BOSTON ¨C The relative global decline of the United States has become a frequent topic of debate in recent years. Proponents of the post-American view point to the 2008 financial crisis, the prolonged recession that followed and China¡¯s steady rise. Most are international relations experts who, viewing geopolitics through the lens of economic competitiveness, imagine the global order as a seesaw, in which one player¡¯s rise necessarily implies another¡¯s fall.

But the exclusive focus on economic indicators has prevented consideration of the geopolitical implications of a U.S. domestic trend that is also frequently discussed, but by a separate group of experts: America¡¯s ever-increasing rates of severe mental disease (which have already been very high for a long time).

The claim that the spread of severe mental illness has reached ¡°epidemic¡± proportions has been heard so often that, like any commonplace, it has lost its ability to shock. But the repercussions for international politics of the disabling conditions diagnosed as manic-depressive illnesses (including major unipolar depression) and schizophrenia could not be more serious.