I wrote my Master's thesis with the title "Mood Effects of Immersion, Control, and Interaction in Virtual Reality Eye-Movement Desensitization and Reprocessing Therapy" on a therapeutic VR app aimed at reducing symptoms of PTSD. For this project I first researched the user needs and dilemmas they're facing when using the application. I then designed a 2D mock-up of a future version addressing these issues and then developed a 3D VR prototype. In the design I focused on introducing immersive and interactive elements to the existing product in order to enhance user experience and make the experience more human-centred. I validated the prototype with user interviews and confirmed a greater decrease in unpleasant moods compared to the earlier version, suggesting that the new design was impactful in improving the users' mood.