50mg is a pretty low dose for sertraline...when I was started on it they put me straight on 100mg because they didn't see the point of me being on 50mg first. I don't think it helped me until I got to 150mg.

I agree with my depression diagnosis...but have been fighting another diagnosis I got 4 years ago. If it doesn't sit right with you then you should ask why that professional diagnosed you and also let them know the reasons you disagree. Perhaps a discussion will clear things up...whether it leads to you agreeing with depression or the doctor rethinking the diagnosis.