Somatic illnesses, especially neurological ones, increase the risk of psychiatric complications. These are most often anxiety-depressive complications, which are not always diagnosed. This lack of recognition is due, among other things, to the fact that the practitioner may consider depression as a "normal" reaction to the neurological disease. Diagnostic erraticism is all the more important because the "symptomatic overlap" between neurological pathologies and depression is common. Anorexia, weight loss, insomnia, etc. can be observed in neurological disorders as well as in most depressive states. However, the diagnosis of depression and its treatment allow the improvement of the patient's quality of life, decrease the suicidal act and could even influence the prognosis of the neurological pathology.