Genius cannot exist without mental disorder, according to a study that names George Orwell, LS Lowry and Lewis Carroll among 21 artists who suffered a form of autism.

　　The psychiatric portrait of some of the most imaginative minds in history claims to prove the link between madness and greatness.

　　Beethoven, Mozart, Hans Christian Andersen and Immanuel Kant are among the musicians, writers, painters and philosophers who have been diagnosed with Asperger's syndrome.

　　Prof Michael Fitzgerald, a psychiatrist and expert in the syndrome that affects social relationships but not intellect, claims that people with Asperger's can have exceptional artistic creativity, as well as mathematical genius.

　　Einstein and other engineering geniuses have already been suggested as sufferers. Prof Fitzgerald claims that some of the same genes that cause Asperger's are a source of creative brilliance.

　　One of the characteristics of Asperger's is thought to be an inability to engage in creative play. But Prof Fitzgerald says the syndrome almost certainly drove Orwell, Lowry and Carroll to writing and painting as a form of "self-help".

　　"Asperger's and creativity are two sides of the same coin - you can't get one without the other," he said.

　　His claims are set out in The Genesis of Artistic Creativity, which is to be published later this month, and have already won support from The National Autistic Society.

　　Dr Judith Gould, the director of the diagnostic unit at the National Autistic Society, said yesterday: "The theory makes sense, because one of the diagnostic criteria for Asperger's is a 'patchy' ability, where some skills are better than others.

　　"That is greatly emphasised in geniuses."

　　However, Prof John Geake, a researcher into cognitive creativity attached to Oxford University and Oxford Brookes University, was not convinced.

　　He said: "The truth is that most highly intelligent people are very competent at life." Prof Fitzgerald, a psychiatrist at Trinity College, Dublin, has diagnosed more than 900 people with the syndrome since he began practising in 1974. For the study, he assessed the personalities of 21 geniuses against the criteria for Asperger's, using biographies and first-person recollections. He believes that Orwell displayed the social impairment, narrow focus, repetitive behaviour and clumsiness typical of the syndrome. And Beethoven, who was "clumsy", "emotionally immature" and "had an unusually large head" also fit the criteria for Asperger's. An expert on Beethoven, Dr Barry Cooper, said last night that he barely recognised the description of the composer.