That's not to say you have to speak slowly, but think of it this way -- you're aiming to speak more like Brian Williams on the Nightly News then you are like yourself when chatting with your long-lost sister.
Your doctor will ask about whether you've been feeling down or blue, whether you've lost interest in things you usually enjoy, whether you feel guilty or especially down on yourself, whether your sleep and appetite are disturbed, whether you feel exhausted most of the time, whether you are having trouble concentrating and whether things have gotten bad enough that you've thought some about ending your life.