Gaslighting is a form of psychological abuse where a person or group makes someone question their sanity, perception of reality, or memories. People experiencing gaslighting often feel confused, anxious, and unable to trust themselves. The term gaslighting derives from the 1938 play and 1944 film Gaslight, in which a husband manipulates his wife into thinking she has a mental illness by dimming their gas-fueled lights and telling her she is hallucinating.