Digital technology has a great potential to support mental health and wellbeing. It has many benefits over face-to-face treatment, including higher cost-effectiveness, wider reach and reduced support-seeking barriers, however, it is often impeded by high levels of dropout and non-usage attrition. My research aims to evaluate the effectiveness of digital mental health and wellbeing support. Specifically, I will aim to understand strengths and weaknesses of mental health and wellbeing support; how and for whom digital mental health and wellbeing support is effective; and understand engagement with mental health and wellbeing support in a target autistic population.