La thérapie Intégration du Cycle de Vie (Lifespan Integration) est une approche novatrice développée en 2002 par Peggy Pace, qui s'adresse à des sujets qui ont vécu un traumatisme ou qui présentent des troubles anxieux et des difficultés à réguler les émotions. Apparues vers 2012 en France notamment avec les travaux de Joanna Smith, les recherches sur son efficacité sont encore peu développées. La question des effets des interventions du thérapeute ICV reste à explorer. Dans le cadre du paradigme du Change Process Research et suivant la méthodologie de l'étude de cas pragmatique, nous avons voulu identifier, décrire et expliquer les processus de changement que permet cette approche novatrice à partir de six thérapies terminées. Un entretien de follow-up a permis de recueillir le point de vue des patients sur leur propre changement et de retrouver les événements significatifs dans les séances de thérapie qui avaient été enregistrées. Des mesures ont été effectuées tous les six mois : (1) la Difficulties Emotion Regulation Scale (DERS-f) pour les difficultés de régulation émotionnelle, (2) le Penn State Worry Questionnaire (PSWQ) pour le trouble d'anxiété généralisée et (3) le State Trait Anxiety Inventory (STAI) pour l'anxiété-trait. Dans cet article, nous présenterons l'étude de cas pragmatique d'une patiente âgée de 32 ans, qui présentait un trouble d'anxiété généralisée. La thérapie ICV a duré 18 mois, avec 34 séances et a permis non seulement de diminuer l'anxiété mais également d'améliorer la qualité de la régulation émotionnelle. Les limites de cette étude seront abordées ainsi que des préconisations pour la pratique. Lifespan Integration therapy is an innovative approach developed in 2002 by Peggy Pace, initially for people who have experienced trauma or who have anxiety disorders and difficulties in managing emotions. It first appeared in France around 2012, notably with the work of Joanna Smith, but research on its effectiveness is still lacking. The question of the effects of a Lifespan Integration therapist's actions remains to be explored. Lifespan Integration therapy is based on numerous neurobiological postulates (polyvagal theory or TPV, autobiographical memory and self-defining memories, implicit memory, traumatic memory and Multiple Trace Theory or MTT, etc.). It is also based on the attachment theory while integrating theoretical concepts from the systemic theory (trigenerational, loyalties, resonances, etc.). It is therefore a therapy that could be described as integrative, based on the bottom-up circuit rather than on the top-down one, like most so-called "talk" therapies. Within the framework of the Change Process Research paradigm and according to the methodology of the pragmatic case study, we wanted to identify, describe, and explain the processes of change that this innovative approach allows. Our study is based on 6 completed therapies. In this article, we will present a pragmatic case study of a 32-year-old female patient, who had a generalized anxiety disorder at the beginning of therapy. Her Lifespan Integration therapy lasted 18 months, with 34 sessions and resulted not only in a decrease in anxiety but also in an improvement in the quality of her emotional management. Measures were completed every six months: (1) the Difficulties Emotion Regulation Scale (DERS-f) for emotion regulation difficulties, (2) the Penn State Worry Questionnaire (PSWQ) for generalized anxiety disorder, and (3) the State Trait Anxiety Inventory (STAI) for traits of anxiety. We applied the pragmatic case study (Fishman, 1999) to determine the processes of change and to identify the pivotal moments of psychotherapy. A follow-up interview was used to explore the patients' perspectives on their own improvement and to trace significant events in the recorded therapy sessions. It was carried out by another psychologist in order to reduce any biases related to the dual role of "therapist-researcher". The results of the questionnaires show a significant improvement in the symptoms of GAD, a very clear improvement in the subject's emotional management, which is accompanied by a decrease of the symptomatology. All the dimensions assessed with the DERS-f were initially affected except impulsivity. After six months of psychotherapy, all the dimensions gradually reached the norm. Moreover, significant events during the therapeutic process were noted by the client during the follow-up interview, highlighting the pivotal moment of the psychotherapy. Indeed, it was after having carried out the first phase of the therapy, based on the consolidation and reconsolidation of the memory, that we were able to approach, with the subject's consent, the event that might have been at the origin of the GAD: her uncle's death when she was six. We then carried out a standard protocol on this event. This is a protocol which consists of revisiting the scene of the memory in the company of the adult-self coming to support the child-self in the various phases structuring this protocol until there is a calming of the various parts of the self. We can thus note that it is precisely following this session that the emotional regulation, already clearly improved, was found to return to the norm. This very significant improvement in emotional regulation continued during the next phase of the therapy. Lifespan Integration Therapy has reported important clinical outcomes to date, but the studies have not yet been sufficiently developed. It would be interesting to extend this research to a larger population in order to validate the different effects observed in this clinic as demonstrated by Reijil & al in 2020. Additional studies, particularly investigating sleep and eating disorders, would be welcome. Indeed, we have observed a significant effect on these different domains, which seems to be evident from the moment that emotional regulation becomes effective, and precisely because emotions are involved in these functions. [ABSTRACT FROM AUTHOR]