Gaslighting: Know It and Identify It to Protect Yourself | Psychology Today

By telling you that everyone else (your family, the media) is a liar, it again makes you question your reality. You’ve never known someone with the audacity to do this, so they must be telling the truth, right? No. It’s a manipulation technique. It makes people turn to the gaslighter for the “correct” information—which isn’t correct information at all.

Well worth the real, useful in many situations… 

https://www.psychologytoday.com/blog/here-there-and-everywhere/201701/gaslighting-know-it-and-identify-it-protect-yourself