This article shows how the phenomenon of depression may enlighten crucial questions related to the economic dimension of the Freudian psychic apparatus, integrating it to its other dimensions, the topical and the dynamic. Depression is intimately related to the analogous principle that enables and conditions the emergence and preservation of life in biological systems. It seems to follow a parallel negentropic tendency which, in thermodynamics, is in contrast to the natural law of entropy. In other words, depression is the expression of a principle that, according to the biological analogy, governs the construction of psychic life through two groups of processes: differentiation and integration. Clinical vignettes illustrate these principles and processes.
Differentiation; integration; quienscence narcisic; death instinct