Black Dog Paternal Depression

This is what a business in Australia was looking for in their poster design

We are a small group of undergraduate midwifery students and one of our assignments is to develop a poster for a specific issue.
We have chosen to focus on Postnatal Depression for fathers as there is little focus on their mental health and emotions following the birth of their child.
We have a concept in our mind and I'll attach a brief sketch for your perusal.
A roller coaster, the cart contains a little black dog in reference to the Black Dog Institute. We are thinking that the rails of the roller coaster get thicker as the line continues - indicating that that they are getting bogged down. The emotions are up and down. "How low will you go ... before you get help?". A logo for Black Dog Institute at the bottom.
Thinking black and white theme, unsure whether to have white poster with black drawing or black poster with white drawing. Read more