[ame="http://en.wikipedia.org/wiki/Borderline_personality_disorder"]Wikipedia link[/ame]
Some excerpts:
"The disorder typically involves unusual levels of instability in mood; "black and white" thinking, or splitting; chaotic and unstable interpersonal relationships, self-image, identity, and behavior; as well as a disturbance in the individual's sense of self. In extreme cases, this disturbance in the sense of self can lead to periods of dissociation."
"Individuals with BPD can be very sensitive to the way others treat them, reacting strongly to perceived criticism or hurtfulness. Their feelings about others often shift from positive to negative, generally after a disappointment or perceived threat of losing someone. Self-image can also change rapidly from extremely positive to extremely negative. Impulsive behaviors are common, including alcohol or drug abuse, unsafe sex, gambling and recklessness in general.
Attachment studies suggest individuals with BPD, while being high in intimacy- or novelty-seeking, can be hyper-alert to signs of rejection or not being valued and tend toward insecure, avoidant or ambivalent, or fearfully preoccupied patterns in relationships. They tend to view the world generally as dangerous and malevolent, and themselves as powerless, vulnerable, unacceptable and unsure in self-identity.
Individuals with BPD are often described, including by some mental health professionals (and in the DSM-IV), as deliberately manipulative or difficult, but analysis and findings generally trace behaviors to inner pain and turmoil, powerlessness and defensive reactions, or limited coping and communication skills."
DSM-IV-TR diagnostic criteria:
BPD is indicated by five (or more) of the following:
1. Frantic efforts to avoid real or imagined abandonment. (Note: Do not include suicidal or self-injuring behavior covered in Criterion 5)
2. A pattern of unstable and intense interpersonal relationships characterized by alternating between extremes of idealization and devaluation.
3. Identity disturbance: markedly and persistently unstable self-image or sense of self.
4. Impulsivity in at least two areas that are potentially self-damaging (e.g., promiscuous sex, eating disorders, binge eating, substance abuse, reckless driving). (Note: Do not include suicidal or self-injuring behavior covered in Criterion 5)
5. Recurrent suicidal behavior, gestures, threats or self-injuring behavior such as cutting, interfering with the healing of scars (excoriation) or picking at oneself.
6. Affective instability due to a marked reactivity of mood (e.g., intense episodic dysphoria, irritability or anxiety usually lasting a few hours and only rarely more than a few days).
7. Chronic feelings of emptiness
8. Inappropriate anger or difficulty controlling anger (e.g., frequent displays of temper, constant anger, recurrent physical fights).
9. Transient, stress-related paranoid ideation, delusions or severe dissociative symptoms