Decoding schizophrenia across cultures: Clinical, epidemiological and aetiological issues

Abstract

There is accumulating epidemiological evidence of cross-ethnic differences in relation to schizophrenia’s incidence and prevalence. However, there is a dearth of information about the manifestations of cultural differences in schizophrenia’s symptoms. This thesis aims to bridge the gap in our knowledge about the relationship between cross-cultural differences and schizophrenia. Throughout this thesis, I explore the similarities and dissimilarities of the content of clinical manifestation across cultures. I also examine and further develop epidemiological and clinical issues utilizing the ecological theory model. First, I perform a qualitative systematic review which includes 26 publications. I then discuss findings from a statistical analysis of a mental health population of 860 patients in Brent, North London. Lastly, I report results from a semi-structured mental health questionnaire that was devised and disseminated to 48 mental health professionals in London. Results indicate that ethnic groups which experience a higher incidence of schizophrenia also tend to display more positive or first rank symptoms. These ethnic groups that experience a higher incidence of schizophrenia also belong to cultures that culturally legitimise an externalization of their distress. On the other hand, it was found that cultures that internalize their distress experience lower incidence of schizophrenia. My research further demonstrates that schizophrenia’s interpretations are heavily dependent on the diagnosers’ own cultural background, and on the degree to which the externalization of a symptom is tolerable in that context. Furthermore, evidence of intra-cultural diversity in clinical settings underscores the importance of achieving higher cultural competence.