When someone's experiences, especially their traumatic experiences, are belittled or dismissed by another person, it is often referred to as "gaslighting." Gaslighting is a form of psychological manipulation in which the abuser aims to make the victim doubt their perception, memory, or sanity. The term originates from the 1938 play and later movie called "Gas Light," in which a husband manipulates his wife into believing she is going insane by dimming the gas lights and then denying that the light level changed.
In the context you described, gaslighting occurs when a person who has experienced trauma shares their experiences, and the person responsible for causing the trauma denies or downplays the events, making the victim question their own memory or interpretation of what happened. This can be highly damaging to the victim's mental and emotional well-being, as it invalidates their feelings and experiences, leading to self-doubt and confusion.
Gaslighting is a form of emotional abuse and is often used as a means of maintaining power and control over the victim. It is essential to recognize gaslighting behaviors and seek support from trusted friends, family members, or mental health professionals if you or someone you know is experiencing this kind of manipulation.