Harvard Mental Health Letter

Borderline personality disorder: Origins and symptoms

One of the most complicated — and common — serious problems that confronts psychotherapists is a disorder characterized by consistent inconsistency (or stable instability) in mood, thinking, personal relationships, and self-image. About 2% of the general population and 15%–20% of patients in psychiatric hospitals suffer from borderline personality disorder.

The name has three parts, and all of them are important. Personality traits, according to the American Psychiatric Association's diagnostic manual (DSM-IV), are "enduring patterns of perceiving, relating to, and thinking about the environment and oneself that are exhibited in a wide range of social and personal contexts." Personality disorders are defined as stable, pervasive, and inflexible patterns of perception, thinking, and behavior that cause serious distress or disability. These patterns involve personal relationships, habits of thinking, and the control of impulses and emotions. People with personality disorders are difficult to live and work with and respond poorly to stress and change.


Borderline personality fits this description especially well. Its typical features are erratic moods, turbulent personal relationships, inability to control anger, and self-destructive behavior. People with borderline personality disorder are often chronically angry and quick to take offense. They become suddenly depressed, irritable, anxious, or enraged for reasons not obvious to others. They cannot tolerate solitude or keep company without constant conflict. They fear abandonment but repeatedly provoke it by plaguing others with unreasonable demands and complaints. They either vilify or extol others and even themselves — a habit that psychiatrists call splitting. Their intense attachments may be followed by sudden rejection. One person in the life of a borderline personality is a saint, another a monster, and these roles may be exchanged when the favored person does not fulfill impossible expectations.

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