The epidemiology of borderline personality disorder: the state of the art

Borderline personality disorder is a heterogeneous disorder with a complex mix of polythetic criteria. It is to be expected that prevalence figures are likely to vary.  Despite this there is general agreement that the prevalenc e of the disorder in the community is just under 1% of the population, but in medical settings of all kinds it is a great deal higher, with more that half of all patients with the condition seeking treatment of some kind in any one year.  Between 7 and 27% of those attending out-patient psychiatric clinics also have borderline personality disorder. There is also a curious paradox that most studies suggest that borderline personality disorder is much more common in women but in the most representative national community surveys it is more common in men.  A great deal of the variation in figures is related to comorbidity; pure cases of borderline personality disorder are rare and it is how the mixed cases are formulated is the clue to understanding the figures.  Ways of improving the data base for the disorder will be discussed.