What could be wrong with my brother?

[Jocubus]

My parents are getting pretty concerned about my younger brother's behavior. To start he's 19 years old. Now the problem has been developing over the last year or so but it seems to be getting worse now.

He's completely shutting himself off from everyone. After he graduated highschool he stopped hanging out with any of his friends (the reason he gave is that they all like to drink and do drugs and he doesn't want any part of that). Within the last year the only time he left the house was to commute to his college classes. That's it. He has my parents run every errand for him. Now what is even more concerning is the amount of time he spends in his room. Throughout the day he only comes down maybe for 90 minutes in total. All he has in his room as far as entertainment is concerned is a TV with cable as and maybe a few novels.

He also hasn't cut his hair in about 18 months so it is long (past his shoulders) and unruly. The same goes for his facial hair. He hasn't shaved at all or even trimmed it over that time. He also wears the EXACT same clothes every day- jean pants and a sweatshirt. I can't remember the last time he changed them.

However this was "normal" behavior until a couple of days ago. Now he refuses to leave his room AT ALL. I haven't seen him in 3 days now- neither has anyone else in my family and he refuses to talk to anyone. We know he is alright at the moment since he does shoo people away when they try to talk to him. I'm not even sure if he has eaten at all over this time.

The catalyst for this new behavior happened 3 days ago. He brought up that he didn't want to go back to college in the fall (which has already been paid for by my parents) however he does nothing to warrant taking time off so my parents refused and said he has to go. Now he won't even leave his room or talk to anyone. Any advice is appreciated. Should I contact someone about this? If so who do you recommend?

[SWM]

it could be anything and nothing. it is so difficult to understand what is going on the mind of another person when their way of dealing with the world is to disengage. it seems you feel his behaviour is abnormal and your instinct is to seek help. do you feel he is at risk of harming himself?