Janice Galloway, 58, the author of titles such as The Trick is to Keep Breathing, Foreign Parts and Blood, was accused of using Graeme McNaught's medical issues in her novels.
Concert pianist McNaught, 54, of Mount Vernon, Glasgow, is on trial at Hamilton Sheriff Court and faces a total of 10 charges of placing Miss Galloway in a state of fear and alarm. He has denied all the claims against him.
Miss Galloway, of Uddingston, Lanarkshire, was yesterday questioned by defence lawyer Desmond Ziolo who said McNaught believed his character had been used in books including the 2002 novel, Clara, in which the main character's husband has a mental illness. She said: "It wasn't the first time I had heard this from him. He got very upset because he assumed a story was about him. The books are not about mental illnesses."
Miss Galloway said her experiences with McNaught, who she said had threatened legal action, had shaken her confidence and left her struggling to write books.
The trial before Sheriff Ray Small continues.