Can losing a sibling end in psychiatric problems?

Over the past while I've heard the same thing in regards to people who have social issues.

for example, guy at work went out on a night out and presumably due to too much drink taken verbally abused everyone there including some of his best friends to the point that they won't socialise with him any more even though he's apologised to them.

Next example is a girl who is an absolute b*tch to everyone around her, especially those junior to her. To the point that numerous complaints to HR have been made about her and she's been moved roles so that she doesn't have to directly work with anyone.

These are just two examples of more situations where when others have discussed who know the people better say something along the lines of, they've never been right since they've lost their brother/sister etc. It's an issue I've heard a lot of lately.

So, my question is, what's your opinion? Does a far higher percentage of people who lose siblings when young develop social issues and is there enough support there when these things happen?