EXPRESS: Are You Okay? Effects of a National Peer-Support Campaign on Mental Health

National public health awareness campaigns that emphasize peer-to-peer support are increasingly adopted, but evidence on the effects of peer-based programs at scale remains limited. Using quasi-experimental methods, we examine whether the prominent nationwide “R U OK? Day” campaign affects short-term mental health outcomes in Australia. Leveraging survey and administrative data, we find R U OK? Day leads to a 4% of a standard deviation increase in self-reported mental wellbeing, with the effect particularly pronounced among middle-aged males who experience a 9% of a standard deviation increase. We find no detectable effects on mental health care utilization, and we detect no statistically significant changes in suicide-related deaths in the short run, though the mortality outcomes are rare and power is limited. Our results underscore that peer-based campaigns can improve mental wellbeing, especially for high-risk groups, and point to a distinction between short-run psychological responses and outcomes that require behavioural follow-through.