Epidemiology of depression in diabetes: International and cross-cultural issues

Introduction: This paper reviews the most up-to-date epidemiological evidence of the relationship between depression and diabetes, and considers the risk factors for the development of depression and the consequences of depression in diabetes with an emphasis on international and cross-cultural data. The difficulties that researchers face when epidemiological studies require assessment of psychological phenomena, such as depression, across different cultural settings are explored. Methods: Relevant papers were sought on the epidemiology of diabetes and depression in people with diabetes by undertaking a literature search of electronic databases including MEDLINE, Psych-INFO, CINAHL and EMBASE. These papers were assessed by the authors and a narrative review of the relevant literature was composed. Results: Systematic reviews of the prevalence of depression in people with diabetes have focused on studies conducted in English speaking countries and emerging data suggest that there may be international variations in prevalence and also in how symptoms of depression are reported. There appears to be a bi-directional relationship between depression and diabetes, with one influencing the other; however, research in this area is further complicated by the fact that potential risk factors for depression in people with diabetes often interact with each other and with other factors. Further research is needed to elucidate the causal mechanisms underlying these associations. Limitations: Data from non-English speaking countries remain scarce and so it is difficult to come to any firm conclusions as to the international variation in prevalence rates of co-morbid diabetes and depression in these countries until further research has been conducted. Conclusion: It is important to take a culture-centered approach to our understanding of mental health and illness and consider the key issues related to the development of culturally sensitive depression screening tools. In order to come to any firm conclusions about the international variation in prevalence of co-morbid diabetes and depression, issues of culture and diversity must be taken into account prior to conducting international epidemiological studies. (C) 2012 Elsevier B.V. All rights reserved.