The Research Diary CoAct for Mental Health (Quadern de Recerca CoActuem per la Salut Mental) is a publication associated with the project “CoAct for Mental Health”, in the frame of the CoAct project, that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement Nº 873048. CoAct for Mental Health focuses on Mental Health Care and social support networks. Social support networks refer to people's social environment, which is generated informally, not professionally. This research considers people with an experience in mental health as experts in the field in this matter. The research outcomes should be scientifically valuable but also should contribute to empower the mental health community. The main actors of the research are Co-Researchers (CoRes). They are persons with self-experience in mental health and relatives, acting as experts in the field. They have co-designed a collective research tool in the form of a Telegram chatbot. The collective digital conversation content, namely microstories, are built through co-creation mechanisms that allow to reach consensus and agreement among participants while including different perspectives and viewpoints. This Research Diary, that was tailor-made for CoAct for Mental Health, was ideated to guide the CoRes during the process of microstories co-creation. It has been proved to serve as a useful bridge between the online co-creation sessions, done in pandemic times and the CoRes’ offline individual work on writing down microstories related to their personal experiences. The Research Diary was physically delivered at the CoRes’ homes during the COVID pandemic and has encouraged and guided their offline work thus allowing to keep a more continuous relationship with the project. It combines both detailed information about the project and practical to-be-filled cards.