Is an extremley traumatic event an excuse?

I had got into a major fight with my closest friend,this went on for months.i became extremely depressed. My grades dropped, changed religion,altered my lookout on life, cried myself to sleep every night untill 2am. I even promised myself I wouldn't turn 13. But now we are friends again I just want to know if that would be a legit excuse for slipping up on grades.(my teachers are very awear of the situation)