Vulnerable populations with stigmatized conditions rarely seek help despite pressing need. Social campaigns aim to bridge this gap, yet their design involves a potential tradeoff: light-touch messages that diffuse easily may lack the depth to motivate behavioral change, while more complex and persuasive messages may resist peer-to-peer sharing. We formalize this tradeoff and test it in a randomized experiment promoting mental health care uptake among 1,993 Ukrainian refugees in Germany using a purpose-built bot on Telegram. We varied the messenger (celebrity endorsers vs. a peer patient), the message format (video or plain text), and whether peer-to-peer sharing was actively encouraged. Help-seeking was measured by calls to a mental health hotline. (Joint work with Alexandra Avdeenko, Luc Behaghel, Andreas Ette, Yagan Hazard, Alexander Moldavski, Andreas Meyer-Lindenberg, Nicolas Rüsch, and C. Katharina Spiess.)
