The widespread use of the internet is transforming the delivery health information and communication. In particular, the inherent socio-technical attributes of computer-mediated communication (CMC), such as online open forums, chat rooms and blogs provide a novel opportunity for offering personalized health information and social support. However, to date, little research has been carried out to assess this context and this paper is aimed at addressing this lacuna, thereby providing clearer understanding of this complicated phenomenon and its intrinsic elements. To achieve this, we conducted a case study in an online open forum composed of a number of chat rooms used for communication about health issues, mainly depression. Our early analysis has revealed that participants (i.e. healthcare professionals, web instructors and users) take on different roles in order to ensure that the online forum functions in a lively and sustainable manner.