The most prominent psychiatrist around here is Daniel Pine, who is at the Ross Center and at NIH. I'm not sure if he's taking new patients, but there are other psychiatrists at the Ross Center who are also good. Here is a list of some others:
http://www.bethesdapediatrics.com/referrals/psychiatry
Be aware that most psychiatrists do not take insurance. And IME, the few who do are not the ones who will carefully walk you through this process. The first appointment should be 60-90 minutes and should include time with your DC alone, parents alone and everyone together.
It seems that you have a strong bias against medication. The evidenced-based treatment for moderate/severe depression is a combination of CBT and meds. Most people start with therapy alone first. There can be other factors (such as BCP for girls which can regulate hormones and may help), exercise is particularly important, but a good psychiatrist will help you look at your child's level of functioning to see how aggressively the depression needs to be treated.
Medication can be life changing. My DC went from being almost non-functional - not leaving the house, barely even getting out of bed - back to almost normal life, working, going to school, having friends. Depression is something DC will always struggle with, but before the meds, DC was not able to engage in therapy or exercise or any of the things that also help. Sometimes the meds lift the cloud enough for the child to be able to start helping him/herself.