The mad composer. Note after excruciating note dragged out on to manuscript paper, 2 stone in weight lost while composing his latest opera, bronchial infections from the cold, absinthe on a drip. Mumbling to himself, shouting at strangers, scribbling bar lines on restaurant napkins, sitting at a piano, freezing and alone in a garret with “it doesn’t have to be mad to work here but it helps” written on the wall. In his own shit.

It’s a cliche as erroneous as it is widespread and it is, forgive me, quite maddening and completely false.

The truth is that there is no more a link between star sign and intelligence than there is between madness and creativity. That a link has been drawn between the two is, however, under–standable. How else can we explain the outrageous creative power of a Mozart or a Beethoven without resorting to some kind of brain chemistry imbalance? If these guys were as normal as everyone else, then where is the magic? It is the sad way of the world that someone doing something extraordinary (Beethoven) has to have an extra dollop of extraordinary (bipolar disorder) to make it, well, even more extraordinary.

Creativity is a broad subject. Musical creativity is what I know about. It’s my job, my passion, my absolute reason for being. And let me tell you something categorically: the great composers were not mad. Disturbed, sure. Angry, broke, alcoholic, anxious, neurotic, syphilis-ridden, depressed, grieving – often. As are most of us for that matter (minus the syphilis). But with the singular exception of Schumann, whose fictional characters Florestan and Eusebius were invented by him to depict in music his bipolar mood swings, there is not one big-name composer who, by today’s standards, would be hospitalised, or likely even diagnosed, with one of the more severe mental illnesses.

Robert Schumann is the one big-name composer who, by today’s standards, would be hospitalised. Photograph: Lebrecht

And I think that qualification of severity is the point – we are all, to an extent, a little bit mad. We are all most definitely diagnosable. I have not met anyone who does not tick most of the boxes in at least one condition set out in the DSM-5 (the diagnostic manual for mental illness so beloved of psychiatrists around the world). Glance at Twitter, look at the NHS stats on obesity or alcohol-relate illnesses, open a newspaper. We are the emotionally walking wounded. We also know very little about the mind. Keats saw a psychiatrist who diagnosed him with a “mental illness related to poetry” and I’d love to think things have moved on, but my experience is that they haven’t. Not really. Medication has got better, diagnoses are slightly more accurate (and expanded), Jeremy Corbyn has introduced a new shadow cabinet post for mental health, stigma has been reduced. But I think that if we were really to understand just how little our doctors know about the workings of our mind as they prescribe yet more meds for us, we’d be absolutely terrified. I’ve been diagnosed with at least seven different mental conditions over the past 10 years and it scares me that, simply put, all or none of them could be true.

When it’s 4am and the wolves are at the door, then being able pour out notes on to the manuscript paper is the way out

When it comes to being creative, my mental health is irrelevant. But when it comes to my mental health, creativity becomes very relevant. It seems to me vitally important to communicate the message that these composers achieved so much not because of, but despite, being anxious, neurotic and socially awkward.

Creativity is, for me, a sign of mental wellness and not one of mental illness. Because when it’s 4am and the wolves are at the door – when the solution is either suicide or homicide, and the twitching, itching, head gremlins are out in force – then being able to sit at a piano, and pour out notes on to the manuscript paper is the way out. Or so I keep telling myself because, going over piano pieces in my head, checking memory, trying out new interpretations and playing through entire concert programmes is more often than not the only thing that stops me throwing myself out of the window. Music helps my own particular brand of madness. It’s the only medicine that has never let me down.

Consider Bach, whose Chaconne for solo violin (from the Partita No 2) is a piece that almost literally kept me alive for years. He was orphaned by the age of 10, lost most of his siblings, was abused at school, was shipped off to live with his brother who despised him and treated him accordingly, walked hundreds of kilometres as a teenager to go to the best music school he knew of, had 20 children, as many as 11 of whom died in infancy or childbirth, and lost the great love of his life, quite suddenly, when he was away for a weekend on business. He could have lost his mind, but he didn’t. Yes, he was a little bit wonky, displayed a few OCD traits and had a temper. But he also wrote endless music for the church and court, taught composition, the organ and the harpsichord, conducted the choir, wrote for himself and other patrons and played the organ during church services and generally went all Red Bull in the work arena. Without music, he would, I am convinced, have gone quite, quite mad and likely eaten the Baroque gun. He didn’t need to read about what study after study tells us today – that creativity is inherently a good thing and has a proven positive impact on everything from self-esteem to discipline to focus to physical and mental health, literacy, numeracy and social skills. He just knew.

As a society we are constantly looking outside of ourselves to fix what’s wrong with us. We buy things we don’t need, pursue relationships to fill the hole, get stoned, live in the gym, travel to far-flung places. The extraordinary gift that creativity offers is that it goes the other way and journeys inside of us. We can enter “the zone”, we lose track of time, feel totally present in the moment and achieve all of the benefits that that awful buzzword “mindfulness”promises (relax, next month it’ll be polenta or ballet-yoga). One of the saddest myths about creativity is that it somehow belongs only to a certain section of society; that only if you work in the arts or totally immerse yourself in artistic pursuits can you lay claim to the word “creative”. We all are born creative. Picasso said that all children are artists. He added that the problem is how to remain an artist once they grow up.

Every century has its challenges, and we are facing some terrifying, immense ones. Creativity is the act of turning new and imaginative ideas into reality. It is an ability to perceive the world in new ways. It involves two processes: thinking, then acting . And boy do we need to act. Being creative can start with small acts. Learning the piano alongside your kids. Writing down a few words a day. Taking a photography class. Learning to cook. Painting, drawing, baking, gardening, dancing, knitting, singing, anything that counterbalances the 9-5 side of the brain. And if I am wrong and creativity and madness are indeed intertwined, then it has still got to be better than working for a hedge fund, trawling through Facebook instead of reading to the kids, staring glassy-eyed at reality TV and pretending everything is just fine.

• Intrumental by James Rhodes (Canongate, £16.99). To order a copy for £12.99, go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min. p&p of £1.99.

• James Rhodes will be appearing on Radio 3’s In Tune on 25 September as part of Radio 3 and Wellcome Collection’s Why Music? weekend. He is on tour from October and his memoir, Instrumental, is published by Canongate.