment and are empathetic with the patient. For them, the evolution of his condition is linked to the situation and he cannot control it. In the case of therapeutic failure, training in psychology achieves at best to lead Master's students to choose indecision but it fails partly to lead them to contend with hindsight bias and fundamental error. (Contains 2 tables, 2 figures, and 6 notes.)