Accurate comparisons of the prevalence of psychiatric disorders across Eastern and Western cultures are difficult and limited by methodological problems. Nevertheless, using standardized diagnostic and evaluation techniques, recent surveys have suggested that depression and anxiety disorders exist in all countries and cultures examined thus far, although variations in the prevalence rates and symptomatology may exist. This article discusses the influence and impact that culture can have on recognizing and treating mood and anxiety disorders, with a particular focus on Japan. Over the last 20 years, studies have consistently reported an increase in mental illness in Japan, especially symptoms of depression and anxiety. While such symptoms have had an adaptive cultural role in the past, current social and economic changes in Japan have turned any adaptive advantage into a potentially significant disadvantage, with a major impact on the capacity of individuals to function adequately. The situation is compounded by the fact that Japanese patients are reluctant to openly discuss disturbances of mood, since these are considered to be indicative of personal weakness rather than treatable medical conditions. Reluctance to discuss personal mental health hinders timely recognition and appropriate treatment.