The first study of Trigger Warnings did not come out favorably. They undermined emotional resilience and increase anxiety toward the material being warned against.
It should be noted that the effect of trigger warnings could only be had on people who stayed past the warning. I always thought (and maybe I'm wrong) a rationale for trigger warnings were for people who might be triggered to leave the room. Presumably, those people would have avoided emotional hardship. But the study has nothing to say about them.
It is also worth mentioning that the sample sizes were pretty small (couple hundred) and of course, this is only one study.
Given that trigger warnings are the exact opposite of Exposure Therapy, we may want to do some longer term studies on the effects of trigger warnings. Do triggered people end up more fragile if they don't face their fears in at least small doses?
Also see Economist Bryan Caplan disagree with secret genius blogger Scott Alexander on trigger warnings.
