Scientists have carried out the first controlled medical experiment in 40 years with the hallucinogenic drug LSD which they used as part of a psychotherapy course to treat severe depression in terminally ill cancer patients.
Volunteers given high doses of LSD - which came to prominence in the hippy culture of the 1960s - showed a 20 per cent decline in their symptoms associated with the extreme anxiety of their medical condition, the researchers found.
The small pilot trial, which involved just 12 men and women, also showed that there were no severe side-effects of lysergic acid diethylamide, the psychoactive chemical commonly known as "acid".
However, their depressive symptoms did get worse when given only low doses of LSD, the scientists said.
"These results indicate that when administered safely in a methodologically rigorous medically supervised psychotherapeutic setting, LSD can reduce anxiety, suggesting that larger controlled studies are warranted," concluded the study published in the Journal of Nervous and Medical Disease.