Abstract : Depression is a major public health problem. According to the World Health Organization (OMS), depression is currently the second cause of disability in developing countries. Depression is also one of the most frequent mental illnesses. When treating depression, the main objective is to achieve complete remission and to prevent recurrence. Unfortunately, in clinical practice, this aim is particularly difficult to reach. Indeed, in clinical trials and in naturalistic studies, remission levels are rather low. The challenge is to individualize the treatment of depression taking account clinical specificities, but also advances in the field of biological and genetic research. Today, intense psychiatric research tries to discover biomarkers to predict treatment response. Because individuals are highly different from a biological, psychological and sociological point of view, more personalized therapeutic approaches are recommended.