The Borromean clinic is a model of psychoanalytic practice advanced in the late work of Jacques Lacan.
The Lacanian model describes the 3 rings that make up that knot at the Imaginary, the Symbolic, and the Real.
The interconnectedness of all 3 is crucial to perceiving reality accurately, and cutting the ties of a single ring causes the others to also become disconnected, resulting in a disturbed perception of reality and possibly psychosis.
[1] In 1975, Jacques Lacan added a fourth ring to his theory which the conclusion that the fourth ring was responsible for locking up the psyche.
[1] Jacques was also a strong believer in Sigmund Freud's work and was heavily influenced by Freud's original work in psychoanalytic theory.