Persephone was a Shaman

Someone who can travel back and forth in between worlds. 

This describes a Shaman. 

It also describes Persephone. 

Most stories that include Persephone focus on her as a maiden goddess who was abducted by Hades, the god of hell, into his dark and dangerous Underworld. What is overlooked is that this young, purportedly naive and clueless girl was actually a powerful feminine force, who spent her time in hell making sure that she could see in the dark. When she was finally returned to the land of the living, she used her powers to guide those who were also afraid of the dark. 

Today, we call these people therapists, psychiatrists, all good folks who want to help people navigate the darkest buried parts of their souls. But we forget about the original therapist: the shaman. Long before DBT, cognitive approches to therapy and psychotropic drugs to help those suffering from depression and other mental illnesses, there were shamans. These were the people who had suffered from depression, from suicide attempts, from psychosis. Having survived, and having learned to see into the depths of their own darkness and be brave enough to excavate the treasure buried in the shadows, they used it to help others. 

Persephone is a timeless model for having the courage to explore one's underworld. She may have been forced into a situation she did not seek, but having found herself in a world of darkness, instead of panicking, she used her time wisely. She became familiar with the darkness, and within the shadows, she located the biggest treasure of all: self knowledge. 

The ancient Greeks were very familiar with this concept, and inscribed an epithet at the sanctuary of Delphi that says:

Gnothi seauton

 (Γνῶθι σεαυτόν)

Know Thyself