What most people don't know is that the term gaslighting has been around for much longer than 10 years, and its meaning has changed a great deal in that time. Despite MGM's efforts, the 1940 film survives. The first use of the term gaslighting as a clinical term was in 1969, in the Lancet. Upon his release, his wife insisted that his symptoms had worsened and he "belonged in a mental hospital". Just as our approach to mental health has changed over the years, so has the usage of the term gaslighting.