In our first edition of the Handbook in 1983, we noted that child psychopathology should no longer be viewed simply as a downward extension of adult psychopathology. Rather, we suggested that children must be viewed as children, not as miniature adults, and that a merger of clinical child psychology and developmental psychology must occur in order for this objective to be realized. Now, 6 years later, we are sufficiently encouraged to assert that this synthesis, at least on a conceptual level, is well under way. Yet much growth remains to be seen along practical lines. The real test of the synthesis of these two fields of study will be evidenced on the battlefield, that is, the front line of clinical practice. Just how integrated clinical child psychology and developmental psychology really are remains to be seen. Nonetheless, progress is well under way. Careful attention to developmental and other contextual issues guided us in our efforts to solicit contributors for this second edition. All the contributors are active researchers and clinicians in the area of child psychopathology, and all are keenly aware of the subtle nuances and special considera- tions of clinical and developmental psychology as they relate to child behavior problems. In addition, all the contributors are empirically minded; as a result, the chapters are data-based and represent some ofthe most up-to-date knowledge currently available. However, as research-based knowledge is more abundant and conclusive in some topic areas than in others, the chapters vary in length and scope.