<human>: Condense the text into a few key points

Hi, this isn't really about me but about my close friend who I know and love like a brother. Shortly after his 18th birthday he began dating someone online, from Washington state (we're on the east coast). Previously he had been talking online with this girl before he turned 18, and I talked with her a few times and she seemed nice enough.

However, they're coming up on two years at this point and I'm really worried about him. Before they were dating we would always hang out and play football/watch television/play video games, typical friend stuff. But now he is completely at her beck and call, one text from her and he'll ditch everyone. Sometimes I don't see him for days at a time because he's waiting on her online.

I feel I should take a break to note that he has never met her in person. They FaceTime and text, but don't actually meet up.

But what I think is the worst is his mood. He's always had depression, I helped convince him to get help in the first place. But ever since he's started dating her his mood seems to be worse than usual. Worse than that, whenever he's feeling down she gets really weird, saying that he's not responding to her (due to the fact he's sleeping for 18 hours due to aforementioned depression) and she thinks he hates her now. She also has to point out how depressed SHE is whenever he tries to talk about his depression, and generally tries to make the conversation about her.

I'm really worried that he's in over his head here. She is the first person he's ever dated so I'm not sure if he knows what is ok or not in a relationship. But I'm also worried about saying anything, because I know she'll try to make me out to be the bad guy and have him cut all ties with me, which I don't want since he's like my little brother. Reddit, what should I do?
<bot>: My best friend since junior high is in an unhealthy long distance relationship, and I don't know how to help him.