Churchill and JFK’s struggles with mental health benefited the world, but mania in a leader can also lead to disaster.

In 1938, British Prime Minister Neville Chamberlain stood before the House of Commons to make an announcement. He would travel to Germany to meet Hitler in an attempt to convince him of the unnecessariness of war.

MPs jumped up and cheered at the plan. But Winston Churchill remained seated, despite others rebuking him for not joining in.

Churchill had his reasons. In 1930, long before anyone else in British government came to the same conclusion, Churchill had recognized the Nazis’ threat. They were a danger to world peace.

In the author’s professional opinion, Churchill likely had type II bipolar disorder. This resulted in several manic and depressive phases.

Therefore, in the author’s eyes, Churchill’s depressive experience meant he was able to discern situations realistically. In comparison, his mentally healthy colleagues’ optimism was misplaced.

The thirty-fifth president of the United States, John F. Kennedy, is also an interesting figure. For the author, JFK exemplifies hyperthymic personality disorder. Simply put then, he was a hyperactive and creative risk-taker – with a sex drive to match.

This was particularly in evidence during the Cuban Missile Crisis in October 1962. The Soviet leader Nikita Khrushchev sent Russian nuclear missiles to Cuba to goad Kennedy into a pre-emptive strike – with atomic weapons.

But Kennedy held firm. He ignored the advice of everyone around him. By doing so, he averted nuclear disaster. Other leaders who might not have had Kennedy’s experience with mental health struggles would probably have acted differently. No doubt they would have shared the natural impulse common among Kennedy’s advisers and ordered a preemptive attack.

Adolf Hitler is another world leader worth considering when thinking about mental health. The author is certain that Hitler had bipolar disorder. But what really caused the evils he leveled on the world was his vile ideology mixed with an overreliance on methamphetamines.

Certainly, Hitler suffered from bouts of mania and depression during his childhood. It’s thanks to his friend August Kubizek that we know this.

Hitler had always had an aggressively megalomaniacal streak, but it was as a leader capable of manipulating the masses that he found his feet. The author even argues that his demagoguery might have been facilitated by his personality disorder.

It’s also worth remembering that Hitler’s aggressive and maniacal behavior went into overdrive from 1937 onward. That’s when his doctor started prescribing him methamphetamines.

It’s quite possible that Hitler’s prolonged use of methamphetamines heightened his mental instability. Consequently, over time he became less and less likely to listen to the advice given to him by subordinates. His outbursts of violent rage also became more frequent.