Until recently, prescribing Ecstasy, mescaline or magic mushrooms has been a guaranteed way for a psychiatrist to lose his research funding, his job or even his liberty. But now, scientists are beginning to suspect that such illegal drugs may be the key to treating a range of intractable illnesses, from post-traumatic stress disorder to depression. These chemicals [include] the psychedelic drugs psilocybin, derived from magic mushrooms, and LSD, as well as Ecstasy. A series of studies performed in Britain and the US is beginning to tease out their potential benefits. People become very emotionally tender on Ecstasy, which makes you more responsive to psychotherapy," explains Dr Robin Carhart-Harris. [In] volunteers given the ... drug, the area of their brain involved in positive memories became more active, while another processing negative memories was damped down. "We think this would make it easier for patients to revisit a traumatic memory and overwrite or control it," says Carhart-Harris. Earlier studies have made surprising discoveries about what psilocybin, a class-A drug in Britain, was doing in the brain. These in turn could lead to new treatments for depression and agonising cluster headaches. This may all sound radical, or even dangerous - yet half a century ago, research into the effects of psychedelic drugs was widespread and respectable. More than 1,000 papers were published looking at ways that psychiatrists could help patients with hallucinogenic chemicals.