Drugs derived from magic mushrooms could help treat people with severe depression. Scientists believe the chemical psilocybin, the psychedelic ingredient in magic mushrooms, can turn down parts of the brain that are overactive in severely depressive patients. The drug appears to stop patients dwelling on themselves and their own perceived inadequacies.

However, a bid by British scientists to carry out trials of psilocybin on patients in order to assess its full medical potential has been blocked by red tape relating to Britain's strict drugs laws. Professor David Nutt, professor of neuropsychopharmacology at Imperial College London, will tell a conference today that because magic mushrooms are rated as a class-A drug, their active chemical ingredient cannot be manufactured unless a special licence is granted.