This paper aims at re-conceptualising the notions of regression and trauma in the light of the concept of the construction of trauma. Through the exam of a clinical case, the author tries to show how the unconscious of patient and analyst meet in a deep analytic process and how the intersubjective field emerges. The analysis of countertransference and of processes regarding the intersubjective field, together with the analyst facilitating attitude, contribute to promote regression, meant as a privileged channel to reach pre-mental level and to come close to the state in which the shock situation - meant as trauma forerunner - is produced. The author supposes that trauma, i.e. the expression of a secondary process, is a form of Nachträglichkeit and is indeed the result of a psychoanalytic construction which resembles transitional processes and is based on the intermediate area function.
Keywords: Regression, shock, trauma, trauma construction, intersubjective field, compulsion to repeat