First test of "psychedelic psychotherapy" since the 70's. Researchers hope effects will improve quality of life.

    Scientists are exploring the use of psychedelic drugs such as LSD to treat a range of ailments from depression to cluster headaches and obsessive compulsive disorder.

    The first clinical trial using LSD since the 1970s began in Switzerland in June. It aims to use "psychedelic psychotherapy" to help patients with terminal illnesses come to terms with their imminent mortality and so improve their quality of life.

    Another psychedelic substance, psilocybin - the active ingredient in magic mushrooms, has shown promising results in trials for treating symptoms of terminal cancer patients. And researchers are using MDMA (ecstasy) as an experimental treatment for post-traumatic stress disorder.

    In the Swiss trial eight subjects will receive a dose of 200 microgrammes of LSD. This is enough to induce a powerful psychedelic experience and is comparable to what would be found in an "acid tab" bought from a street drug dealer. A further four subjects will receive a dose of 20 microgrammes. Every participant will know they have received some LSD, but neither the subjects nor the researchers observing them will know for certain who received the full dose. During the course of therapy researchers will assess the patients' anxiety levels, quality of life and pain levels.

    Before hallucinogenic drugs became popular with the counter culture, they were at the forefront of brain science. They were used to help scientists understand the nature of consciousness and how the brain works and as treatments for a range of conditions including alcohol dependence.

    Charles Grob, a professor of psychiatry at the Harbor-UCLA Medical Centre, is in the vanguard of the resurgence of scientific interest in psychedelics, having recently completed a trial that used psilocybin to help patients with terminal cancer come to terms with their illness. "I think there's a perception these compounds hold untapped potential to help us understand the human mind," he said.

    The way hallucinogens such as LSD (lysergic acid diethylamide), psilocybin and mescaline (the active ingredient in the peyote cactus) act on the brain is reasonably well understood by scientists. The drugs stick to chemical receptors on nerve cells that normally bind the neurotransmitter serotonin, which affects a broad range of brain activities. But how this leads to the profoundly altered states of consciousness, perception and mood that typically accompany a "trip" is not known.

    Prof Roland Griffiths at the Johns Hopkins School of Medicine in Baltimore Maryland recently published a study of 36 healthy volunteers who were given psilocybin and then observed in the lab. The participants' ages ranged from 24 to 64 and none had taken hallucinogens before. When the group were interviewed again 14 months later 58% said they rated the experience as being among the five most personally meaningful of their lives, 67% said it was in their top five spiritual experiences, and 64% said it had increased their well-being or life satisfaction.

    "The working hypothesis is that if psilocybin or LSD can occasion these experiences of great personal meaning and spiritual significance ... then it would allow [patients with terminal illnesses] hopefully to face their own demise completely differently - to restructure some of the psychological angst that so often occurs concurrently with severe disease," said Griffiths. So by expanding their consciousness during a session on the drug, the patient is able to comprehend their thoughts and feelings from a new perspective. This can lead to a release of negative emotions that leaves them in a much more positive state of mind.

    Twelve patients with terminal cancer have already helped Grob to test this idea and, although the research is not yet published, anecdotal reports from some subjects are encouraging. Pamela Sakuda (see below) was diagnosed with stage 4 colorectal cancer in December 2002. Her husband, Norbert Litzinger, said the psilocybin treatment transformed her outlook.

    "Pamela had lost hope. She wasn't able to make plans for the future. She wasn't able to engage the day as if she had a future left," he said. Her "epiphany" during the treatment was the realisation that her fear about the disease was destroying the remaining time she had left, he said.

    Despite fears that psychedelic drugs can induce psychosis, they are comparatively safe when administered with the proper precautions and with trained medical professionals present, according to a manual for studying their effects, which was recently published in the Journal of Psychopharmacology.

    They do have a powerful effect on a person's perception and consciousness and cannot be considered "safe", but they are almost entirely nontoxic, they virtually never lead to addiction and they only rarely lead to long-lasting psychosis (usually in people with a family history of mental illness). The main danger is that the person taking the drug injures him or herself while in a mind-altered state, for example because they think they can fly. The manual states, for example, that, "investigators need to be confident that the volunteer could not exit the window if in a delusional state". Griffiths does not advocate recreational use.

    Since the 1970s, scientific research into the effects hallucinogenic drugs have on the brain and their potential benefits has become a pariah field for any scientist who wanted to keep their reputation - and funding - intact. The psychologist Timothy Leary was the most famous advocate of the scientific and recreational use of psychedelic drugs. He conducted experiments at Harvard that were widely criticised and he was accused of faking data.

    "The way I view it is we experienced some kind of broad cultural trauma back in the 60s and these drugs became demonised in that context," said Griffiths. "As a culture we just decided clinical research shouldn't be done with this class of compounds," he said. "This was partly the federal regulatory authorities, it was partly the funding agencies and it was partly the academics themselves ... Leary had so discredited a scientific approach to studying these compounds that anyone who expressed an interest in doing so was automatically discredited."

    Dr Rick Doblin is president of the Multidisciplinary Association for Psychedelic Studies (MAPS) in California, a nonprofit organisation which funds clinical studies into psychedelic drugs, including the Swiss LSD trial. "These drugs, these experiences are not for the mystic who wants to sit on the mountain top and meditate. They are not for the counter-culture rebel. They are for everybody," he said.

    Case Study: Edited extract from an interview Pamela Sakuda did for researchers on the psilocybin experience.

    "As the session began, and as it built up, I felt this lump of emotions welling up and firming up almost like an entity. I started to cry a little. Then it started to dissipate and I started to look at it differently and I think that is the beauty of being able to expand your consciousness. I don't think the drug is the cause of these things. I think it is a catalyst that allows you to release your own thoughts and feelings from some place that you have bound them to very tightly. I began to realise that all of this negative fear and the guilt was such a hindrance to making the most of and enjoying the healthy time that I'm having - however long it may be. I was not utilising it to the best and enjoying my life because I was so afraid of what wasn't there yet. These substances occur in our natural world and people have been using them for thousands of years to treat physical illness, to treat social and behavioural problems."