Narcissism is a concept in psychoanalytic theory, which was popularly introduced in Sigmund Freud's essay On Narcissism (1914).
People who have dependent personality disorder are likely to demonstrate a distinct fear of separation (from a partner or caregiver) to the extent that if a relationship ends, they almost instantly try to find another one to fill the void.
People with BPD often engage in idealization and devaluation of themselves and of others, alternating between high positive regard and heavy disappointment or dislike.
Self-harm and suicidal behavior are common and may require inpatient psychiatric care.
Recent research suggests that the disorder, which afflicts 2% of the population, is linked to hormone levels and can be exacerbated by hormonal treatment such as birth control.
From Wikipedia: Borderline personality disorder (BPD) is a personality disorder characterized by unusual variability and depth of moods.