Depression Incidence and Prevalence
The incidence of depression has risen every year since the early 20th century. There are probably many reasons for this, though most studies point to significant socioeconomic changes experienced by the post-World War II "baby boomer" generation.
In the United States, one in six people experience a depressive episode during their lifetime. Only 50% of the people who meet the criteria for diagnosis seek treatment for depression, which affects the ability to determine how many people actually suffer from this disorder.
Depression Prevalence Among Countries
The reported prevalence of depressive disorders varies throughout the world. The lowest rates are reported in Asian and Southeast Asian countries. Percentages represent the lifetime chance that a person will experience a depressive episode that lasts a year or more. For example, Taiwan reports less than 2%, and Korea 3%. Western countries typically report higher rates, such as Canada 7%, New Zealand 11%, and France 16%. The United States has a rate of 6%. Also, countries plagued by protracted civil war, such as Bosnia and Northern Ireland, report higher rates of depression.
Low rates of depression in Eastern countries such as Taiwan may correspond with low rates of divorce and separation. However, it is possible that, divorce and separation are not publicly acknowledged as often in the East.
Culturally based differences in the perception of symptoms of depression also influence statistics. For example, Eastern people may describe depression as a series of pains, loss of focus, or an imbalance in their energy, rather than as a mental health disorder.