Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant


Physician Assistant Studies

Department Chair

John Cavenagh, MBA, PhD, PA-C


OBJECTIVE: The objective of this selective Evidence Based Medicine (EBM) review is to determine whether or not “Are psychedelics effective in treating anxiety associated with a lifethreatening disease?”

STUDY DESIGN: Review of two double-blind, randomized, placebo-controlled pilot studies and one randomized controlled trial (RCT).

DATA SOURCES: All studies were published in peer-reviewed journals found via the use of PubMed Database.

OUTCOMES MEASURED: The outcome measured in this EBM was the effect of psilocybin or LSD on the reduction in anxiety. Reduction in anxiety was measured using either the Hamilton Anxiety Rating Scale (HAM-A) or the State-Trait Anxiety Inventory (STAI). Participants subjectively rated their anxiety pre- and post-drug administration.

RESULTS: The results of each study reached statistical significance, indicating psilocybin or LSD to be an effective form of treatment for anxiety in patients with a life-threatening disease. The study by Gasser et al. showed a significant reduction in state anxiety from baseline to 2 months post-LSD administration (p = 0.021). Grob et al. showed a significant decrease in trait anxiety at the 1-month (p = 0.001) and 3-month (p = 0.03) follow-ups after psilocybin administration. Lastly, Griffiths et al. found that 76% of patients administered high-dose psilocybin had a >50% reduction in their anxiety 5 weeks after treatment as compared to 24% of those participants in the control group, with a number needed to treat (NNT) of 2.

CONCLUSION: Both pilot studies and the RCT included in this review indicate that LSD or psilocybin are an effective treatment for anxiety associated with a life-threatening disease.