Today, my colleagues and I published a paper investigating the negative outcomes of psychedelic-assisted therapy. Our findings revealed not only short-term negative reactions to psilocybin dosing sessions, such as physical, cognitive, and emotional reactions, but also long-term negative effects that are even more concerning. These include destabilization, where clients’ defense or avoidance mechanisms are disrupted, leading to decreased coping abilities, and complications in the treatment relationship, such as dependency and blurred professional boundaries. While the potential of psilocybin to alleviate treatment-resistant depression is promising, our research urges caution, highlighting that the negative effects of these treatments remain understudied and potentially significant.