According to new research, up to two-thirds of major writers, poets, musicians and painters, are hyper-manic or manic depressives. Psychologists say that it is the mania of sufferers which drives their creativity into unusual and unique directions, giving their work the mark of genius.
But modern drugs, which damp down moods and feelings, may well interfere with the process of creativity, and some patients stop taking them because they do not want to lose their talent.
Research by a team at the University of California looked at 20 top European writers, poets and artists, and found that 70 per cent had hyper- manic symptoms, 14 times the rate in the general population. More than half had a manic depressive illness, 10 times the normal rate.
Another study of 36 British poets born between 1705 and 1805 and carried out by professor Kay Redfield Jamison of John Hopkins University, found that the poets were 30 times more likely to have a manic depressive illness than the general population. They were also 20 times more likely to be committed to an asylum.
Writing on the use of drugs, Professor Redfield says, "These drugs can dampen a person's general intellect and limit his or her emotional and perceptual range. For this reason many manic depressive patients stop taking these medications."
There are, however, even bigger ethical problems looming with the eventual identification of the genes predisposing people to mental illnesses.
Dr Gordon Claridge, lecturer in psychology at Oxford University, Fellow of Magdalen College, and author, said: "I believe there is a link between some forms of mental illness and creativity. A high proportion of highly creative people do suffer from these conditions.
"People who take drugs who are creative do complain that their creativity is taken away and sometimes they come off them for that reason ... There is no doubt that drugs have an effect, but the big ethical question is, if you find the genes and make the corrections, will you in effect be removing genius?"