Classic psychedelic studies involve interpersonal interactions with participants before, during, and after the acute effects of psychedelics. In the field of psychedelic research, there is currently a debate about whether this interpersonal interaction is most accurately considered “psychological support,” “psychotherapy,” or something else. Proponents of the psychological support label describe the interpersonal interaction in most classic psychedelic studies as aimed at safety, while proponents of the psychotherapy label argue that the interpersonal interaction involves intervening on psychotherapeutic processes that not only support safety, but also contribute to treatment efficacy. However, we believe that the debate has so far been largely unproductive due to a lack of shared definitions or criteria for the relevant interpersonal interactions. Here, we propose definitions and criteria for two viable forms of interpersonal interaction in psychedelic administration: one directed solely towards safety (psychological support) and one directed towards both safety and efficacy (psychotherapy). We then trial our proposed criteria on a sample of 11 published classic psychedelic clinical trials. Our procedure categorized 10 out of 11 studies as being more or less consistent with psychological support or psychotherapy, but achieved clear distinctions in only 4 out of 11 studies. Given these findings, we argue that higher quality data on the interpersonal interaction is needed to clearly distinguish between psychological support and psychotherapy. We conclude by suggesting ways that our criteria can be used in the future to empirically test the relative safety and efficacy of psychological support vs. psychotherapy in psychedelic medicine.