8 Process evaluation To understand the perception and effectiveness of the social networking services, all the participants in the intervention group will also be invited to give feedback through the social networking platform. Furthermore, six participants from the intervention group will be selected (3 relapsers and 3 non-relapsers) to participate in an in-depth interview after the 3-month follow-up. Questions such as their satisfaction, perceptions on the advantages and disadvantages of the intervention, and any other suggestions for improvement will be explored and discussed.