Correlation over causation. The study actually notes, “One plausible mechanism is the normalization of mental disorders through increased awareness and recepti

Correlation over causation. The study actually notes, “One plausible mechanism is the normalization of mental disorders through increased awareness and receptivity to diagnosis and treatment when having individuals with diagnosis in the same peer network.” Thus the study uses “transmission” in a specific technical sense of greater likely of diagnosis, not literally that you can catch a mental disorder from a peer where none existed before.