My friend was diagnosed with depression after a suicide attempt, and ever since then he will lash out at anyone who provokes him, even if it's just a tentive "hi". Are these related or two seperate disorders?
Perhaps he knows and can tell you. Otherwise you would have to get specifics from the person who diagnosed him and unless he gives you permission then that is impossible.
There are many possibilities since depression is different for each person, so any link with depression and the angry behavior right now can't be generalized.