Presents a review of the depressive syndromes and an analysis of depressive phenomenology from an existential point of view. Depression is seen as (a) a frozen or overdetermined future; (b) the disruption of normal rhythmical experiencing (the basic law of human interaction); and (c) a hyperstructuring which prevents normal, spontaneous, free interaction. An existential approach to understanding differing modalities of treatment is also presented. A general 3-phased program is proposed, in which the degree of illness or inhibition determines the use of structured, facilitative, or "laisser devenir" (allow to become) therapy. These and other concepts are discussed and developed at length. (56 ref.)