Would you ever help an ex-boyfriend out?

My ex bf didn't do that much drugs when we were going out. But one night he was out of control and He hit me and pushed me down the stairs. The neighbors called the police. He was arrested. Its been like a 2 yrs since then. I have a restraining order on him. A mutual friend of ours I haven't seen since then I talked to him the other day. He said my ex started doing heroin heavily since we broke up and that he talks about me a lot. As much as I hate him I don't want him to harm himself. Should I call him ? I'm over him completely but it hurts to see some one you loved destroy themselves. I don't know what to do.