America has the highest rates of bipolar disorder
Posted Mar 22, 2011
America has the highest rates of bipolar disorder according to an eleven-nation NIMH study published in this month's Archives of General Psychiatry. In reporting on this finding CNN noted that the hypomanic nature of the American character has "been the subject of at least one book. In ‘The Hypomanic Edge: The Link Between (a Little) Craziness and (a Lot of) Success in America,' by John D. Gartner, Ph.D. Gartner, an assistant professor of psychiatry at Johns Hopkins University School of Medicine in Baltimore, discusses the hypomanic qualities of entrepreneurs and leaders who took risks to come to America." In that book, I argued that a high concentration of hypomanic genes is the secret source of America's wealth and character. This new study provides critical validation for several my theses, that admittedly were somewhat speculative at the time.
My first thesis was that entrepreneurs, the people who generate the most wealth for a society, are much more likely to have what I called a hypomanic temperament. People with this biologically based temperament have, as a stable trait, heightened energy, drive, ambition, confidence, creativity and risk tolerance and are thus more likely to be the kind of charismatic visionary leaders who start enterprises of all types, including businesses. My second thesis was that America has a higher proportion of hypomanics than other nations because we are a nation of immigrants, and immigrants are unusual people (making up only 1% of the world population) who are a as a group more ambitious, restless, energetic, and optimistic than average, with the get up and go to get up and come here. Supporting this idea, studies have found immigrants to be unusually high in bipolar disorder. People like this generate wealth, and so nations who have a lot of them have more money.
If you populate a continent with such a highly skewed self-selected population you have a brilliant natural experiment evidencing what I call the "immigrant effect." A joint study by Babson College and the London School of Economics found that the nations highest in new company creation per capita were America, Canada, Israel, and Australia: all nations of immigrants. In the middle were the European nations, which are in the middle in immigrant absorption. And dead last were the Asia nations, which have negligible immigration rates. The cross cultural studies of bipolar disorder that then existed followed almost exactly the same pattern, with immigrant nations like US and Canada in the lead, Europe in the middle and Asian nations last. Thus I concluded that more immigrants= more hypomanics=more national wealth. There was something about this thesis that felt intuitively right.
People seemed to get it right away. And it indeed seemed to explain a lot about the American character and economy (we were still in the midst of the internet mania hangover when the book came out in 2005), and for that reason the New York Times Magazine Year in Ideas issue, named "the Hypomanic American" one of the best new ideas of 2005. However, not everyone stood up and cheered. The more skeptical (some would say the more sophisticated), including my reviewer in the New York Times Book Review, found some of the supporting data thin, and they were, unfortunately, not entirely wrong.
There were at least two problems with the data that existed at that time I wrote my book that have been solved by this study. First, it was hard to know whether the cross-cultural data on bipolar disorder was an artifact of how the disorder was measured. This study used the same validated measure in all eleven countries, so we know we're not comparing apples to oranges. Second, none of the studies I cited looked at cross cultural rates of hypomania. I presumed that where you have more bipolars, more hypomanics are sure to follow, because from what we can see the two seem to run together in families and are thus probably genetically linked. But that was a leap of inference on my part.
This new NIMH study assessed more mild manic states and found that America had the highest rates at all levels of the bipolar spectrum: Bipolar type I (1.0%), type II (1.1%), and subclinical bipolar traits (2.4%), with a total of 4.4% of Americans falling somewhere in the bipolar spectrum, almost double the international average of 2.4%. The next closest nation was New Zealand, the only other nation in the sample that was predominantly populated by immigrants. By contrast, India, which receives virtually no immigrants (indeed the best and brightest often immigrate out of India) had a shockingly low rate of .1%, making an American 44 times more likely to be on the bipolar spectrum than a citizen of India! This is a gigantic effect size making this finding not only statistically significant, but clinically and socially significant as well. David Schlager, M.D., an assistant professor of psychiatry at the Texas A&M echoed the logic of the Hypomanic Edge when he told CNN: "The U.S. attracts people who believe they can achieve a better life. They come to believe they can pick up and start again. It's a self-selected sample of people who are grandiose and impulsive. It takes a certain suspension of belief to actually believe you can come here and make it happen. Those are a significant percentage of people on the bipolar spectrum."
The study noted another pattern: Rich nations showed higher rates of bipolarity than poor ones. The logic of my thesis would also predict this, since I contend that people on the bipolar spectrum make a nation rich. But of course, other explanations are possible as well. The studies lead author, Kathleen Merikangas, suggested that one interpretation might be that poorer countries offer some "protection" against bipolar disorder that the U.S. lacks, such as traditional social structures that are still relatively intact. "We have less buffers in terms of social networks, in terms of having strong family backgrounds," says Merikangas. Perhaps, but we've found few areas of life where coming from an impoverished nation provides "protection." It is almost always the other way around.
In a blog here on Psychology Today entitled, "Highest Rates of Bipolar Disorder in the United States: Why?" by Robert J. Hedaya offers a different explanation for America's high bipolar rates. Income inequality, he argues, is a special form of stress that makes poverty more psychologically destructive than it would be in other more uniform countries. "We have the largest gap between rich and poor, so the economic stresses on a large part of the population are greater than in other western societies. This translates into psychological stress, more substance abuse, poorer quality nutrition, and fragmentation of the family." But if this were correct we would find the bulk of bipolar disorder in Americans to be among the poor, the opposite of what we know to be true. In fact, one of the more oddly reliable findings in psychopathology research, dating back some 40 years across dozens of studies, is that bipolar disorder is the only disorder where, as a group, patients have above average incomes, where every other disorder studied is associated with reduced income. It's not a large effect, but it is consistent. If you look at the families of bipolar patients, where presumably there are above average rates of hypomania, we find dramatically higher than average incomes.
There are several important implications of these findings for our nation. Our immigrant heritage has made us rich, and so we might want to think more kindly of today's immigrants who are not "using all our resources," as the more xenophobic contend, but just the opposite. Today's immigrants are creating wealth for America by bringing with them their energy, ideas and drive to succeed. Secondly, while America may epitomize the positive side of hypomania, creativity, energy, optimism, drive, we also express its dark side. America is also known for its arrogance, misplaced messianic zeal and shoot from the hip impulsivity. The world loves us for our hypomania, and they hate us for our hypomania too-basically the same reaction most individual hypomanics get. We live by our hypomania, but we must take care that we don't die by it as well.