Years ago at a workshop I went to, Jo Shapcott said that she thought poets were prone to hypochondria and didn't like driving. These observations made sense to me at the time, connecting up. A few little, random symptoms might ingeniously be connected by a writer's imagination. Some little object seen out of the corner of one's eye while driving might make one's concentration drift while approaching red lights. In "The Information" Martin Amis writes "Poets don't drive. Never trust a poet who can drive. Never trust a poet at the wheel. If he can drive, distrust the poems ...".
But it's not all bad news. In "Tormented Hope" Brian Dillon suggests a link between "health anxiety" and creativity, pointing out that the illness can be used as an excuse to get a bit of piece and quiet. Charlotte Brontë and Proust were worriers. Fear can be a spur. Someone I know is thinking of using his worries to make him send some of his work off "before it's too late". I think Antony Burgess started frenzied writing when he death-threatened himself.