In the essay “Lies and Their Deception” in the same book, Lying, Cheating, and Carrying On, Clarence Watson, JD, MD pulls no punches when he says, (p. 98):
Given that a BPD hallmark is interpersonal relationships that alternate between idealization and devaluation, the person with BPD may distort facts aimed at the person with whom they desire a personal relationship.
Whether through attempts to draw persons into [intense and rocky interpersonal] relationships or viscously attack another during episodes of the extreme rage associated with perceived abandonment-the borderline personality may use lies and deceitfulness to accomplish these objectives.
Impulsivity and poor impulse control, he writes, means they may not consider the impact of their words before they speak. “In the moment, their desired objective, whatever that may be, takes such precedence over speaking the truth or behaving honestly that the potential consequences of their conduct are reduced to shadowy details.”