Immigration & Bipolar Disorder

I have mentioned this study before, which found significantly different rates of bipolar disorder between nations.  Having trouble sleeping, I suddenly noticed an interesting correlation.  Of the six nations with the highest rates of bipolar disorder, four are New World nations: Brazil, the U.S., Mexico, Colombia; a fifth is also a nation of immigrants: New Zealand.   Bipolars are risk takers, and immigrating to a new country is definitely a risk taking enterprise.

The plus side of bipolar disorder is that subthreshold BP includes a lot of very creative and energetic people who are disproportionately CEOs.  Downside is that those above the threshold are disproportionately murderers, and I suspect day traders, and other forms of destructive gamblers.  This might explain high rates of violence in most of these countries.