Problems involving disruptive behaviour constitute one of the most frequent causes of clinical referral. The preceding chapters of this volume provide a most useful, and interesting, range of perspectives on the issues to be considered with respect to such disorders. In this concluding commentary chapter, some of the key issues that span the different chapters are pulled together. In so doing, research findings are used to draw conclusions on what is known now as well as to highlight research and clinical needs for the future.

Do conduct problems constitute a valid psychiatric disorder?

Over the years, doubts have frequently been raised on this issue (Richters & Cicchetti, 1993). The uncertainties are certainly understandable. The fact that someone behaves in ways that are socially objectionable does not provide a justification for regarding the behaviour as reflecting a mental disorder. What criteria might be used? Possibilities include associated social impairment, accompanying unusual psychological features (such as hyperactivity/inattention or cognitive impairment, or depression) and an adverse outcome in adult life. On all of these criteria, the findings seem to justify a disorder concept (Rutter et al., 1997b, 1998; Maughan & Rutter, chapter 18, this volume). Of course, that is not to argue that any isolated antisocial act justifies the designation of disorder. Obviously, that could not be the case, if only because most people commit such an act at some point during their lifetime (Rutter et al., 1998).