WIDESPREAD depression is a cause of concern to psychiatrists. According to the book, Down with Gloom or How to Defeat Depression, by Brice Pitt and Mel Calman of the Royal College of Psychiatrists, one in eight people may be significantly depressed at any one time. At least half go unrecognised by general practitioners, but two million new cases are still found in Britain every year. Even more alarming is the fact that, of the 4,000 suicides a year, 70 per cent are triggered off by depression.