Major depressive disorder (MDD) is one of the most prevalent disorders that affects people globally. It’s important to understand the efficacy of treatment to help patients suffering from it,...Show moreMajor depressive disorder (MDD) is one of the most prevalent disorders that affects people globally. It’s important to understand the efficacy of treatment to help patients suffering from it, especially treatment-resistant depression (TRD) patients. Understanding change through therapy is one way to understand the efficacy. In this paper, a search for response shift has been performed to identify it in psychedelic therapy. Response shift (RS) is a phenomenon of change in a person’s internal standards. It affects the results of self-report assessment methods and thus the conclusions drawn from it, by accounting for internal changes. Which could be helpful in providing insight into the change patients are going through internally. This paper uses data from a trial comparing psilocybin and escitalopram for depression. Data was analysed using Structural Equation Modelling (SEM) to identify the presence of response shift. Based on the results of the analysis the hypothesis of “RS is present with MDD patients’ PROs after receiving psychedelic therapy with either escitalopram or psilocybin at 6 weeks” was rejected. There was no significant difference between the measurement model and the response shift model which indicated the lack of presence of response shift. These results are a starting point to rule out RS from psychedelic therapy which could help with future interpretations of the topic. However, more research in the area could help confirm these results as there is no published previous research to further support the results.Show less