I concur. I don't enjoy instant messaging because it implies I will always be 'there' - in a head-space to chat. I will take time to go into a chatroom and conduct multiple conversations, but I have enough trouble answering a phone call if I'm writitng, say, an essay - having to stop everything for a banal message is just odd.

On the other hand my SO has ADD, so he manages just fine - in fact, he tends to spend his study time with an electronic mock exam open, two webcomics behind this, Cartoon Network playing and possibly music, and he will IM and try to hold a conversation with me at the same time!