What's wrong with him?

My brother (19) says he's depressed, he cuts himself sometimes (superficial cuts)

My parents and I are supportive, they paid for his therapy sessions, we are a close family, everything at home is calm, we are not lacking anything.

But I'm mad at him, I'm not saying he doesn't feel bad sometimes, but he's being useless at home and only seems depressed when he has to do chores. He's always ready and looking nice when going out with friends, he goes to the gym often, he eats super well, he cracks his ass off laughing when gaming online, he goes to college (and his doing fine in college).

I'm sick of this, I clean the whole house by myself which isn't an easy job to do alone, I even clean the stupid bathroom I never use, I clean all this alone because he "is too sad, too depressed" but then at night he gets ready, with his hair done, his cool guy outfit, cologne and leaves the house with his friends. What's wrong with him? Is there something really going on? I went through depression a few years ago and this doesn't look anything like how I was, I barely ate, people basically had to force me out of the house to hang out, I had a real hard time, but this he's doing just doesn't makes sense to me.

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2 mo
Edit: I kinda want to slap him on the face, would that be a bad idea?
What's wrong with him?
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