Over 300 million people around the world suffer from major depression. Part of the problem is that mood and happiness are different for everyone. We're trying to understand those differences so we can better understand what happens in anxiety and depression. Do you want to help scientists uncover the secrets to happiness? The Happiness Project is a new mobile app where you can test your decision making and learn about the science of happiness. Be part of this unique scientific experiment and play games for science! Our goal is to develop mathematical equations that explain how humans make decisions, to describe the factors that determine feelings like happiness, and to understand the relationship between happiness and the decisions we make. By playing the games and completing the surveys in the app, you help us study the causes of happiness. This allows us to better understand how brain processes are linked to mental health problems like anxiety and depression, which may help to find new treatments.