WORLD Bipolar Day will be celebrated this week on March 30, the date on which Vincent Van Gogh was born in 1853. There has been much debate about the nature of Van Gogh’s mental illness, but it’s fairly likely that he suffered from bipolar disorder, which may have broken out into florid episodes of psychosis (manifest in the "ear-cutting" incident a year before his suicide in 1890).

That he suffered in his creativity is certain and is well documented in the manic proliferation of letters to his brother, Theo. Much less certain is whether there was a cause and effect relationship between Van Gogh’s mental illness and his creativity. Was he a genius because of it, or in spite of it?

The links between genius, creativity and mental illness – especially mood disorders such as depression and anxiety – have been the subject of myth, fascination and inquiry since classical times. Aristotle kicked off the debate when he said: “No excellent soul is exempt from a mixture of madness.”

For centuries, philosophers and scientists have tried to unpick the complex relationship between the two. It is known that writers suffer much higher levels of depression than are present in the general population (Tolstoy, Plath, Woolf, Foster Wallace to name but a few), but we still don’t really understand how and why this influenced their writing. What we do know is that the notion of the tortured poet or mad artist is both compelling and deeply embedded in our cultural psyche.

Why is our imagination more aroused by Van Gogh’s "ear", than by Monet’s gentler, less manic, "water lily" personality? And why is it that we cast golden calves and superheroes out of the artists and writers who, as a result of mental illness, have behaved in ways that would land us more ordinary souls with nothing short of an Asbo?

If Van Gogh had been a plasterer or plumber, it’s probably safe to say that not a single thesis would have been written about the quality of his plastering on the days when he was manic (or the total absence of it on the days when he was depressed). Creative genius thinks and feels outside of the box, performs synaptic acrobatics, lures and coerces us to levels of consciousness and experience that we didn't know were possible. As the reader, the viewer, we can go there sanely, safely, with nothing more tortured than a bout of armchair suffering. The artist takes all the risks and then offers up the hard-won fruits of their labour. For this, we pay homage and even glamorise their suffering in depression, anxiety, or, worst of all, full-blown psychosis.

There are various theories on the links between creativity and torment. Mental illness and creativity are both rooted in the unconscious mind whose operating system pays no heed to convention or conformity (just think of your last weird dream). The unconscious is capable of making connections, meanings and symbols that are novel and unique. In this sense, the unconscious mind is powerfully innovative and a profound source of knowledge. But it is also scary because there are no limits, no inhibitions and no routines.

As humans, we need boundaries and structure in the general run of our day to day lives. Without these, we are vulnerable to internal chaos where thoughts and feelings can run amok, take us hostage and lead us to the brink of insanity and beyond. Yet it is these same Groundhog Day rituals that constrict and stifle our imagination, atrophying the creative muscles that mobilise us to think and feel outside of the box – the key ingredient of great art and original thinking.

Perhaps one of the reasons why we hold artists in such high regard is that deep down, we admire their courage and determination to go to the brink and beyond, see some of what is out there and then report back (through their canvas, their words, their music). This requires not only boldness and fearlessness, but organisation and pragmatism. Perhaps the real genius of the artist lies in their capacity to straddle these two opposing universes without disappearing down the treacherous crevices in between.

The serious and committed artist is willing to stumble blind into the dark abyss in the hope that they will hit upon something new, never seen, thought or crafted before. It seems to me this is more about being brave, not mad.