We recently saw what happened - and I won't mention the act or this very smart guy's name - when people push other people... sometimes what you say is the straw that breaks the camel's back. Do you really want to live with that?
Edit: Most people who are depressed have no idea they actually are - so it's difficult to come to a realization that "I am depressed" unless you hit rock bottom with how you are manifesting said depression in reality. Usually it takes the constant nagging of a loved one for you to do something, someone who is close to the person and knows him or her well - would be best able to observe their mood changes and the impact this has on their life. Then the hard part comes - having the person deal with the situation.... and you tell me if asking for help has ever been easy for anyone, particularly intelligent people who think they can boil the ocean by their own self .