Our research

We are motivated by the need to find better ways to treat and empower people suffering with mental health challenges

About psilocybin therapy

Psilocybin therapy is a new approach that is currently being investigated for the treatment of mental health challenges. It combines the pharmacological effects of psilocybin, a psychoactive substance, with psychological support.

Psilocybin is an active ingredient in some species of mushrooms, often referred to as ‘magic mushrooms’.  In order to investigate the effects of psilocybin as a potential treatment for depression and other illnesses, we have synthesised the compound to the highest regulatory standards in our psilocybin product, COMP360.

Early studies conducted in pioneering academic institutions have shown signals that psilocybin could be safe and helpful to patients with depression, anxiety, addiction and other mental illnesses, when administered with psychological support from specially trained therapists. This psychological or psychotherapeutic support consists of several preparation meetings with a dedicated therapist; support in the psilocybin therapy session itself; and integration sessions following the psilocybin experience. The timeline below shows some of the key developments in psilocybin research in the last few decades.


Sandoz chemist Albert Hofmann isolated and determined the structure of psilocybin


Launch of Indocybin (psilocybin)


Discontinued distribution of Indocybin due to misuse


Strassman et al, Journal of Psychopharmacology, First significant psychoactive trial (Di-Methyl-Tryptamine or DMT)

60 participants

Moreno et al, Clinical Psychiatry, Obsessive Compulsive Disorder

9 patients

Grob et al, Archives of General Psychiatry, Existential distress

12 patients

Johnson et al, Journal of Psychopharmacology, Tobacco dependence

15 patients

Bogenschutz et al, Journal of Psychopharmacology, Alcohol dependence

10 patients
Jul 2016

Cahart-Harris et al, The Lancet, Treatment-resistant depression

19 patients
Dec 2016

Ross et al, Journal of Psychopharmacology, Existential distress

29 patients
Dec 2016

Griffiths et al, Journal of Psychopharmacology, Existential distress

51 patients

We are running a comprehensive large-scale clinical development programme of psilocybin therapy for depression, including a phase IIb study for treatment-resistant depression, which is taking place across Europe and North America. For more information on our clinical trial, see ‘Our clinical trials’ below.

About treatment-resistant depression

‘Treatment-resistant depression’ (TRD) is a term used when people with depression do not respond adequately to at least two different anti-depressant medications.

Depression is the leading cause of disability and ill health worldwide. Up to two-thirds of people with depression do not respond to the first antidepressant medication they try. Up to a third of people with depression do not respond to multiple attempts at treatment.

Our clinical trials

Treatment-resistant depression study

We are running a randomised controlled trial of psilocybin therapy for treatment-resistant depression, taking place in a number of clinical trial sites across Europe and North America.

I suffer with depression

Recruitment to this trial is managed directly by the research teams at our trial sites, who work with specific eligibility criteria. In particular, only people who have tried two, three or four anti-depressants without success during their current episode of depression could be eligible to join – and this would need to be verified by your physician. If you think you might be eligible, please contact a study centre near you – locations are listed on the map below.

All sessions are conducted in the local language. Our sites in the Netherlands have regulatory permission to conduct sessions in English for non-Dutch speaking patients. Due to the time commitment required for study participation, only patients who live locally or have an easy commute to the study center, could be included in the study.

I am a clinician

We are actively recruiting patients with treatment-resistant depression at 18 sites in Europe and North America. This is a phase 2b randomized controlled study aiming to determine the optimal dose of psilocybin that is efficacious and well-tolerated. Patients will be randomized to a low (1mg), medium (10mg) and high (25mg) dose of psilocybin administered once with psychotherapeutic support by specially trained therapists.

All patients are required to have an ongoing therapeutic relationship with a healthcare provider who is familiar with the inclusion/exclusion criteria, willing to refer patients to the study and is able to provide the patient’s history with medical records.

Who is eligible for this study?

The study is open to patients with at least moderate to severe depression ages 18 yo and older in Europe and Canada, and 18-55 yo in the US, who failed 2, 3 or 4 antidepressant treatments for the current episode of depression.

If found eligible at screening, patients must be willing to come off current antidepressants and stay off for at least 2 weeks leading to the psilocybin session. The taper will be done by the study psychiatrist.  All patients and their families will be educated about the signs of antidepressant withdrawal and worsening of depression. Rescue medications are allowed at any time of the study. If patients are unable to tolerate the withdrawal and restart their antidepressants prior to the psilocybin session, they will be excluded from the study. If rescue treatment is initiated after the psilocybin session, patients will continue in the study as long as informed consent is maintained.

Until more research is available, the following patients are excluded from the study for safety reasons:

  1. Patients with history of psychotic illness, such as bipolar disorder, schizophrenia, and others
  2. Patients with Personality Disorders, such as Borderline, Schizoaffective and other personality disorders. Such disorders are difficult to diagnose and therefore confirmed history or clinical impression of a referring clinician is essential
  3. Recent (<1 y) history of substance abuse, including alcohol and illicit substances
  4. Patients with the history of uncontrolled hypertension and/or recent cardiovascular event, such as unstable angina, MI or CVS
  5. Patients with seizure disorder or uncontrolled insulin-dependent diabetes
  6. Depression due to life-changing medical illness

All sessions are conducted in the local language. Our sites in the Netherlands have regulatory permission to conduct sessions in English for non-Dutch speaking patients. Due to the time commitment required for study participation, only patients who live locally or have an easy commute to the study center, could be included in the study.

If you have a patient who may be suitable, please contact a study centre near you. Locations are listed on the map below, or visit ClinicalTrials.gov for a list of contact details.

If you a healthcare provider taking care of patients with TRD and would like to print out a reminder of inclusion/exclusion criteria, please click here.

Where is the study taking place?

For contact details of the centres near you, click on the map below, or visit: ClinicalTrials.gov 

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Click on your nearest city to find out more about their site
Aalborg, Denmark
Enhed for bipolar lidelse
Psykiatrien i Aalborg
Parc Sanitari Sant Joan de Deu
Sant Joan De Deu Serveis De Salut Mental
Institute Hospital del Mar of Medical Research (IMIM)
Institute of Neuropsychiatry and Addictions (INAD)
Clinical Research and Imaging Centre
Avon and Wiltshire Mental Health Partnership NHS Trust
Tallaght University Hospital
Adult Mental Health Service
University Medical Centre Groningen
University Centre for Psychiatry
Leiden University Medical Center
Department of Psychiatry
Kings College London
Institute of Psychiatry, Psychology & Neuroscience
Greater Manchester Mental Health NHS Foundation Trust
Department of Psychiatry
Northumberland, Tyne and Wear NHS Foundation Trust
Wolfson Research Centre, Campus for Ageing and Vitality
University Medical Centre Utrecht
Department of Psychiatry, Affective & Psychotic Disorders
Click on your nearest city to find out more about their site
North America
Mood and Anxiety Disorders Program
Emory University School of Medicine
Clinical Research Programs
Sheppard Pratt Health System
UT Center of Excellence on Mood Disorders
University of Texas Health Science Center at Houston
Kadima Neuropsychiatry Institute
Depression Evaluation Service
New York State Psychiatric Institute
Altman Clinical and Translational Research Institute
University of California, San Diego
Mood and Anxiety Section, Centre for Addiction and Mental Health
University of Toronto

Healthy volunteers study

In conjunction with the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London we ran a phase I, double-blind placebo-controlled study with 89 healthy volunteers, aged between 18 and 65 years.

Initial results of the study were presented at the ACNP 2019 annual meeting (see poster). The results showed that psilocybin was well-tolerated when administered to healthy adult volunteers with support from specially trained therapists (click here to read our press release).

Expanded access policy

We are currently conducting a phase IIb clinical trial of psilocybin therapy for treatment-resistant depression. We will not have the required preliminary efficacy and safety data to make a benefit-risk analysis until the end of this phase, at the very earliest, and so our psilocybin is not yet available under compassionate use.

COMPASS Pathways’ position on offering compassionate use of investigational medicines

We conduct clinical trials to assess the safety and efficacy of investigational medicines which, if proven, will allow us to obtain the necessary approvals from regulatory authorities to provide patients with access to these medicines. We believe that participating in clinical trials is the best way for patients to access medicines prior to approval.

In some circumstances, when this is not possible, patients with diseases or conditions may seek special access to investigational medicines outside of a clinical trial setting. These situations are typically referred to as compassionate use, but can also be known as expanded access, early access, pre-approval access and emergency use.

Through the clinical development process, a drug is rigorously tested for safety and efficacy in humans; if proven, it is submitted to regulatory authorities for approval for sale, and then made available through healthcare systems to as many patients in need as possible, as quickly as possible. Because we do not know during the clinical development whether the investigational medicine is safe or effective, compassionate use may present risks for both the patient and the clinical development programme. For patients, compassionate use may bring potential safety risks or a false sense that the medicine will provide benefit; for the clinical development programme, it can delay or jeopardise the approval of a new medicine sought by many.

We are responsible for ensuring the quality and integrity of our clinical trials and for minimising any risks to participants and possible future patients. When considering compassionate use of an investigational medicine, we consider many factors, such as the strength of the clinical data, the benefit-risk profile, the impact on the clinical development programme, the phase of development, and the probability and timing of regulatory approval.

A compassionate use programme, or a single request for compassionate use of an investigational medicine, can only be considered if the following conditions are met:

• There are no adequate alternative therapies or clinical trials available

• Sufficient preliminary efficacy and safety data exist for the therapy to enable COMPASS Pathways to make a benefit-risk analysis consistent with the establishment of a compassionate use programme. This would not occur earlier than the end of Phase IIb studies, and depending on the clinical programme, potentially even later

• Sufficient clinical data is available to identify an appropriate dose

• A patient’s treating physician and COMPASS Pathways’ Head of Clinical Development both believe there is potential for the patient to reasonably expect benefit from the treatment, and there is robust evidence to support the possibility that the patient will benefit from it

• Adequate supply exists to support both the ongoing clinical trials and approved compassionate use, until and if the product becomes commercially available

• The patient is not eligible for any of the COMPASS-sponsored studies of the treatment. Geographic limitations to participation in a trial would typically not mean a patient is ineligible

• Compassionate access will not adversely impact the clinical development programme, in particular, the conduct of a pivotal clinical trial that is required for regulatory approval

• The request must be made by the patient’s treating physician, unsolicited by COMPASS Pathways or any other individual or organisation

COMPASS Pathways will use the above criteria in consideration of whether to offer compassionate use. We cannot, however, guarantee that a compassionate use programme will be offered, and if it is offered, that the investigational medicine will be available to a particular patient.

Any pre-approval access to an investigational product must always comply with the applicable country-specific laws and regulations, including medicine importation requirements, and approvals must be secured from relevant regulatory bodies and the Institutional Review Board or Ethics Committee of the treating hospital.

For further information on our approach to compassionate use, please contact info@compasspathways.com.

Investigator-initiated studies

We are keen to further research that will change mental health outcomes and help those who have not been helped by other treatments. To support this, we work in collaboration with select academic institutions and researchers around the world. We provide our cGMP (clinical Good Manufacturing Practice – the highest manufacturing grade) psilocybin to researchers free of charge, in exchange for the right to use safety data. Researchers are expected to cover packaging and shipping costs with our logistics provider. For these investigator-instigated studies, we also provide support with regulatory submissions.

If you are interested in working with COMPASS through an investigator-instigated study, please contact us at info@compasspathways.com.


Collaboration is key to developing a new approach to mental health, and this is why we are bringing together health innovators for the benefit of patients.

Mindstrong Health delivers digital biomarkers of brain health. Its scientifically validated technology uses content-free, human-smartphone interactions to measure cognition and mood. We are working with Mindstrong Health on our treatment-resistant depression clinical trial to assess digital biomarkers as exploratory clinical endpoints.

Calm gives our therapists access to meditation content and training.

7Cups has developed a training bot which is used by our therapists to develop and practise their active listening skills.

Our research and development

We are committed to developing new innovative therapies that help people suffering with mental health conditions and ease the burden on healthcare systems. We are actively exploring additional indications for psilocybin and other new compounds.