National differences in psychiatric morbidity: methodological issues, scientific interpretations and social implications

ABSTRACT If national differences in psychiatric morbidity could be established, this information could guide us towards greater understanding of psychopathology and perhaps aid in primary, secondary, and tertiary prevention of psychiatric disorders. Obstacles to determining national differences include application of epidemiological concepts in psychiatry, diagnostic criteria and reliability, sampling and data collection problems, and factors affecting rates which are not constant across nations (e.g., mortality associated with psychiatric disorder, migration). Despite these problems, four diagnostic entities are considered from the standpoint of national differences (i.e., schizophrenia, substance abuse, mental retardation, and pathoplastic or “culture bound” disorders). Three examples of social or “supra‐diagnostic” problems relevant to national differences in psychiatric morbidity are also addressed: youth as a high risk group, homeless mentally ill, and adversive migration.