This is a nice and useful explanation of: Gaslighting, a form of psychological abuse.

It was mentioned by one of the commenters regarding tactics of psychological abuse that homosexuals use against their heterosexual spouses.

(from wiki) It uses persistent denials of fact which, as they build up over time, make the victim progressively anxious, confused, and less able to trust his or her own memory and perception. A variation of gaslighting, used as a form of harassment, is to subtly alter aspects of a victim’s environment, thereby upsetting his or her peace of mind, sense of security, etc.

Gaslighting is a common tactic/symptom of some mental disorders such as Borderline Personality Disorder (BPD) and Narcissistic Personality Disorder (NPD), and other Personality Disorders. People having BPD will use gaslighting (conciously or unconciously) along with a wide variety of psychologically manipulative/abusive tactics to fend-off criticism of their own actions that they deem too painful to accept responsibility for. (See Denial). However, there are a variety of reasons, other than gaslighting, why people suffering with these disorders may make untrue statements (and authentically believe them to be true) such as confabulation and dissociation. These reasons are not considered gaslighting by virtue of their not being intentional.

Cultural connections

The term was coined from the 1940 film Gaslight and its 1944 remake in which changes in gas light levels are experienced several times by the main character. The classic example in the film is the character Gregory using the gas lamps in the attic, causing the rest of the lamps in the house to dim slightly; when Paula comments on the lights’ dimming, she is told she is imagining things. Paula believes herself alone in the house when the dimming occurs, unaware that Gregory has entered the attic from the house next door, and is searching for jewels he believes to be hidden there. The sinister interpretation of the change in light levels is part of a larger pattern of deception to which the character Paula is subjected.