Why won't my friend respond to Facebook messages?

[Jeff]

First, it is one of my best friends and isn't mad as far as I know. He has a history of talking with me or other friends and making plans for the following day then that day it is as if he dropped off the face of the earth, no response 'sorry turns out I can't make it' or anything like that. We had been frequently video chatting for a period but that stopped. I posted directly on his FB wall about video chatting again, and he even responded saying 'sure thing, I'll message you when I get off work tonight.' Sure enough no response at all that night or the following days. I messaged him asking if we could still video chat, and the chat box doesn't even show him as 'Seeing' the messages (e.g. Seen Mon 4:23pm) after weeks on end, which leads me to think he is actively avoiding reading messages. And yes, he has easy access to FB through smart phone and computer and has been online almost daily (I can see his Green Dot in the chat window, I've even messaged him then, and he still ignores it). What could be causing this? Depression? A funk?

[abraXus]

it sounds to me like he is just tired of talking to you... or is too busy doing other things