The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (1994) identifies those with BPD as having:
A pervasive pattern of instability of interpersonal relationships, self-image, and affects, and marked impulsivity beginning by early adulthood and present in a variety of contexts, as indicated by five (or more) of the following:
It is called "Borderline" because at the time of conceptualization of BPD the symptoms patients exhibited were in between the borders of neurosis (mild mental illness) and psychosis (severe mental disorder where contact is lost with reality).
Often BPD doesn't stand alone. Suffers of BPD may suffer from elements of other personality disorders. This is due mainly to the fact that it is not possible to define an exact set of criteria for each personality disorder which will apply to all cases. Personality disorders are a relatively new field of research and it is likely the criteria used to define specific disorders will change over time.
Most sufferers diagnosed with BPD are women.
There are 3 main areas of concentration when looking at the causes of BPD:
Each of us is born with a temperament which in part determines how we react to life. Parents of multiple children can see differences between their offspring's character traits at an early age. There has been an increase into scientific research which shows that biological factors play a larger part in the development of personality than was once thought. Bockian states that "It is extremely unlikely that someone with a placid, passive, unengaged, aloof temperament would ever develop borderline personality disorder. To become labile and erratic demands that one have proclivities in that direction." (pg. 30)
He references a number of studies that show patients diagnosed with BPD had brains that tended to function differently to non-disordered subjects (pg. 32-33). The findings include reduced activity in the frontal lobes which relate to aggression and reduced or dormant activity in the prefrontal cortex on the right side (and several areas of the left side) of the brain relating to the regulation of impulsive behaviour. In addition one experiment found that the part of the brain that is critical for memory was "nearly 16% smaller in the borderline group".
The argument of nature versus nurture continues to be researched and at the moment the influence of environment and genetics appears to be at a 50/50 standpoint. Increasingly Psychologist aim to show that "negative" characteristics that appear from birth which are left unchecked or dealt with un-empathically can lead to problems later in life.
Borderlines usually come from traumatic backgrounds. It is not uncommon for them to have parents/family members who are alcoholics or abusers. Sometimes the abuser is not a parent but a close family member, friend or someone the child knows. The abuse may not even be directed at the child, they may witness abuse towards others within the home.
Whilst there are instances where Borderlines have been raised by loving parents Bockian states that "adults who have borderline personality disorder usually experienced some form of significant abuse, such as sexual or physical abuse, as a child. Incest and other forms of sexual abuse are particularly implicated." (pg.37).
The environment they grow up in is usually "invalidating" which means that the child is taught to believe that their feelings, thoughts and perceptions are not real or do not matter. The child learns to deny/cut off their real feelings leading to dissociation, splitting, low self-esteem, dependency and fear of abandonment, suicidal feelings and depression.
In these environments the boundaries are unclear. Physically their body may be abused, mentally their emotions may be tortured or ignored, materialistically they may not be provided for or stolen from e.g. a grandparent gives the child money for a birthday present and the parent uses it to buy drugs. Their privacy may be evaded; parents reading their diaries, listening in on telephone calls, watching them undress or bathe etc. As a result Borderlines usually have poor boundaries which can spill over to new relationships and jobs i.e. taking others boundaries for granted and allowing their own to be violated.
Generally the environment in which they are raised is un-empathic and the child's real needs are not met.
Society is becoming more and more narcissistic. People drive themselves to ensure their own needs are met and that they achieve a particular success or status in life.
Parents spend less time at home preferring/having to work long hours and when they come home they may be too tired to invest themselves in their children. They change their jobs more frequently perhaps even moving geographical location uprooting their children from their homes. The value of extended family has been eroded in order to make way for the change friendly nuclear family; while they are at work their children may no longer be cared for by family members who are emotionally connected. Marriage rates are declining and divorce rates are increasing, more children are growing up shuttling between their mum's house and their dad's house. Parents may opt to drink more, do drugs etc. to escape from the pressures of modern living. The decline in religion and changes in the law have made previously "prohibitive activities" more acceptable. All these changes are leading to an increase in unstable environments in which child development takes place.
In addition Bockian explains that "Television and other video media also have a profound impact on personality development. Role models and heroes have become increasingly violent, unstable and outwardly sexual. People who see more violence behave more violently. emotional shallowness and instability often dominate TV programs. Problems develop and are resolved in 30 to 60 minutes. The sincere expression of feelings and negotiations that compromise real conflict resolution doesn't happen on TV. as our children watch television they are learning how to be impulsive, cynical, sexually unrestrained, explosively angry and melodramatic - that is more borderline." (p.g. 41)