I've had periods of my life where I could have related heavily.

For me, it turned out to be the case that in general (and pretty much since childhood) I felt like I had no control over very important things. Things like my safety, the safety of loved ones, my body, etc.

But shifting my focus to the world at large was much less personal and much less triggering. It also (in my mind) brought everyone else on earth into the fold with me, I wasn't alone in my lack of control and empowerment, we were all in it together. So not only was it less personal and less triggering, but it was also much less lonely (in that demented, self-soothing sort of way).

When I finally traced it all back in therapy, there turned out to be obvious connections most of the time.

(Possible Triggering Content)

While being sexually abused as a young teenager, I did not focus on it very much. Instead I focused on all of the sex slave trade worldwide, with constant intrusive thoughts about it, as well as all of the violence in general in the world. It constantly filled my mind and filled me with despair. But in truth it was a coping mechanism, because it was less personal and also took me from feeling like an isolated victim to being in a big family of victims across the world.

(End Possible Trigger)

Other times it was much more vague and metaphorical. Fears of my biological father gradually morphed by adulthood into paranoid fears about government conspiracies. We were all going to be rounded up in FEMA camps and executed. My real-life issues even flavored my paranoid psychosis episodes, with themes of all-powerful authority figures hellbent on hurting and controlling us all.

Some (not all, but some) of this went away after I made some progress in therapy.

I believe that for many people, any situations that create feelings of helplessness, doom and no control, can cause such metaphorical intrusive thoughts. Certainly mental illness can cause all three of those feelings on a regular basis, too.