He’s been like this ever since Dad’s death... I don’t think it’s because of the death that he’s secluded himself, though; he and my father never had a very good relationship, as neither was really willing to take the first steps towards making anything happen. What I’m more thinking is that Dad’s strictness was what kept his seclusion in check, forcing him to come out once in a while.

That said, I’m not ruling out the possibility that he’s mourning in his own way. I just find it unlikely. Regardless of what’s going on, I’m definitely concerned. :(