Gaslighting is an insidious form of manipulation and control, which derives its name from a 1938 play, Gas Light, and a film adaptation starring Ingrid Bergman. The victims of gaslighting are mislead and forced to doubt what they know to be true, even about themselves. Victims end up doubting their memory, perception, and sanity. Over time, the gaslighter’s manipulations grow more complex and potent, making it difficult for the victim to avoid. Gaslighting can occur in personal or professional relationships and gaslighters target their victims where it hurts: their sense of identity and self-worth.