Review Question - QID 103736

This patient has a history of unstable relationships, dependence on relationships, and acts of self-harm (scars on her wrists) suggesting a diagnosis of borderline personality disorder. Borderline personality disorder most commonly utilizes the defense mechanism of splitting.

Splitting is a common phenomenon in borderline patients and manifests itself as viewing others as either all good or all bad, both of which are unsubstantiated given the amount of positive or negative influence that the person has on the patient's life. An example may be a patient stating a doctor is the best physician when the physician tends to the patient's needs, but then suddenly switches to hating the physician when the physician refuses something the patient wants. Borderline personality disorder presents with a history of unstable and volatile relationships, an unstable mood, and acts of self-harm. Treatment involves dialectical behavior therapy (DBT) and mood stabilizers (such as lithium).

Incorrect Answers:
Answer 1: Displacement is the process whereby negative ideas or feelings are transferred to some neutral person or object such as a man hitting his pet because his wife left him. This is not the most common defense mechanism seen in borderline personality disorder.

Answer 2: Identification is the modeling of behavior after someone who is more powerful. This may be a student who dresses or picks up mannerisms of a professor whom they respect. It is not common in borderline personality disorder.

Answer 3: Projection is the unconscious expulsion of an unacceptable emotion or thought onto an external source. An example would be a man who is actually upset at his wife accusing her of being mad at him.

Answer 5: Sublimation is the conversion of unacceptable impulses into socially acceptable outlets. An example might be an aggressive individual taking up boxing, or, as in this patient, a sad person writing music. The question asked for the most common defense mechanism exhibited by this patient's underlying diagnosis which would be splitting in borderline personality disorder.

Bullet Summary:
Borderline personality disorder presents with an unstable affect, mood swings, unstable relationships, and self-harming behavior and splitting is a common defense mechanism.