Tips about my friend and i?

My friend and I have been friends for most my life. However there are times when he would stop communicating with me for months to maybe even a year at times. I have nearly cut back the messages and phone calls I have sent I am since this recent shut down he has towards me( I don't strongly believe the shut is just at me but with everyone). I know he has a lot emotional pain so I trying not take is personally but its hard not to do.I do not want get too deep about the emotional pain he has just that does have a lot of it. I am trying to moved on with my life. Any tips when he finally does get out of being reclusive in his own world. I honestly do not want what will happen when he finally talks to me. In the past he usually acts like everything is fine. He and I met when we were 12 and 10 now we are 23 and 21.