Epidemiology of personality disorders 

tbegun to be scientifically investigated. This development has taken place because a number of standardized instruments to assess personality and PD in an empirical fashion have been developed, in parallel with the refinement of a valid and reliable diagnostic system based on a categorical approach. The need for the epidemiological investigation of PDs seems justified for several reasons. 1 As seen in recent epidemiological surveys, PDs are frequent and have been found in different countries and sociocultural settings. 2 PDs can seriously impair the life of the affected individual and can be highly disruptive to societies, communities, and families. 3 Personality status is often a major predictive variable in determining the outcome of Axis I mental disorders and the response to treatment. In this chapter, we review the epidemiological literature on PDs up to October 2007, focusing on studies carried out since the development of the DSM-III. First, community prevalence studies of PDs are reviewed. We then look at the prevalence of individual PDs in the community. Finally, we consider the prevalence of PDs in clinical populations, and in special settings (e.g. primary care, prisons, etc.).