The Catch 22 is that whereas depression might not be specified, hospital admissions are so you'd presumably have to tick that box? That would require either a note in the further information block or a verbal explanation to the CAA doctor. Therefore go to the medical armed with proof that these admissions were ten years ago and a covering letter from your GP stating that no further treatment had been undertaken or required since then. If your physician can include the fact that depression had never been diagnosed and/or that the admission to hospital was on the basis of voluntary self help then so much the better?
You're not meant to of course but the Hamilton depression scale self check is available on line.