I am sorry that I cannot be more specific but I have met people who have been turned down from flying due to any history whatsoever of depression.
I know for a fact that the RAF will not take aircrew with a history, and neither will BA.
This has occurred to people close to me and the best advice I can give you is to telephone the CAA Aeromedical Department and ask to talk to an Aeromedical Specialist. They will help (they are good people!) and will give you the facts, straight. You can be anonymous if you wish, and do not have to go into any more depth than you want. I did this with an eyesight question and they were very good at giving impartial advice.
I hope things work out well for you,
FD