"Mental illness is not contagious" actually only true before the invention of social media, a cognitohazard designed to give everyone each other's neuroses. It is astounding how many thoughts and behaviors that are highly in line with OCD, BPD, and so forth have become commonplace in people who otherwise do not have those conditions but they picked them up via social media exposure and the social dynamics of social media encouraging certain kinds of thoughts and behaviors.
A lot of my life's work of writing online can be understood as someone who recovered from BPD realizing how much of our queer/leftist/online communities function like we all collectively have BPD even if not every individual within that community would qualify on their own. When they act as a group, the group acts as though it has BPD.
Lately I am starting to realize that the same goes for OCD. Especially since 2020, OCD ways of thinking and behavior have become a social contagion spread online. Based on conversations I've had with friends with OCD, I don't think I have OCD or that I had it before I became a heavy social media user. But as my social life moved more and more online, and especially since 2020, I have developed some very OCD-like thought patterns and behaviors particularly around specific issues that are often the subject of intense heated online discourse. The reason I attribute these patterns to social media and not to just having had undiagnosed OCD my whole life is because these patterns only manifest around topics that are the frequent topic of heated discourse, and when I investigate the root fears, it is the fear of social repercussions above all else that manifests them.
Just because someone puts everything they think online in very strong language doesn't mean you need to accept those thoughts and patterns into your own brain.