Diagnosis in Gestalt therapy has historically been rejected. In Gestalt therapy the notion of the diagnosis of personality or mood disorders as being depersonalising and anti-therapeutic, in that, it objectifies the client rather than sees the client as fluid and unique. For this reason Gestalt methodology relies on intrinsic aesthetic diagnosis, which is, the moment to moment interactions of the therapist/client relationship at the contact boundary, using the phenomenological method, as applied to Gestalt therapy. That is, to observe-bracket-describe, in an effort to stay experience near, by focusing on the here and now, whilst bracketing any interpretation, so that the client can discover their own understanding and meaning of their experiences.
Phenomenological observation is descriptive and flexible, rather than simply defining, it is an attempt to see patterns, themes and repetitions in the body, movement, voice and use of language that are unique to the client. Attention is given not to the figure that imposes itself, but to what is related to it in the background. Thus, interventions by the therapist arise from blocks in contact and it is within the therapeutic relationship that the client and therapist co-construct the diagnostic process, pooling together the knowledge (and foreknowledge) of the therapist and client.
Primarily Gestalt diagnosis is an assessment of the person-world situation, that is, a field diagnosis, where both ordered and disordered interactions are understood as a self-organising process of the situation. It is “….. an understanding or assessment of all the ways the client makes meaning and contact with their world” (Joyce & Sills, 2010, p. 58).