Certain kinds of depression and mood swings are different from ordinary feelings of sadness and high spirits, and doctors identify them as bi-polar illness, or manic depression. All sufferers will find this book invaluable. It describes the causes, symptoms and treatment of depressive moods, how to recognise mood swings and why it is so important that depression should be properly diagnosed and treated. There is advice for sufferers and their families to help them cope day to day, and information about the related problem of Seasonal Affective Disorder - the 'winter blues'.