Is conduct disorder a disorder?

Epidemiology is the study of the distribution of diseases and their causes and correlates in defined populations in time and space. It might be better to say that we study the distribution of ‘putative’ diseases (hereinafter referred to as ‘disorders’), because it often happens that what has been thought of as a single disease at one point in time is later recognized as a group of diseases with certain common clinical characteristics. On the other hand, some originally separate diseases come to be seen as being manifestations of a unitary underlying disease process. By a ‘disorder’ we mean a grouping of symptoms, signs and pathological findings (a ‘syndrome’) that is deviant from some standard of ‘normality’. Disease status depends on the disorder being shown to have a distinctive genetic basis, etiology, physical pathology, particular prognosis or specific treatment response (Angold, 1988).

Many psychiatric disorders can be characterized as having a core group of key features around which other symptoms and impairments cluster. For instance, depressed mood is a key feature of depressive disorders. It may turn out that there are some individuals who ‘have’ a disorder but lack its key features, but such cases are anomalous. Conduct disorder (CD) is rather different, because it consists of a group of behaviours, none of which is conceptually central to our understanding of the disorder. The only requirement is that individuals should manifest a lot of these behaviours if they are to be given the diagnosis.