Could Ecstasy, LSD and magic mushrooms one day be legitimate prescription medicines? It sounds unlikely, but doctors and researchers in the US and across Europe believe it is possible and that new science will prove the case.

Second chances are rare in science. In the Fifties and Sixties, hallucinogenic drugs, such as LSD, were hailed as the magic bullet to everything from alcoholism to migraine. But they became caught in the crossfire of the cultural wars of the times. Western politicians banned the use of psychedelics in research once they started to be used recreationally, and became associated with flower-power and the counter culture. The drugs were dangerous; the science was flawed; the researchers biased.

But a comeback has been under way for more than a decade. A new generation of researchers say that psychedelic drugs can treat conditions such as addiction, anxiety, post-traumatic stress disorder and a type of headache called cluster headache.