An anonymous Bitcoin philanthropist has pledged to match any donations to a research project investigating the health benefits of MDMA, up to the value of $4m (£2.9m).

In what is believed to be the largest philanthropic cryptocurrency donation ever, The Pineapple Fund will run the fundraiser for the US-based Multidisciplinary Association for Psychedelic Studies (Maps) until 10 March 2018. The unnamed donor will then convert Bitcoin into US dollars to match all new donations to Maps during this period.

Founded in 1986, Maps hopes to prove that the psychoactive substance MDMA can be used in a controlled setting by doctors to treat post traumatic stress disorder (PTSD) and other mental illnesses. MDMA is commonly used as a party drug, where it is often cut with harmful substances. Maps does not therefore condone using MDMA outside of a medical setting.

The money will enable Maps to fund its upcoming phase three clinical trials, which it estimates will cost $26m. If their theories are proven this would allow Maps to apply to the US Food and Drug Administration for approval – potentially transforming the lives of PTSD sufferers.

In August 2017, the FDA granted Breakthrough Therapy Designation to MDMA-assisted psychotherapy, acknowledging it "may demonstrate substantial improvement over existing therapies".

The move comes after the benefactor behind The Pineapple Fund gave Maps 59 Bitcoins – at the time equivalent to $1m – in mid-December 2017. Maps cashed in the donation into US dollars immediately, Brad Burge, communications director of Maps, told IBTimes UK at the time. Days later, another anonymous donor gifted the organisation 51.54 Bitcoins, followed by 88,000 Lunyr tokens worth over $769,000 from a separate unidentified cryptocurrency philanthropist.

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"PTSD is a severe condition that affects everyone from sexual assault survivors to military veterans," wrote Pine, the Pineapple Fund's founder.

"Existing treatments have so much room for improvement, and MDMA-assisted psychotherapy has shown great promise. We're offering the matching grant because we think the psychedelic and cryptocurrency communities can work together to finish funding Phase 3 clinical trials," Pine added.

The Pineapple Fund last year announced its intentions to give away $86m in Bitcoin to charities and causes around the world.

It has also gifted $1m worth of Bitcoin to healthcare crowdsourcing platform Watsi, sanitation charity The Water Project and the Eff, which names and shames US government officials and agencies lacking transparency.

"I remember starting at bitcoin a few years ago. (...) Bitcoin has changed my life, and I have far more money than I can ever spend. My aims, goals, and motivations in life have nothing to do with having XX million or being the mega rich," the philanthropist wrote on Reddit. "So I'm doing something else: donating the majority of my bitcoins to charitable causes. I'm calling it The Pineapple Fund."