My boyfriend was put on prednisone for an allergic reaction to an...

Hi, don't worry, your friend wasn't taking prednisone for a long time, and therefore, its side effects will subside in a matter of days to a few weeks. Yes, when corticosteroids are used, psychic derangements may appear ranging from euphoria to severe depression, but those will disappear (after corticosteroids are discontinued), so, don't leave your boyfriend during the time when he may need your support and understanding the most.

That's right, he hasn't been on it too long, but long enough that it's in his system and he would have experienced the side effects of it. When you first start taking it you feel ephoric and energized, at least that is how it was for me. After being on it for a few weeks at a high dose, I started feeling moody, aggressive, emotional etc. My husband said I had "roid rage" to, lol, but it's not something you can help. You think and act irrationally, and you don't even know you are doing it. How much was he taking btw?