Date of Award

Spring 2024

Embargo Period


Document Type

Master's Thesis

Degree Name

Master of Arts (MA)


Department of Psychology


Clinical Psychology

First Advisor

Mitch Earleywine

Committee Members

Mitch Earleywine, Drew A. Anderson


Millions of Americans struggle with posttraumatic stress disorder (PTSD) every year. Though typical treatments work for some, patients often drop out of treatment. Given that patients are often retelling their traumatic experiences, or confronting stimuli and situations that are relevant to the experience, psychotherapy for PTSD can be psychologically demanding and intensive. These factors provide a further understanding for the high rates of PTSD treatment attrition. Psychedelic assisted psychotherapy (PAP) is a potential option to mitigate these concerns. Preliminary research on PAP has revealed effective and promising results. However, questions about PAP and their public perception remain. Furthermore, treatment expectancies, or an individual’s expectation of treatment efficacy, may help inform treatment efforts. The current study examined expectancies related to psychedelic use and PTSD symptoms. A total of 434 individuals participated in the study and completed measures via an online survey. Paired sample t-tests revealed that several expectancy means differed significantly from each other, with expectancies for numbing receiving the highest score and reexperiencing receiving the lowest score. A zero-inflated negative binomial regression indicated that, in general, participants expected psychedelics to slightly worsen their overall symptoms. Additionally, participants experiencing greater PTSD symptoms reported more negative expectancies. However, results varied when looking at specific expectancy groups, with some findings indicating more positive expectancies. Overall, these findings offer various implications; however, the field needs more research to fully understand the facets that influence psychedelic use expectancies.


Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.