This paper by Kathleen Rees Merikangas and others (full abstract is linked to above) is important as an extremely large study examining the occurrence (prevalence) of bipolar disorder (type 1, type 2, subthreshold bipolar and bipolar spectrum – including all three) in an community sample of more than 61,000 people spread over 11 countries who were interviewed face to face.
Much of what we know about the frequency of occurrence of bipolar disorder and its impact on those who are affected has been derived from work carried out in Western Countries such as the USA or in Europe.
This study is important as it examines at the same time, using the same methodology the rates of occurrence and the impact of bipolar disorders in 11 countries across the world raging from the high to middle income countries such as the US to low income countries in the developing world. It also does not just look at how frequently bipolar disorders occur, but examines the degree of impact they have upon the lives of those who are affected by them. It also examines the proportion of affected individuals in touch with support services.
The take home messages are:
- Although bipolar disorders vary to some degree between countries, a consistent finding across all countries was that less than 50% of people with a detectable bipolar spectrum disorder were in touch with any form of mental health services. This was as low as 25% in low income countries.
- In this study the highest rates of bipolar disorders were detected in the sample interviewed in the USA.
- Despite the variation in rates of bipolar disorder between countries found, the degree of impact upon the lives of those who were affected was similar between countries.
- Individuals with Bipolar Spectrum Disorders commonly had other significant psychiatric disorders, particularly Anxiety Disorders.