Characterized by: instability of mood, poor self-esteem and self-image, and poor impulse control (1). These mood fluctuations may occur over the space of hours or days, as opposed to the mood fluctuations that occur in bipolar affective disorder. There is often a great fear of abandonment, and higher sensitivity to rejection (or perceived rejection). This can manifest as more unstable interpersonal relationships. The term “splitting” refers to these intense by transient relationships, which can suddenly switch from idealization to contempt.


A person with borderline personality disorder can be incredibly charismatic and witty and enjoyable to be around. Beware of the patient who is overly effusive regarding your abilities. It can be a sign of splitting.

In the doctor-patient relationship splitting can be very problematic, as miscommunication is more like to occur in this setting. Team communication even to the point of regular case meetings, becomes even more important when “splitting” is occurring.

Patients with borderline personality disorder certainly have a higher rate of self-harm without suicidal intent, and in addition a higher rate of suicide attempts (unfortunately sometimes successful).

Epidemiologically borderline personality disorder is much more common in women (ratio of 4:1), and there is often a history of childhood trauma. It is difficult to make a diagnosis of borderline personality disorder prior to the age of 18 years, due to the other developmental changes occurring at this time. It is also extremely uncommon for a first diagnosis of borderline personality disorder after the age of 40 years. This may reflect the evolution of borderline personality disorder into more stable personality disorders, or it may mean that patients with borderline personality disorder may stop seeking help as they age.