Gaslight is a movie from the 1940's with Ingrid Bergman, her husband tries to convince her that she's slowly losing her mind.
Story revolves around the Ingrid Bergman [Paula] marrying Charles Boyer. He only married her to be close enough to search for Paula's aunts jewels. Interestingly, the husband had killed the aunt, years earlier, to facilitate stealing the jewels. His plan had failed. But not he is married to the niece and somewhere in the house are the jewels. He disappears at night and makes his way into the attic through the roof. When he turns on the gaslight, no electricity in the era of the films story, the lights dim in the rooms below. Paula mentions this to her husband and he says she is imagining things. The mind manipulation continues throughout the movie until he is exposed by a policeman [ Joseph Cotton]. Excellent acting by all.
Now, a creative mind could see how many of the moves of the Watchtower is similar to gaslighting. Making statements that later are changed. Doctrines that are rigidly taught only to be cast aside and treated as apostate lies later. A thinking person would imagine that they are loosing their minds if they took seriously everything the Society has said in its short history.