One of the earliest papers written by Sigmund Freud was his 1915 model of mourning under a psychoanalytic perspective, "Mourning and Melancholia". The book is based on metapsychological early theories that help explain the process of understanding, processing, and then accepting death.
In Freud's psychoanalytical definition, decathexis is an "incremental divestment of libido" from an object of affection. In other words, is the systematic detachment from emotional and affective binds that unite us to something or someone, particularly, when the possibility of losing such thing or someone is high. According to Freud, this process is systematic because it takes a lot of psychical and physical energy; it is basically going against the grain and, in reality, there is never full detachment from an object of affection. Precisely, the fact that there IS a lot of connection what propels the need to decathect; the more energy is invested in the process, the more pain is tried to be mitigated.
In Freud's own words
The tasks is carried bit by bit, under great expense of time and cathectic energy, while all the time the existence of the object is continued in the mind. Each single one of the memories and hopes which bound the libido to the object is brought up and hyper-cathected, and the detachment of the libido from it is accomplished...
The ultimate goal of mourning is to repair the psyche, restore psychological balance, and feel the freedom to engage in another experience involving love, even with the fear of loss. The process of mourning has to take place in its entirety for it to release the individual from co-morbidities such as guilt, aloofness, or even anger. Hence, although decathexis is part of the natural needs of our ego to defend itself from psychological pain, it is best to allow ourselves to engage in the entire mourning process, painful as it is, so that the entire process begins and ends in a healthy way.
When the work of morning is completed, the ego becomes free and uninhibited again (Freud, 1917)
In another Freudian point of view, Moore and Fine (1991, 122) convey that decathexis is the second part of the mourning process. The first step, being the actual understanding of the loss, is followed by decathexis, which is the withdrawal of energy and attachment toward the object of affection. The third step would then be REcathexis, which is the resuming of normal dynamics in everyday life once mourning has been carried on successfully.
Decathexis is a broad Freudian concept that is seen to be a central psychic function [psychic: of psychological function; Psychology: pertaining to or noting mental phenomena (Random House Dictionary)] that is present in repression, narcissism and mourning. Freud first discussed decathexis in relation to repression in the case of Justice Shreber whose repression had developed into paranoia.
the important role eventually attributed to energy in the very constitution of the psyche would make decathexis a central notion, independent of the mechanism of repression. (Paul Denis, "Decathexis" in Gale Cengage)
The term "decathexis" was never actually used by Freud though the concept it encapsulates is contained in Freud's discussion of "detachment of the libido," or "withdrawal of psychic energy." Psychic energy and libido are critical to the concept of decathexis and are defined as virtually synonymous terms though, for Freud, libido was exclusively sexual energy, which imbued all energy, while, for others, like Jung, psychic energy encompassed both sexual energy and other non-sexual forms of psychic energy. Psychic energy forms both cause and aim and is the repository of both personal experience and universal consciousness:
the definitions of psychic energy which Jung saw as having its source in the instincts, otherwise being comparable to and governed by the same principles as physical energy, with the exception that psychic energy has not only a cause but also an aim; the unconscious viewed as complementary to consciousness and functioning both as a repository of former personal experiences as well as universal images, referring to the way in which the unconscious communicates itself to consciousness, revealing the latent imagery which underlies and motivates an individual .... (Samuels, Shorter, Plaut. A Critical Dictionary of Jungian Analysis)
Decathexis is the reversal of a cathected state in which mental structures or objects are invested with libido or psychic energy, a process that begins in early (archaic) development stages so that parents are the earliest objects of cathexis. Cathexis is defined in Freudian psychoanalysis as the process of investment of mental or emotional energy in a person, object, or idea. Freud did not use the term "cathexis" himself, either, but rather used Besetzung, which has the meaning "interest" and which has several applications of meanings including "occupation" of territory by foreign forces and "charge" of electricity. Freud's reasoning in choosing Besetzung adds more layers of complexity to the concept of cathexis, a word of Greek origin chosen by translator James Strachey and a word that has raised criticism for being too esoteric (elitist) to replace Besetzung, a word of common German speech, though cathexis was adopted into the Freudian lexicon.
In cathexis, when it is a normal part of early stages of development, psychic energy or libido is invested in an object of attachment. To be "invested in" means to have psychic energy or libido devoted to an object that is then endowed with rights or powers of attachment and libido fulfillment. Cathectic investment may be in an object, a person or an idea ["a psychic formation, a bodily phenomenon, or an object" (Denis)]. Certain psychological phenomenon may trigger the withdrawal or reversal of cathectic investment, the simplest example of which is the loss of a person through death. Decathexis occurs through an elaborate and protracted process which entails, as Freud said, a "testing of reality" (Clewell) during which every memory of how "the libido is bound to the object [i.e., person during mourning] is brought up and hypercathected" (hypercathected: invested with excessive psychic energy or libido). It is through this "hyperremembering" process that the lost, decathected "object" can be invested with a new reality of absence after which the "ego becomes free and uninhibited again" (Freud, "Mourning and Melancholia," 1917, qtd by Clewell). The freed ego can then "reattached the free libido to a new object, thus accepting consolation in the form of a substitute for what has been lost" (Clewell).
The nature of decathected mental structures or objects, the more or less massive modalities of the decathexis, and the fate of the withdrawn energy, all would have serious consequences. As Freud writes: "the liberated libido will be kept in suspension within his mind, and will there give rise to tensions and color his mood" (1911c , p. 72), until it finds another attachment. (Denis, "Decathexis" on Gale Cenage)
Paul Denis. "Decathexis." International Dictionary of Psychoanalysis. Ed. Alain de Mijolla. Vol. 1. Gale Cengage, 2005.
Andrew Samuels, Bani Shorter and Fred Plaut. A Critical Dictionary of Jungian Analysis, Routledge: New York, 1986, qtd on C.G. Jung Institute of Chicago.
Tammy Clewell. "Mourning Beyond Melancholia: Freud's Psychoanalysis of Loss." Journal of the American Psychoanalytic Association.