[Clinical expressions of depression]

The main clinical manifestations of depression can be described as a decrease of the psychic tone resulting in a disturbance of mood prone to sadness and a psychomotor retardation with slowness and feeling of fatigue. Anxiety is usually associated to these core symptoms as well as somatic signs. Suicidal risk is always present and is increased during melancolic states. A great clinical polymorphism makes the diagnosis difficult in some cases. If the spontaneous course of depression is usually favorable within a year, antidepressant treatments are necessary to shorten the duration of the illness and to avoid chronicisation and relapse.