Abstract Social capital indicative of community interaction and support is intrinsically linked to mentalhealth. Increasingonlinepresenceisnowthenorm.Whilstsocialcapitalanditsimpact on social networks has been examined, its underlying connection to emotional response such as mood, has not been investigated. This paper studies this phenomena, revisiting the concept of “online social capital” in social media communities using measurable aspectsofsocialparticipationandsocialsupport.