Can you slightly make this easier to understand? keeping all statistics etc.?

The International Pilot Study of Schizophrenia and the Determinants of Outcome of Severe Mental Disorders study used a template of symptoms of psychosis across cultures to identify groups of patients who seemed similar, but these studies left out all those patients who failed to fit the template. It is these excluded patients that Kleinman suggests are of greater interest from a cultural perspective simply because they are the ones who would reveal the greatest amount of cultural diversity. In the International Pilot Study of Schizophrenia and the Determinants of Outcome of Severe Mental Disorders study, catatonia (a form of schizophrenia characterized by a tendency to remain in a fixed stuporous state for long periods) was diagnosed in 10% of cases in developing countries compared with less than 1% in developed countries. Hebephrenia (a form of schizophrenia characterized by severe disintegration of personality) was present in 13% of cases in developed countries and 4% in developing countries. These differences in the disease in developed versus developing countries indicate that there is more to the prevalence of schizophrenia than simple epidemiological data. Better prognosis in developing countries may indicate different sets of aetiological and perpetuating factors. While prevalence studies can help contribute to an understanding of the aetiology of schizophrenia, psychodynamic issues—such as cultural identity and attachment—must also be studied, especially among migrant groups, as cultural congruity and ethnic density may influence the presentation of suffering individuals to psychiatric services