Bipolar disorder affects approximately 1% of the global population, whereas major depression affects 10-17% of the population.

“bipolar disorder is a 1% of the world's population. Compare that to people who have only major depression. So this would be repeated bouts of two weeks or more of serious depression, not just low mood or something due to a life loss, but major depression, which is 10 to 17% of people have major depression.”