Richest Countries Have Most Depression
The World Health Organization predicts that depression is set to become the second leading cause of disease by 2020. Depression rates globally have always tended to vary and it has always been assumed this relates to genetic and cultural factors as much as differences in methods used to collect data. Despite these differences nearly all studies point to gender, age and marital status as having some association with depression. On average, at least in Western countries where most information has been gathered, it appears that women have double the risk of depression. Separated or divorced people have significantly higher rates of depression than those in a stable relationship and rates of depression tend to reduce with age.
Recent results from over 89,000 interviews collected from 18 countries has revealed that 15 percent of the populations from high-income countries are likely to be diagnosed with one or more major depressive episodes compared with 11 percent from low-to-middle income countries. Of interest is the fact that some of the highest rates of major depression were found in the wealthiest countries, e.g. America, France, the Netherlands (30%). The lowest incidence of major depression was in China (12%) but the highest reports came from India (36%). Age of onset of depression is approximately two years earlier in low income countries.
It has always been suspected that rates of depression are generally higher in more affluent countries. Some observers view depression as a disease of affluence and others suggest that income inequality, which is far more evident in affluent countries, promotes a range of chronic conditions that includes depression.
A person with major depressive disorder will usually have a very low mood and an inability to experience pleasure in activities that were formerly enjoyed. Ruminating over feelings of worthlessness, inappropriate guilt or regret, helplessness, hopelessness, and/or self-hatred are features. In very severe cases, symptoms of psychosis may be present, most often delusions (fixed false beliefs). Additional symptoms include poor concentration and memory, withdrawal from social situations, reduced sex drive, suicidal thoughts.
Bromet, E., et al. Cross-national epidemiology of DSM-IV major depressive episode. BMC Medicine 2001, 9:90