One ingredient in this volatile mix is youthful misery. Many literary greats lost a parent in childhood (Swift, Keats, the Brontes, Hawthorne, Virginia Woolf, Sylvia Plath), were orphans (Poe, Tolstoy, Conrad) or were plunged into poverty (Shakespeare, Melville, Dickens, Yeats, Joyce).
An unhappy childhood may help to develop the power of fantasy and imagination. It also raises the risk for mood disorders in adulthood, which have a robust association with literary creativity. Writers have a high prevalence of depression and bipolar disorder.
Some writers also have difficulties with social adjustment, ranging from mild introversion to social anxiety disorder or Asperger's syndrome.
They may have turned to literature after being frustrated in their attempts to relate to people in more conventional ways. Others become physically ill, either from dubious lifestyle choices, bad luck or physical hardship. In Orwell's Cough, they explore few writers and their psychological and physical maladies. - Daily Express
The only medical fact known about Shakespeare with certainty is that his final signatures show a marked tremor. Compared with other Elizabethan writers, Shakespeare had an unhealthy obsession with syphilis. DH Lawrence wrote: "I am convinced that some of Shakespeare's horror and despair in his tragedies, arose from the shock of his consciousness of syphilis."
An obscure satire called Willobie His Avisa seems to suggest that Shakespeare was part of a love triangle. This seems to mirror the situation in the Sonnets.
The standard Elizabethan treatment for syphilis was mercury. As the saying goes, "A night with Venus, a lifetime with Mercury". Mercury had alarming side effects. It caused rotten teeth, bad breath and drooling. Mercury also causes tremor and personality changes such as social withdrawal and timidity.
THE BRONTE SISTERS
All six of the Bronte siblings died of tuberculosis, a Victorian plague that killed off one per cent of the English population per year. TB entered the Bronte household after the older girls were infected at the Clergy Daughters' School.
This was the place made infamous by Charlotte as the brutal Lowood School in Jane Eyre, where the girls were beaten, starved and terrorised with tales of hellfire and damnation.
Although the consumptive artist is a tired cliché, there may be some truth in it. The immune system is weakened by emotional turmoil, of which the Brontes had plenty.
Charlotte, Emily and Anne had depressive episodes; brother Branwell had bipolar disorder and dipsomania; Emily, friendless, brainy and strange, probably also had Asperger's syndrome and social anxiety disorder.
In 1904 Joyce had glee or gonorrhoea. His "frenemy", Dr Oliver Gogarty, directed him to a local specialist in such matters, who would have given Joyce state-of-the-art therapy: a purple solution of potassium permanganate.
Soon he developed terrible attacks of eye pain and arthritis. This may have been an auto-immune illness triggered by chlamydia. Joyce suffered through 11 gruelling eye surgeries. Not surprisingly, he developed a terror of scalpels.
WILLIAM BUTLER YEATS
On Christmas Eve 1929, the poet Yeats was delirious and suffering from a 104F fever in the Italian resort town of Rapallo. His crackpot buddy Ezra Pound fled the scene, fearing contagion. One of Mussolini's top doctors was called in and made the exotic diagnosis of brucellosis.
Yeats recovered after weeks of fevers and drenching sweats, thanks to shots of arsenic and horse serum. But his brush with mortality did not leave him unscathed.
The brilliant and peculiar poet, who may have had Asperger's syndrome, became obsessed with death. This is reflected in his masterful final poems. Gossips called him the "gland old man" and "a Cadillac engine in a Ford car".
Swift was a walking textbook of pathology. He suffered from an inner ear condition that led to horrible vertigo and tinnitus, which he described as "a hundred oceans rolling in my ears". His obsessive-compulsive disorder ruined his love life. James Joyce said that "he made a mess of two women's lives".
These were Stella Johnson, who may have been his secret wife in an unconsummated marriage, and the heiress Vanessa Vanhomrigh, who had a mad, futile passion for Swift. Swift had his most productive decade in his 50s when he wrote Gulliver's Travels and a great deal of smutty poetry.
Swift's subsequent behaviour was increasingly bizarre. He may have had frontotemporal dementia, which in its early stages may be associated with increased creativity from loss of inhibitions.
Milton went blind in middle age, which he attributed to his propaganda work for Oliver Cromwell. However, the more likely culprit was retinal detachment from severe myopia. Milton ruined his eyesight in childhood by staying up into the wee hours reading the Greek and Latin classics.
He is known to have "dabbled in physic", or taken popular medicines of the day in a failed attempt to save his eyes. These may have included "mummy", human sweat, human placenta, cat ointment, oil of puppies and sugar of lead.