Psychosomatic investigation is centred on the analyst's exploration of the functional capacities of the patients' mental cathexes in order to encourage the emergence of psychosomatic knots during the encounter. A lack of lived experience of early sensual regression is at the root of a certain precariousness in their mental functioning, involving a rigidification of their defensive capacities. The analyst must therefore be careful to avoid the onset of a somatic disorganization instead of promoting a psychic après-coup following the exchanges.