Question: What do you do when depression causes you to lose interest in everything?

I'm not feeling terribly down right now, but I know depression is hitting again because I just can't "get into" anything. I'm a big gamer but all the games feel hollow and boring right now. I skip from one to another in quick succession because I don't feel like I'm enjoying it. I've also tried reading, watching TV and even cooking (yeah I typically enjoy it) but nothing "clicks" for me.

I hate this part of this illness because it makes my days feel so empty... I want to sit around and not do anything. Or just sleep 24/7 because at least my dreams can be interesting... when they're not being terrifying, at least.