BackgroundIn this article, we aim to describe an interdisciplinary model for psychedelic assisted psychotherapy (PAP) that we have developed at the Geneva University Hospitals, in an institutional setting. Our model integrates the collaborative efforts of psychiatrists, psychologists, and nurses establishing a structured framework for administering PAP in a safe, controlled, and standardized manner. IntroductionPsychedelic assisted psychotherapy (PAP) is a psychotherapeutic approach that utilizes the profound alteration of the state of consciousness induced by psychedelic substances to enhance therapeutic outcomes. This innovative approach, which has been neglected due to historical biases rather than empirical evidence, is now experiencing a renewed interest among clinicians. Contemporary research, equipped with advanced methodologies and a rigorous scientific approach, is showing significant therapeutic potential for a range of mental health disorders. In Switzerland, the legal framework authorizes the medicinal use since 2014 for exceptional authorizations for the medicinal use of LSD and psilocybin for therapeutic purposes, under strict regulations. MethodWe provide a comprehensive description of the PAP protocol implemented at the Geneva University Hospitals, beginning with its inception in September 2020. Our methodological outline includes the administrative and clinical selection criteria for patient eligibility; the preparatory sessions designed to introduce the patients with psychoeducation interventions and the analysis of intention and therapeutical objectives; the controlled administration of psychedelics in a supportive environment; and the integration sessions that follow psychedelic experiences. Our protocol emphasizes safety, ethical considerations, and the importance of a supportive therapeutic relationship throughout the process. We also describe questionnaires we use to qualify and assess the alteration in the state of consciousness, namely The Five Dimension Altered States of Consciousness (5AD-ASC) and the Mystical Experience Questionnaire (MEQ). Since the start of the program in September 2020 and up to February 2024, a total of 224 personal authorizations (114 LSD, 110 Psilocybin) have been issued to the Geneva University Hospital PAP team, for a total of 396 individual sessions. DiscussionThe core argument presented in this article is that the psychedelic-induced alteration of consciousness is a novel therapeutic tool, which works as a potent catalyst that can be synergistically combined with traditional dialogue-based psychotherapy. This combination has the potential to support the psychotherapeutic processes and enable breakthroughs in cases where conventional therapy has reached its limits. We discuss the implications of this approach, reflecting on both its challenges and its transformative potential within its clinical application. ConclusionThe conclusion of our article is an endorsement of the continued basic and clinical research on PAP. By presenting a detailed framework of the PAP process, including its preparatory, experiential, and integrative phases, we advocate for a structured and scientifically grounded exploration of its therapeutic efficacy. Our conclusion calls for a broader acceptance and integration of PAP within clinical practice, provided it is underpinned by ongoing research, ethical practice, and institutional support.