Can you get mentally ill from living with a mentally ill person?

Well according to a psychiatrist I spoke with personally a while back it is possible to have a 'mass psychosis' where two or more people experience the same symptoms as each other. I personally think this is rubbish and was the only way they could explain away something they did not understand. And you can become mentally unwell living with or without mentally ill people/persons. If you are personally attached to the person experiencing mental health issues it can be very taxing emotionally and mentally especially if you have no insight into what the person is experiencing. If you are concerned there are groups for the friends and family of people experiencing 'mental illness'