Psilocybin-assisted Therapy for Post-Traumatic Stress Disorder in Survivors of Intimate Partner Violence

The goal of this randomized controlled trial is to evaluate the efficacy of psilocybin administered with Acceptance and Commitment Therapy (ACT) as an intervention to reduce post-traumatic stress disorder (PTSD) symptom burden in adult (aged 18-65) survivors of intimate partner violence (IPV).

This trail will test the following 2 aims:

AIM 1 : To compare the efficacy of a therapeutic psilocybin dose at improving outcomes on the PCL-5 and CAPS-5 as compared to an active control psilocybin dose in IPV survivors with chronic PTSD.

AIM 2: To evaluate the efficacy of psilocybin on quality of life, cognitive function, motor ability, depression, anxiety, and cognitive flexibility.

Participants will be asked to:

* Complete a 2 part screening process
* Attend a baseline assessment
* Complete a psychoeducation preparation session(s)
* Attend psilocybin administration session (receive high dose \[25mg\] or low dose psilocybin \[1mg\])
* Complete 5-6 weekly sessions of ACT
* Repeat outcome measures at 1-week, 4 weeks, 3 months (online questionnaires only), and 6 months post-psilocybin administration.

The overall objective of this study is to evaluate the efficacy of psilocybin administered with Acceptance and Commitment Therapy (ACT) as an intervention to reduce post-traumatic stress disorder (PTSD) symptom burden in survivors of intimate partner violence (IPV).

This trail will test the following 2 aims:

AIM 1 : To compare the efficacy of a therapeutic psilocybin dose (25mg) at improving outcomes on the PCL-5 and CAPS-5 as compared to an active control psilocybin dose (1mg) (allocation ratio 1:1) in IPV survivors with chronic PTSD. Mean baseline scores will be compared to scores at each follow-up timepoint (1-week, 4 weeks, 3 months (PCL-5 only), and 6 months post-psilocybin administration).

AIM 2: to evaluate the efficacy of psilocybin on quality of life, cognitive function, motor ability, depression, anxiety, and cognitive flexibility. Mean baseline scores will be compared to scores at each follow-up timepoint (1-week, 4 weeks, 3 months (online only), and 6 months post-psilocybin administration).

The secondary efficacy outcomes will include measures of mood, anxiety, post-traumatic stress, cognitive flexibility, emotional regulation, and quality of life.

Exploratory Aim: Exploratory objectives of this study include evaluating blood biomarkers reflective of inflammation, growth factors, brain injury, and oxidative stress relevant to PTSD and psilocybin's mechanisms of action.

A total of 76 male and female patients between the ages of 18-65 with the last incident of IPV greater than 6 months prior with a score of 1 on the Composite Abuse Scale with repetition of abusive events, meeting DSM-5 criteria for PTSD and a minimum PCL-5 score of 33.

All patients will undergo a thorough, 2-part screening procedure. Eligible participants will be randomly allocated 1:1 to either the high dose (38 participants) or low dose (38 participants) psilocybin groups. All participants will be asked to attend a baseline session consisting of clinical and behavioural outcome measures followed by a pre-dosing psychoeducation session. Following the single dosing session, participants will complete 5-6 weekly ACT sessions. Outcome measure assessments will be repeated at 1-week, 4 weeks, 3 months (online only), and 6 months post-dosing.

Eligibility Criteria:
Inclusion Criteria:

* Individuals of all sexes, gender identities, and ethnicities
* Ages 19 to 65 years at the time of screening
* At least 6 months since last IPV incident
* A score of 1 on the Composite Abuse Scale with repetition of abusive events
* Minimum PCL-5 score of ≥ 33
* Limited lifetime use of serotonergic hallucinogens
* Ability to read/write English

Exclusion Criteria:

* Severe or moderate substance use disorder other than nicotine in past 6 months
* Lifetime diagnosis of schizophrenia or bipolar disorders (or first or second-degree relative)
* Active suicidal ideation or serious attempt within the past 1 year.
* Current pregnancy or nursing, trying to become pregnant
* Any notable abnormality on ECG or routine medical blood laboratory test
* Insulin-dependent diabetes; if taking oral hypoglycemic agent, then no history of hypoglycemia
* Epilepsy with a history of seizures
* Current or recent (within 12 weeks) participation in a clinical trial
* Cognitive impairment (SLUMS score \<20)
* Suffered a moderate/severe TBI at least once in lifetime
* Suffered a mild TBI within the last 6 months
* Any other circumstances that, in the opinion of the investigators, compromises participant safety
* Not compelled to enter treatment to avoid legal consequences