"Gaslighting is a term often used by mental health professionals (I am not one) to describe manipulative behavior used to confuse people into thinking their reactions are so far off base that they're crazy." ... "Those who engage in gaslighting create a reaction -- whether it's anger, frustration, sadness -- in the person they are dealing with. Then, when that person reacts, the gaslighter makes them feel uncomfortable and insecure by behaving as if their feelings aren't rational or normal."

via Huff Po