Although the concept of child depression is today well admitted, the diagnosis of childhood depression remains difficult due to the variety of its symptoms, many of them being non specific, and the frequency of masked depression. For each period of child development, ie: infancy, early childhood, late childhood and adolescence, depression has particular clinical characteristics which are important to be known for its early recognition. Depression in a child frequently appears to result from the conjunction of a constitutional predisposing ground, one or several losses, and an inappropriate parental response. One must be concerned about the major risk of deleterious effects on psychoaffective, intellectual and somatic development of neglected depression, so that its prevention, early recognition, and treatment are mandatory. According to the cases, treatment requires individual or familial psychotherapy and chemiotherapy, and in particular cases care in a medico-educative establishment.