Evaluating the Feasibility, Clinical Effects, and Safety of Psilocybin-assisted Psychotherapy for Treatment-resistant Obsessive-compulsive Disorder: An Open-label Clinical Trial
Psilocybin, the chemical component of magic mushrooms, has been administered with psychotherapy in several randomized clinical trials (RCTs) showing large and sustained antidepressant effects. There is interest to see if similar effects may be provided in those with obsessive compulsive disorder (OCD). The purpose of this study is to evaluate the safety, feasibility, and clinical effects of psilocybin administration in those with OCD. Ten participants with treatment-resistant OCD will receive two doses of 25mg of psilocybin under supportive conditions, two weeks apart. The investigators hypothesize that two sessions of psilocybin 25mg administered under supportive conditions to participants with treatment-resistant OCD will lead to significant reductions in OCD symptoms.
• Adults 18 to 65 years old;
• Are outpatients
• Must be deemed to have capacity to provide informed consent;
• Must sign and date the informed consent form;
• Stated willingness to comply with all study procedures;
• Ability to read and communicate in English, such that their literacy and comprehension is sufficient for understanding the consent form and study questionnaires, as evaluated by study staff obtaining consent;
• Primary The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnosis of obsessive compulsive disorder (OCD) based on medical records and assessment using the Structured Clinical Interview for DSM-5 (SCID-5) administered at the first screening visit;
• Participants diagnosed with treatment-resistant OCD defined as individuals with a score of ≥ 16 on the YBOCS (i.e. moderate symptom severity) and that have not responded to two or more separate pharmacological interventions and one or more trials of cognitive behavioural therapy (CBT); there is no upper limit on the number of treatment failures;
• Individuals with an estimated glomerular filtration rate (eGFR) above 40mL/min/1.73m2 and all blood work within normal limits as assessed by clinical laboratory tests at Screening (V1)
• Ability to take oral medication;
• Individuals who are capable of becoming pregnant: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method during study participation;
• Individuals who are willing to and have tapered off current OCD medications for a minimum of 2-weeks prior to Baseline (V2) and whose physician confirms that it is safe for them to do so;
• Individuals who are willing to and have tapered off current inhibitors of 5'-diphospho-glucuronosyltransferase (UGT)1A9 and 1A10, aldehyde dehydrogenase inhibitors (ALDHs) and alcohol dehydrogenase inhibitors (ADHs) for a minimum of 2-weeks (or more depending on the medication) prior to Baseline (V2) and for the duration of the study and whose physician confirms that it is safe for them to do so; and
• Agreement to adhere to Lifestyle Considerations (section 4.5) throughout study duration.