This experiment examined how two language features-linguistic agency and assignment of causality-of online support-seekers' messages regarding depression influenced viewers' perceived stigma and features of their support messages. Participants (N = 254) read and responded to an online support-seeking post about depression. Our results revealed that personal stigma toward a depressed individual was lower when the individual disclosed a biological cause for the depression and assigned agency to depression than agency to human. Additionally, when agency was assigned to depression with a biological rather than non-biological cause, more positive emotion words were utilized in participants' response posts. Cognitive process words were used more often in response to messages with non-biological causality than biological causality.