“So many relationships in the room”: Participant perspectives on the affordances and challenges of co-therapy in psychedelic assisted therapy

Psychedelic-assisted therapy (PAT) frequently utilises a “cotherapy” model, in which two therapists jointly support participants or patients through preparation, dosing, and integration sessions. While common in clinical trials, the experience of cotherapy from the participant perspective remains underexplored. This qualitative study examined experiences of cotherapy within a trial of psilocybin-assisted therapy for generalised anxiety disorder. Semi-structured interviews with 18 participants (29 interviews in total) were analysed thematically, guided by Affordance Theory to consider how cotherapy dynamics shaped therapeutic possibilities. Three major themes were developed: (1) Dose day cotherapy: safety, trust and the realities of access; (2) Cotherapy influences therapeutic processes; (3) Cotherapy shapes the impact and credibility of therapeutic insights.Together, these findings position cotherapy in PAT as both a safety and supportive measure, and a potentiator of therapeutic processes. In the context of a single site with high levels of clinician qualification and training, participants generally valued cotherapy. Insights from this study can guide clinical practice and future research, so that feasibility and accessibility are enhanced while preserving the safety and therapeutic benefits afforded by cotherapy.