We thank Dr Mushtaq for his comments on our article. ^{Reference Pascual, Malagón, Córcoles, Ginés, Soler and García-Ribera1} Although we agree with his comment that it is unlikely that immigration could be a risk factor for developing borderline personality disorder, we think that this issue is still open to debate.

First, other authors such as Paris ^{Reference Paris2} have suggested that the process of migration from traditional societies to Western countries could result in the development of borderline personality disorder in individuals who did not present any symptoms in their country of origin. Paris considered that although individuals could have a biological predisposition to this disorder, such as an innate affective instability, the structure of traditional societies tends to suppress the kind of psychopathology seen in borderline personality disorder. Once these patients emigrate to Western countries, this sociocultural suppression disappears. ^{Reference Paris2} In contrast, Tyrer et al ^{Reference Tyrer, Merson, Onyett and Johnson3} and Baleydier et al ^{Reference Baleydier, Damsa, Schutzbach, Stauffer and Glauser4} observed a lower incidence of personality disorders in immigrant patients admitted to psychiatric emergency services. Likewise, in a previous study that was not centred on an immigrant population, we found that patients with borderline personality disorder were less likely to be immigrants. ^{Reference Pascual, Córcoles, Castaño, Ginés, Gurrea and Martín-Santos5} For this reason, we performed an exploratory study (i.e. without an initial hypothesis) to examine whether there really was an association between immigration and borderline personality disorder, where immigration could either be a risk factor or have a ‘protective’ effect. ^{Reference Pascual, Malagón, Córcoles, Ginés, Soler and García-Ribera1} Despite the fact that, in our opinion, we observed a ‘protective’ association for immigration on the development of borderline personality disorder, our results do not invalidate Paris's hypothesis. In Spain, immigration is a relatively new phenomenon, and the majority of patients we evaluated were adults from poorer countries who were not yet totally immersed in Western culture. It is possible that in younger immigrants (whose personality has not yet been totally consolidated) or in second-generation immigrants, a higher prevalence of borderline personality disorder could eventually be observed, as suggested by Paris. ^{Reference Paris2}

Second, another important point of our study is that the immigrant sample must not be considered as a homogeneous group, since important differences exist between the subgroups of immigrants according to their geographical origin. For instance, patients from sub-Saharan Africa and Asian countries were more than seven times less likely than other immigrants to be diagnosed with borderline personality disorder. Therefore, it could be suggested that certain cultural differences in these regions, for example a greater tolerance of suffering, could be useful factors to prevent the development of this disorder. The identification and analysis of these ‘protective’ cultural factors could offer future tools to prevent the appearance of borderline personality disorder in Western societies.

We would also like to highlight that although we share Dr Mushtaq's opinion that it is unlikely that immigration may be a risk factor for borderline personality disorder, the empirical evidence so far is not only scarce but also somewhat contradictory and with important methodological limitations. In fact, our own study presents some of these limitations. To confirm our findings, more methodologically rigorous studies would be necessary.