“I do know that at least 20 per cent of the parliament are taking some sort of antidepressant medication,” he said. “I don’t know who they are, but I know they are. I certainly think for people who are under a lot of stress, like politicians or senior ministers, a lot thrive on that. But others who get a lot of stress, well that can cause a depressive condition.”

Mr Robb made the comments at the South Australian Press Club, where he spoke and answered questions about the challenges of managing depression and life in the Liberal Party.