In my senior year my GPA is almost a full point lower that it was in previous years owing to the fact that I had to take a second part time job. How much will this hurt me (gpa went from 3.8 to 3.5 in a year), and is it worth explaining why in an adendum?
Assuming the reason is compelling, I would say yes, definitely. As for how much it will hurt you, I think that depends on where you're applying, you're LSAT, etc.
I think with five years distance it matters a lot less