Psychedelic-Assisted Mental Health Treatments Executive Summary

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Aidan Goth
Sjir Hoeijmakers
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Psychedelic-Assisted Mental Health Treatments

This is a summary of our cause area report on psychedelic-assisted mental health treatments. The full report can be found here.

Please note this executive summary and our original report were last updated in 2020. While our overall views remain unchanged, some details may be out of date.

Executive summary

Psychedelic drugs have the potential to revolutionise how we treat mental health conditions, from depression and anxiety to post-traumatic stress disorder (PTSD). So, how should philanthropists go about funding psychedelic-assisted mental health treatments? In this report, we answer this question, detailing the best projects to fund in this unique and promising space. The purpose of this research was to identify high-impact funding opportunities for people especially interested in improving the wellbeing of the current generation.

Psychedelic-assisted mental health treatments

In 2017, mental health problems, including substance use disorders, accounted for roughly 7% of the global disease burden, up from 4% in 1990. Despite how much suffering they cause around the world, for many mental health problems, the best treatments available only have a limited effect. For example, for major depressive disorder (MDD), antidepressants and the most effective types of psychotherapy each have an estimated average standardised effect size of less than one third. This is equivalent to reducing patients’ Hamilton Depression Rating Scale scores by about 1.6 points on average, on a scale that ranges from 0 to 50.

Psychedelic-assisted mental health treatments have the potential to change this. They could one day help reduce the global mental health burden and tackle the lack of adequate treatment. They involve ingestion of a psychedelic substance such as psilocybin or MDMA in a safe setting, supervised by trained therapists, and are often combined with preparatory sessions prior to the active treatment sessions and integratory sessions in the weeks following the treatment. Integratory sessions are non-drug psychotherapy sessions, which aim to address any difficulties that arose during or following the psychoactive sessions and to integrate lessons and understanding gained from these sessions into daily life. Psychedelic-assisted treatments are currently being tested for a variety of mental health problems, including major depressive disorder (MDD) and post-traumatic stress disorder (PTSD).

Intervention selection

Focusing on psychedelic-assisted mental health treatments, we identified three types of interventions to consider: direct treatment, academic research and drug development. Drug development is a process that covers everything from the discovery of a brand new drug for treatment to this drug being approved for medical use. Of the three interventions considered, drug development seemed the most promising. We focused on drug development in the United States, Canada, Israel, the European Economic Area and the United Kingdom, as we know of nonprofit organisations taking psychedelic-assisted mental health treatments through the approval process in these places.

Funding opportunity analysis

When investigating where philanthropists’ dollars could be put to best use, we considered funding opportunities at a nonprofit currently working on drug development: Multidisciplinary Association for Psychedelic Studies (MAPS). We had detailed conversations with this organisations and other experts, and surveyed the research literature on the psychedelic-assisted treatments it is advancing. We then determined how cost-effective this funding opportunity is.

MAPS is carrying out drug development for MDMA-assisted psychotherapy for PTSD in the US, Canada and Israel, and soon also in Europe.

MAPS recently announced its Capstone Campaign, with the aim of raising $30 million to make approval of MDMA-assisted psychotherapy a reality in the US, Canada and Israel and to start the commercialisation of this treatment. MAPS secured $10 million of initial funding and a $10 million matching pot to be unlocked if the remaining $10 million is secured. Soon after we evaluated this funding opportunity, its funding gap was filled, so we turned our attention to MAPS’s drug development programme in Europe.


We think MAP’s drug development programme and Capstone Campaign for the US, Canada and Israel is similarly as impactful as our recommendations in other areas in the mental health and subjective wellbeing spaces, such as Action for Happiness’ scale-up of their local community course and StrongMinds’ treatment of women with depression. We recommend giving to the drug development programme alongside these other recommendations, especially if you are interested in ‘riskier’ interventions; though this funding opportunity has now been filled.

We think that MAPS’s drug development programme in Europe is less cost-effective than the Capstone Campaign. This judgement is driven partly by our cost-effectiveness models, which suggest that the European campaign is around one quarter as cost-effective as the Capstone Campaign. Additionally, we expect the wider benefits of MAPS’s European drug development programme to be smaller than those of the Capstone Campaign as approval will come later in Europe and the first major approval will likely have the greatest wider benefits. Therefore, we think that the European programme presents a good funding opportunity for donors with a special interest in psychedelic-assisted mental health treatments but we would recommend it only in certain circumstances.

Funding opportunities vs nonprofits

To avoid confusion, especially when we are ranking funding opportunities in a particular cause area, we think it important to emphasise the difference between evaluating funding opportunities and nonprofits. Our research conclusions do not imply that one nonprofit does more important work than another, or that a particular cause is more worthy of support than another. They instead reflect our overall view of which funding opportunities at nonprofits could currently use extra funds most effectively.

This is because we aim to recommend to our members funding opportunities with a maximum counterfactual impact. That is, our goal is to recommend opportunities where extra funding by our members would make the largest difference compared to if they provided no extra funding. Paradoxically, this implies that if a nonprofit does high-impact work but is in addition very successful at raising funds for that work, we should not recommend any funding opportunities at that nonprofit.

In the case of this research project, our current best guess is that MAPS is doing high-impact work. However, one reason why we do not recommend MAPS’s European drug development programme as highly as other funding opportunities in the mental health and subjective wellbeing space is that MAPS has an exceptional fundraising track record.

Aidan Goth


Aidan is a former Researcher at Founders Pledge. Previously, he studied at the University of Oxford. He graduated with a First Class MMathPhil in Mathematics and Philosophy, specialising in formal epistemology, decision theory and ethics.

Sjir Hoeijmakers


Sjir is Director of Research at Giving What We Can, having led research and efforts to create the Patient Philanthropy Fund in his previous role as Senior Researcher at Founders Pledge. He also co-founded Effective Altruism Netherlands, where he serves as a trustee.