Note: As Mike Yassa, the lead author on the study, pointed out to me, the study did not actually test whether consuming caffeine before a task enhances memory, the problem being that other confounding factors can then lead to difference in performances on the test.
The US debt is more than $20.1 trillion, the largest in the world. Here are the 3 reasons it grew so large, and how it damages U.S. economic growth. The US debt is more than $20.1 trillion, the largest in the world.
Total Federal Government Debt in 2017. Click image to customize chart. and view data. At the end of FY 2017 the gross US federal government debt is estimated to be $20.1 trillion, according to the FY18 Federal Budget.