I have a friend who goes through this periodically. She ignores my calls and emails so I quit trying. Months will pass. She then calls me and we schedule a time to get together and at that time she usually tells me she was in a depressed state and needed to be alone. I guess I get it so it's easy for me to understand. The first few times it was a bit weird, I feared she was brushing me off. Now I wait for the cycle to come full circle and I'm here for her when she's ready, unless I'm in a funk and not ready.