It's something that I've been told to pick up on, and I have during my term in psychiatry. My register mentor said that you could often diagnose someone based on your reaction after interviewing them. If you feel depressed after an interview, the person is probably depressed; if you feel racy and energetic, the person is manic; if you feel confused, the person is psychotic; if you feel annoyed, the person has borderline personality disorder. And although this seems very superficial- basing a diagnosis on how you feel- it works!
I've felt so low almost to the point of tears, after talking to a depressed patient.
I've felt confused, mystified (and somewhat cautious) when talking to a psychotic patient. (I asked him why he was in hospital, and he said, "Because I was going to kill John Howard. That's all. He greased my backside. Agents told him to...")
And although it's often stigmatised, mental illness is a biological illness. Well, mental illness is the combination of a biological fault, with an upbringing that doesn't teach you adequate coping strategies. And sometimes, genetic predisposition and life circumstance plays a part as well.
On a tangent, John and Josh drove to Adelaide from Sydney yesterday! And are enjoying the throbbing city life of this city. I'm much impressed- They drove from 5am to 9pm to make it here in a day. I took 2 days, and didn't want to drive for a week afterwards.