[Depression and psoriasis].

Psychiatric co-morbidity is very frequently associated with psoriasis and depression is observed in numerous patients with psoriasis. Early detection and treatment are very important. The links between psoriasis and depression are not only psychopathological. Biological factors could also explain this association. There is a vicious circle psoriasis-alteration of quality of life-depression, but psoriasis improvement is not always followed by an improvement of depression. A contrario, it is obvious that a depressive patient has a bad observance of treatment.