En Belgique, selon la loi de Défense Sociale (1964), les délinquants malades mentaux reconnus incapables de contrôler leurs actes peuvent être internés et doivent par la suite être orientés vers un Établissement de Défense Sociale (EDS). Ils sont supposés recevoir un traitement et un accompagnement en vue d'une réinsertion sociale. L'article se focalise plus particulièrement sur l'expertise en Défense Sociale (DS). Il débute par un rappel des aspects légaux. Il décrit ensuite les caractéristiques diagnostiques d'un échantillon de patients internés (n=98) en insistant sur l'importante comorbidité clinique en termes de troubles mentaux majeurs (axe 1) ainsi que de troubles de la personnalité (axe 2). Il aborde ensuite la prévalence hypothétique de la psychopathie (PCL-R, Hare, 1991, 2003) dans le cadre de la loi (5-8 %). Il souligne ensuite des points susceptibles d'améliorer les pratiques d'expertise en Défense Sociale.

Under the Belgian Social Defence Law (1964), mentally disordered offenders who are deemed to lack criminal responsibility have to be interned in an ‘Institution of Social Defence' rather than in a prison. There, they are supposed to receive specialised treatment before their rehabilitation and re-insertion into the community. This paper discusses expertise practice in relation to the Social Defence Law. The paper first gives a description of the requirements of the law. The paper then presents the prevalence of clinical syndromes (axis 1) and of personality disorders (axis 2) among a sample of internees (N=98). The sample presents a high co-morbidity (2.6) of axis I syndromes, and of axis 2 personality disorders (1.7), the majority of them (64%) present both axis diagnoses. The paper also discusses the prevalence of a high psychopathy as measured by the PCL-R among internees (5-8%) as compared to prison inmates given the aim of the law of protecting the society against dangerous individuals. The paper shows that the Social Defence Law embraces a very large spectrum of psychiatric diagnoses including personality disorders and psychopathy. The following recommendations could improve expertise practices: (a) the consideration of earlier propositions relating to the improvement of the Social Defence Law; (b) a comparative research between psychiatric diagnoses of internees and of inmates; (c) a better definition of clinical criteria relating to the application of the law; (d) the implementation of a specialised observation unit before the decision to intern; (e) the need to go beyond a dichotomous conception of the ability to control; (f) the consideration of contextual factor of dangerousness; (g) encouraging the use of validated risk and clinical assessment instruments; (h) a better financing for expert work.