Four years have passed since the last edition (3rd) of this book was published.  In the intervening years, several reviews of this book have provided highly encouraging remarks about the value of this book in transmitting information on classification and treatment of psychiatric disorders to the audience. We are proposing to revise all chapters with an eye on accuracy and ease of use, and this is an especially timely endeavor with the upcoming publication of the Diagnostic and Statistical Manual V. All the appropriate new information on biology, etiology, diagnosis and treatment of psychiatric disorders will be added to the current proposed edition. It is our goal to recruit the same authors (if possible) who contributed to the previous edition.  While all chapters will be updated (see TOC), those marked by asterisks will be the most likely to undergo more revision.