Rather than focus purely on the group dynamic, I encourage people to read Madness by Justin Garson. It’s an exploration of the neuroprotective aspects of mental illness, the biological reasons why people cling to false hope or pursue delusions.
Considering the research that has been done by psychologists employed by the US disinformation systems producing narratives like QAnon and Russiagate, I assume these tricks are already known quantities being exploited. That’s just my read though, Garson never brings up anything like that.