Dr. Brad Hagen, a clinical psychologist and faculty member at the University of Lethbridge, the reason for the skyrocketing rates of depression are a matter of heated debate. “Depending on how you look at it, depression either started becoming more common or recognized, or it became marketed,” says Hagen. Sales of antidepressant drugs worldwide are in the tens of billions of dollars each year. Dr. Hagen says the number of sales is actually quite “mindboggling.”