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Australian Clinical Trials

Clinical Trial Details

Psilocybin-assisted psychotherapy for Generalised Anxiety Disorder

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Trial Information

Broad Health Condition Mental Health

Specific Health ConditionAnxiety

Trial FocusTreatment

Recruitment Details

Recruitment status

Recruitment State


Anticipated date of first participant enrolment10/01/2022

Anticipated date of last participant enrolment12/09/2023

Phase of TrialPhase 2

Has the study received ethics approval?Further information iconApproved

Trial summary

Psilocybin-assisted psychotherapy has demonstrated excellent safety and efficacy in the treatment of depression, substance use disorders, and mental ill-health related to terminal illness. Many patients in these trials have reported rapid, large, and persistent decreases in symptoms of anxiety, suggesting utility in treating anxiety disorders with psilocybin-assisted psychotherapy. However, the impact of this treatment for people with GAD is unknown. In this study, we will complete a randomised controlled trial to test a 7 week (2 dose) psilocybin-assisted psychotherapy for the treatment of GAD. 72 individuals will be randomly assigned to receive two doses either psilocybin (25mg or 30mg, oral) or placebo (diphenhydramine, 75mg or 100mg, oral) with three weeks between doses. All participants will receive psychotherapy before, during, and after dosing sessions. A variety of measures will test for safety and efficacy of the treatment. The primary outcome measure investigates change in clinician-rated symptoms of anxiety. A range of secondary and exploratory measures probe changes in disability, quality of life, comorbid psychiatric and addictive symptoms, baseline and acute predictors, as well as participant-rated acceptability, appropriateness and feasibility of the treatment. 


Key inclusion criteria

*Adults experiencing severe GAD. 
*Proficiency in English.
*Provide a contact (relative, spouse, close friend or other Support Person) who can transport and provide support to participant following two or three experimental sessions.
*Taper and cease of certain excluded medications is deemed appropriate, agreeable, and under supportive care, and successful following confirmation of preliminary enrolment. Note, prospective participants are not required to taper and cease prior to preliminary enrolment.
*Agree to all study-related requirements.

Minimum age18 Years

Maximum age75 Years

GenderBoth males and females

Can Healthy volunteers participate? No

Key exclusion criteria

*Contraindicated medical conditions including cardiovascular conditions, major CNS disease, hepatic dysfunction, hypercalcaemia risk, epilepsy/seizures, renal insufficiency, diabetes, and hypothyroidism.
*Weigh less than 48 kilograms or BMI < 17. 
*Are pregnant or nursing, or able to become pregnant and are not practicing permanent or double-barrier birth control methods.
*Taking a contraindicated medication that cannot be ceased for an appropriate length of time during the trial. 
*Extremely severe depression, anxiety, suicidality or other psychiatric symptoms that would warrant hospitalisation, as determined by the screening psychiatrist in a clinical interview.
*Current or past history of meeting DSM-5 criteria for certain excluded psychiatric indications.
Contact details and further information

Sponsor Primary Sponsor Type: University
Primary Sponsor Name: Monash University
Primary Sponsor Address: Wellington Rd, Clayton, Victoria 3800
Primary Sponsor Country: Australia

Trial IDACTRN12621001358831


Contact person for information and recruitmentDr
Paul Liknaitzky
Monash University 770 Blackburn Rd, Clayton, Victoria, 3168
+61 3 9905 2038

Email contact Further information