<human>: Can you provide a brief overview of the text?

When he was about 15-16 years old my brother smoked a lot, but managed to quit after that. He started again two years ago and although he says he wants to stop, he doesn't seem to be making an effort.

He's had a few months of free time while waiting for school to start, and during this time his relationship with the rest of my family has been getting worse. He spends his whole day gaming at home, until 5am or something, goes to sleep and doesn't wake up till 1pm. Same thing happens everyday and my parents have given up on trying to convince him to change. 

This morning, he didn't go to church (and this is rare for my family, we go practically every Sunday morning). When I came home, he had just woken up. While I was having my lunch he walked over to the table, grabbed his computer and went into his room and locked the door. I smell smoke in the house and I have no idea what else he is doing. My oldest brother [22M] just called a few minutes ago and wanted to talk to him, but when I called he refused to respond.

After putting down the phone, I called him and knocked on his door and he responded sounding really frustrated or agitated, I don't know, and said "NO." when I said my oldest brother wanted to talk to him. He then told me to "Go away" and that has never happened before. I'm usually quite close to him and I just don't know how to respond.

I don't know what it is that's changing him and making him this way. Over the last few months he has become more purposeless and is really rude to my parents, shouting at them and all. I don't know how they put up with it when I'm already having difficulties doing that.

Has anyone faced similar situations? It's probably seems like quite a minor thing but I love my brother and I want to do what I can to help him.
<bot>: My brother's relationship with the rest of the family is deteriorating and he is picking up bad habits that he refuses to drop. What can I do to help him?