Kristen DiMera is portrayed by Eileen Davidson. Kristen and her brother Peter were raised but not legally adopted by super villain Stefano DiMera at a very young age following the deaths of their parents; however, their mother Rachel was later revealed to be alive.
Kristen and her brother Peter were adopted by Stefano after their father died. Kristen had strong feelings for John Black, but these feelings were complicated by Stefano's wish for her to marry Tony. Kristena started out as good person, but her rivalry with Marlena Evans for John, eventually caused her to become violent and manipulative. Kristen's reign of terror ended when she was tricked into becoming a part of a Slave trade.
In 2012, Stefano brought Kristen back to Salem to help bring the DiMera family together. Kristen got involved with Brady Black as a way to get back as John and Marlena, and later raped Marlena's son, Eric Brady, to get back at her. After being exposed, Kristen tried to flee town, but crashed her car and went missing. In 2013, Kristen returned to Salem just long enough to steal Brady's child with Theresa Donovan and raise him as Christoper DiMera. Melanie Jonas ultimately realized what Kristen had done, and helped reunite the baby with his real parents, while Kristens fell through a window during a scuffle with Marlena Evans and is presumed dead.
Kristen DiMera is known to have a complex personality, one which according to psychiatrist Dr. Marlena Evans is a disordered personality. Based on her long-term behavior patterns, Kristen is afflicted with borderline personality disorder. Borderline personalities are known to be extremely impulsive, master manipulators and pathological liars. They are also known to be emotionally unstable and to have very intense and unstable interpersonal relationships, to intensely hate and fear any type of abandonment or rejection, borderlines also have a distorted self-image or an identity disturbance and are prone to intense temper tantrums Other common traits and/or behaviors which those with BPD usually engage in include intimidation and threat making (where the borderline may give inappropriate, intentional warnings of destructive actions or consequences), pathological narcissism, thought policing (a process of interrogation or attempt to control another individual's thoughts or feelings), lack of empathy, lack of conscience and callousness, lack of boundaries, hypervigilance, intense anger and rage, stalking, a sense of entitlement, denial, inappropriate sexually seductive or sexually provocative behaviour, blame shifting, passive-aggression, psychological projection, controlling, vanity, intense jealousy, and envy.