Since the COVID-19 pandemic started, the number of young adults experiencing depression has increased. Most of them need help, but they are not aware that they have the symptoms of depression because they lack knowledge about depression. It is one of the reasons why the number of people with depression keeps escalating. Thus, this study aims to design and validate the design elements of an anti-depression mobile application named Happy Path. This mobile application is aimed at helping young adults handle negative emotions that may lead to depression. The most effective therapeutic approaches, Cognitive Behaviour Therapy and Beck Depression Inventory are adopted in Happy Path to deliver therapeutic content through the application. Thus, this paper describes the design and validation procedure for the anti-depression mobile application through the expert review method. After the experts evaluated the mobile application, several modifications were made based on their comments to improve the effectiveness of the application. Based on the findings of the expert review, it was found that the design of Happy Path is suitable for depressed people among young adults. The finalised prototype will be used in the future actual data collection.