Using social media for the purpose of disseminating mental health information is a critical area of scientific inquiry for health communication professionals. The purpose of this study was to investigate whether the presence of a first-person testimonial in educational mental health information placed in Facebook and Twitter messages influenced college students’ (N = 257) source perceptions, information processing, cognitive elaboration, health information recall, beliefs, and behavioral intentions. Results show that exposure to social media messages that featured mental health information embedded with a testimonial predicted less source homophily and more critical thoughts about the social media source, less systematic message processing, and less cognitive elaboration. Health information recall was significantly impacted by both the social media platform and message content such that participants in the testimonial condition on Facebook were more likely to recall the health facts in those messages whereas participants who viewed the testimonial in Twitter were less likely to recall the facts in those tweets. Compared to those who read Facebook messages, participants who read Twitter messages reported higher levels of systematic message processing. These findings suggest that the integration of health testimonials into social media messages might inadvertently provoke psychological resistance to mental health information, thereby reducing the persuasive impact of those messages. [ABSTRACT FROM PUBLISHER]