The 19 unhappiest countries in the world

The latest findings of the World Happiness Report, an annual survey that assesses the state of global wellbeing, have been released ahead of the United Nations' International Happiness Day on March 20.

To determine its results, the report gauged the happiness levels of thousands of individuals from 156 nations from their responses to the Gallup World Poll.

Countries were ranked according to six key criteria: GDP per capita, social support, life expectancy, freedom to make life choices, generosity, and freedom from corruption.

The report also considered happiness inequality, to see how happiness levels varied between people from the same countries.

"The reports review the state of happiness in the world today and show how the new science of happiness explains personal and national variations in happiness," the report reads. "They reflect a new worldwide demand for more attention to happiness as a criteria for government policy."

Here are the 19 unhappiest countries in the world.