In 2018, researchers around the world worked tirelessly to combat a range of mental health issues.

Scientists found more effective treatments for post-traumatic stress disorder and further delved into the relationship between sleep and depression.

Previously under-researched drugs such as ketamine, marijuana, and ecstasy became the main focus for many researchers when seeking potential treatments for anxiety and depression, among other mental health concerns.

Approximately one in five adults in the US — 43.8 million — experiences mental illness in a given year, according to The National Alliance on Mental Illness. That being said, it's no surprise that each and every year researchers put time and enormous amounts of money into tackling the growing mental health crisis.

It seems in 2018, much of their hard work paid off — around the world researchers crumbled myths and opened new doors as they aimed to better comprehend the complicated world of invisible illnesses.

Here are 10 of the most important things we learned about mental health in 2018.