This is a question I keep coming back to: Why do some people consider mental illness fair game for all the lame, insensitive jokes?

Why do people offer their comfort to their friends going through treatments for other diseases but shun their friends with mental illness? My own observation would even suggest to me that people with mental illness are avoided by others because they are almost afraid to be around someone with a mental illness. I don't really understand the feeling because I want to reach out to my friends who have mental illness, to comfort them and tell them that eventually everything will be okay. How can someone with a mental illness heal on drugs alone? They need the love and comfort of understanding people as well.
Just as we comfort a friend with cancer, or MS and any other disease, let's also recognize that we need to do that with people who have mental illness as well.