One of the most important practical problems in child psychology and psychia­ try is the differential diagnosis of emotional disorders. Until recently, the gener­ al mode of assessment had been to apply to children the characteristics of psychopathology that were evident in adults. In addition, there had been few assessment tools available for use with children aside from modified versions of adult instruments. Understandably, this approach was controversial, and dissat­ isfaction with it led to the more recent knowledge that adult and child problems may be manifested quite differently. The third edition of the Diagnostic and Statistical Manual of Mental Disorders takes these factors into account much more extensively than previous editions. Furthermore, a great deal of research on methodology in child assessment procedures has emerged recently. Yet, in spite of these advances, practicing clinicians are still frequently at a loss in moving from the characteristics of the disturbed child before them to the final assign­ ment of a psychiatric diagnosis. The focus of this book is to outline the various methods of viewing and categorizing the wide range childhood psycho­ pathology, with special emphasis on the end product of making a differential diagnosis. Our goal was to make this book unique in several ways. First, we attempted to cover a wider range of disorders than is typical in currently available handbooks.