"Doc, I am ready to play ball."
Psilocybin is an hallucinogenic drug
It had been years since Jeremy (not his real name) had touched a basketball.
Living with obsessive-compulsive disorder (OCD), Jeremy feared contamination from dirt and germs which prevented any part of his body from touching the ground, save for the soles of his shoes.
But whilst taking part in a small clinical study to investigate the effects of psilocybin, the hallucinogenic compound found in 'magic' mushrooms, on people with OCD, Jeremy's bare feet lay on the floor and he expressed a willingness to engage in an activity, playing with a ball, that just hours before he would have been considered abhorrent.
Although Jeremy's symptoms gradually returned, other patients also experienced transient relief from their OCD symptoms and one entered an extended period of remission lasting more than six months.
Lead researcher Dr Francis Moreno, associate professor of psychiatry at the University of Arizona, Tucson, said: "I really think that participating in the study influenced the patient's remission."
It was the first to investigate the therapeutic benefits of psilocybin to be published for more than 30 years.
But critics say the study's flawed methodology means that conclusions cannot be made about the drug's efficacy against OCD, and some question whether it should have taken place at all.
Professor Jeffrey Schwartz, of the University of California, Los Angeles, said: "This study is going to receive a lot of attention and it will create a desire on behalf of a patient population that is suffering and hoping for a 'magic bullet'."
However, the study's authors say that the primary purpose of the study was to demonstrate safety.
Dr Moreno said: "If the question is: 'did we find enough information to support exploring this further?', then we got some interesting findings which support the need for a proper controlled study."
There are an estimated six million OCD sufferers in the US, making OCD the fourth most commonly diagnosed psychiatric disorder after phobias, depression and alcoholism.
OCD is associated rituals, such as handwashing
OCD is an anxiety disorder characterised by the repetitive or ritualistic performance of behaviours such as excessive washing, checking, and counting.
Sufferers can be plagued by intrusive thoughts, ranging from unwanted sexual fantasies to committing violent acts.
OCD is treatable although the cause is not fully understood.
SSRIs (Selective serotonin reuptake inhibitors) such as fluoxetine (Prozac) or the tricyclic antidepressant clomipramine are commonly prescribed and can be highly effective - 60% of patients on medication improve.
The response rate can be higher when combined with cognitive behavioural therapy.
This is a type of psychotherapy that focuses on solving the patient's present problems, and is recommended as the first line treatment for people with mild OCD.
But half of patients relapse when drugs are withdrawn and a quarter do not respond to conventional therapies at all.
Even when medication is effective, a 30-50% reduction in symptoms is the best that can be achieved.
And if the therapy and drugs don't work, invasive brain surgery is the only remaining option.
The need for more treatment options and anecdotal reports of OCD patients undergoing periods of remission after using hallucinogens led Moreno and colleagues to give psilocybin to nine people who had had not responded to other treatments.
The patients did see a significant reduction in symptoms for up to 24 hours after they were given psilocybin even on the lowest dose.
But because there was no group given a different drug or no drug at all to compare them to, the benefits could have been simply due to care and attention from the researchers.
The way that psilocybin works means that it can have severe mind-altering effects.
In this study, the people taking the drug rated the hallucinogenic experience as "stressful" at some times but "psychologically and spiritually uplifting" - describing encounters with past lives, faraway planets, and communing with deities.
But all had previously taken psychedelic drugs before the study - which the researchers say was to increase the safety of the study.
However Dr Paul Blenkiron, a consultant in adult psychiatry at Bootham Park Hospital, York, said: "I'm concerned that the study only measured effects up to 24 hours and OCD is a chronic condition, not measurable in hours and days, but months and years.
"About 12% of people can suffer flashbacks after less than 10 exposures [to psychedelics] many years later, beyond the six months of this study, so long term effects should be carefully assessed."
However, he added: "If this substance was effective and had fewer side effects in severe treatment-resistant case, it would be an option."
Experts also question whether the results are really valid.
"You would expect a spontaneous remission rate of 10% within in a year," said Professor Paul Salkovskis, Maudsley Hospital Centre for Anxiety Disorders, who asks whether it is safe to give people with OCD psychoactive substances at all.
"I'm very concerned that people with obsessional problems who experience bursts of nasty images, like sexually abusing their own child or stabbing someone, are being given a drug known to produce intrusive mental phenomena."