Neurolinguistics and hypnosis has been using this since the 70's. They use the term anchor. Anything can become an anchor for emotional state. And there are techniques to "program" anchors into the brain.

Sadly the mental health sciences didn't pay as much attention to NLP as salespeople and advertisers did. So it became a force for manipulation alongside NLP practitioners using it purely to help people.

Yes it is a dangerous and double-edged sword. Luckily though, awareness of it is also a remedy for it. Anchors can be neutralized or reprogrammed.

So if you ever run across an evil hearted monster who anchors nightmares into your brain, find a reputable NLP coach to help you undo it.