I don't know how it is where you go to school but here at SIU we can provide a letter to records and registration and if there is a semester or 2 that are obviously not like the rest they will drop that semester all together. i.e. if you are a decent student and you have a semester of Ds or Fs and give a letter saying it was because of depression and you were diagnosed they will take off all those classes to return your GPA back to where it was before. I would go to your pdoc and ask for a referral or something stating that you were diagnosed with it and then write a letter of explanation. I agree that you should say something along the lines of "I was diagnosed with (whatever type of depression like anxiety disorder, disthymia etc) on such and such date by so and so." I don't know that I would go into too much detail but it might help if you put in there that you are currently being treated in whatever way that may make them see that you are trying to correct it and trying to do better.