The DSM-IV, the U.S. standard reference for psychiatry, includes over 300 different manifestations of mental illness. Psychiatrists themselves are in dispute over how common some of these conditions are, or whether they should be listed as 'mental illnesses', and each version of the DSM is slightly different to the previous ones. The DSM-IV is currently being revised and updated, and I have no doubt that the next version will include new-and-improved manifestations of illness. This is a portion of the currently recognised list of mental illnesses.
... monk and author of "Imitation of Christ", one of the most well known Christian books on devotion.
I. Life, Minor Writings
Thomas à Kempis, German mystic and ...