Borderline personality disorder (BPD) is characterized primarily by emotional dysregulation, extreme "black and white" thinking in some areas, and disrupted relationships. This instability often disrupts family and work life, long-term planning, and the individual's sense of self. The majority of those diagnosed with this disorder appear to have been individuals abused or traumatized during childhood. While less well-known than schizophrenia or bipolar disorder (manic-depression), BPD is more common, affecting two percent of adults, mostly young women. There is a high rate of self-injury without suicidal intent, as well as a significant rate of suicide attempts and completed suicide in severe cases. The suicide rate is approximately 8-10%. While a patient with depression or bipolar disorder typically endures the same mood for weeks, a person with BPD may experience intense bouts of depression, anxiety, or anger that may last only hours, or at most a day. These may be associated with episodes of self-injury (including cutting), impulsive aggression, and drug or alcohol abuse. Difficulties in cognition and sense of self can lead to frequent changes in long-term goals, career plans, jobs, friendships, and values. Although the causes of BPD are uncertain, environmental, genetic and epigenetic factors may play a role in predisposing patients to BPD symptoms and traits, possibly through the final common pathway of reduced central serotonergic neurotransmission. Possibly involved are serotonine, norepinephrine and acetylcholine, which are among the chemical messengers in circuits that play a role in the regulation of emotions, including sadness, anger, anxiety and irritability.
