Talking on the phone to my brother...need advice please.

Hi,

My brother is 20 years old (2 years younger than me) and studying computing at university. He has always been really into computers and spends a lot of time playing games, even sleeeping on the armchair next to the computer when he's home. 

He has been diagnosed with aspergers and I think with depression, it's been a few years now since I first heard about this. I don't actually know for sure becuase its never really been talked about properly. I think in some ways I didn't want to listen, and in other ways I was never really told, it was assumed that I just knew and was mentioned in passing when my parents were speaking to other people. 

My brother is a very quiet and private person. I don't think he would want me to talk about it with him. I don't think he would want me to talk about it with others either, so I haven't. But it's left me feleing a little bit like I don't really know what to do, and don't really have anyone to talk about it with.

I find it really hard to communicate with him. He doesn't really talk, he will usualy reply with one word answers. He is better in person, but on the phone if I stop talking, there is just silence until I start rabbiting on again, and asking lots of questions which get one word answers. When he speaks it's very quiet, so I sometimes don't hear what he says. It feels a bit like he just can't be bothered to talk  and just wants the call to end. I don't call him very often, I send some texts but he often doesn't reply. 

At uni he lives with a group of guys he doesn't really know. I imagine that he is very quiet in the house, and doesn't really talk to any of them. He says they're all nice people which is good. He sometimes burns food, or forgets to lock the door so has been in a bit of trouble with the landlord before. I don't know for sure, but I imagine that he doesn't really interact with anyone at university, but does talk to people online. I know he's had problems where he hasn't been able to do group work, so he's been given alternative work where he doesnt have to work in a group.

He had, and possibly still has, a bit of a problem with drinking too much alcohol. When he gets drunk he is very chatty and even hugged me once. So it's not that he has nothing to say, there just must be something esle there holding him back.

While I was at uni I didn't really try very hard to keep in touch with him. After I've left, I've gone down to see him. He got on well with my ex-boyfriend so they spoke quite a lot and it wasn't too awkward. But the couple of days that I did spend alone with him, I didn't really feel like he enjoyed and I felt like I was forcing him to do what I wanted to do. He can be quite passive and never really suggests anything he wants to do, even when asked, so we always ended up doing what I suggested.

I want to be a good sister, and to talk to him, find out what he's up to, what he enjoys, how he's feeling, but I'm finding this impossible right now. I don't know if it's something I'm doing wrong, whether I could behave differently. I'd like to understand what's going on in his head.

Could anyone give me some advice on what I could do differently? Perhaps I should try communicating with him online? Has anyone else been in this situation before/now? How should I act? What's going on in his head?

Thank you for taking the time to read this, I really appreciate it. And thank you in advance for any comments you have. Please be honest with me.