King George III of England and Queen Maria I: bipolar disorder and prince regents as commom features in their reigns

Humanity is sporadically subjected to leaders with deviant behavior, ego problems, or psychiatric disorders, potentially leading to social instability. Bipolar disorder is not common in all populations, but coincidentally, studies suggest that it affected two sovereigns that were contemporaries, King George III of England, who died 201 years ago, and Queen Maria I of Portugal, who died 205 years ago. They lived during a time of European turmoil with the French Revolution and Napoleonic Wars, coinciding with the rise of psychiatry. Both monarchs were forced to have prince regents to rule in their place, due to their emotional decline, and they shared the same medical consultant, Francis Willis.