This map visualizes the results of a new study of depression rates. Depression is the second leading cause of disability worldwide, diagnosed in 4% of the human population, and map allows you to compare rates of depression diagnosis across countries.
The map, by the Washington Post, shows the results from a study published in PLOS Medicine. Researchers used preexisting data on the prevalence, incidence, and duration of those diagnosed with Major Depressive Disorder and Dysthymia (also called "Persistent Depressive Disorder). In countries where data was scarce, the researchers estimated the rates using "random effects for country, region, and super-region and fixed effects for country-level covariates such as the mortality rate due to conflict."
The country with the highest rate of depression was Afghanistan. This isn't surprising, unless you still hold on to the urban myth that the Scandinavian countries had a lock on being number one for depression. The lowest rate was found in Japan.
Of course, there are some things that aren't taken into account here. As the Washington Post puts it:
[W]e're not looking at rates of clinical depression, exactly, so much as the rate at which people are diagnosed with clinical depression. People who live in countries with greater awareness of and easier access to mental health services, then, are naturally going to be diagnosed at a higher rate. That may help explain the unusually low rate in Iraq, for example, where public health services are poor. Taboos against mental health disorders may also drive down diagnosis rates, for example in East Asia, artificially lowering the study's measure of clinical depression's prevalence in that region.
The paper also looked to the cause of the rates in the Middle East and sub-Saharan Africa:
In the case of North Africa/Middle East, conflict in the region increased the prevalence of MDD, leading to a higher burden ranking for MDD. In sub-Saharan Africa on the other hand, the larger burden of communicable diseases such as malaria and HIV/AIDs resulted in a relatively lower ranking of MDD and dysthymia.
Shocker, areas with lots of conflict also had lots of depression. And countries ravaged by communicable diseases were far more concerned with whether they had HIV or malaria than depression.
The study didn't just look at rates, but also calculated relative rates of depression as part of a larger study on its "burden."
"Burden" was determined by looking at Years Lived with Disability (YLDs) and Disability Adjusted Life Years (DALYs). YLDs indicate the impact of a life lived with disability, whereas DALYs are the healthy years of life lost due to ill-health, disability, or early death. In this study, DALYs from suicide and depression-related heart disease were separately calculated from general DALYs.
"Burden" generally followed the same trends as the raw depression rates: it was highest in Afghanistan and in Middle Eastern and North African countries, as well as in Eritrea, Rwanda, Botswana, Gabon, Croatia, the Netherlands, and Honduras. It was lowest in prosperous Asian nations, including Japan.
The reason for breaking the results up by country were explained by the study this way:
Our findings not only emphasize depressive disorders as a global health priority, but also highlight the importance of understanding the variations both between and within regions when setting global health objectives. Variations in burden rankings between regions can be masked while considering global-level findings.
This is a laudable goal, since it's easy to see an average of 4% and not realize that there are countries where the diagnosed (not even including the undiagnosed) depression rate is 7% or more. There might also be a focus on depression as a "first world problem," whereas "burden" explains the actual harm done by the conditions.
In addition to looking at country, the study also looked at sex and age. The results show greater YLDs among females than males, and that, for both genders, YLDs due to depression peak in the mid- to late twenties
In conclusion, the paper saw the results as:
Our findings not only highlight the fact that depressive disorders are a global health priority but also that it is important to understand variations in burden by disorder, country, region, age, sex, and year when setting global health objectives. Furthermore, estimating the burden attributable to MDD as a risk factor for other health outcomes allows for a more accurate estimate of burden and reinforces the importance of implementing cost-effectiveness interventions to reduce its ubiquitous burden.
Depression is a real world-wide problem, second only to lower respiratory infections in creating years lost to disability. Unlike other diseases, there's no vaccine or "cure." Just treatment that's missing in a lot of countries with high rates. Plus, it's a disease that many cultures put a taboo on seeking help for. But it's a real public health concern.