History of mental illness?

I'm been doing my homework and am still interested in trucking. I am kinda worried about being treated for depression 8 years ago. I went to talk to someone, they put me on a 72 hour hold, two weeks later went back into the hospital because of a reaction to meds they put me on. When I got out I took meds. for a few months and was on disability for a few weeks. I have not taken any meds, seen any doctors or had any problems since that time.

Does this count as a history of mental illness?
What about the question on the DOT physical?
What will potential employers say?
Will it show up on a background check or will an insurance company be able to find it?

I am a very health person. Eat right, don't smoke, no drugs and work out 5 times a week. I really want to get into trucking but I don't want to lie to do it. Lying has a tendencie to bite people in the ### and I don't want have to worry about it.

Any input would be greatly appreciated and thanks in advance.