Mental health articles

Borderline personality disorder causes as follows:

Biological factors

There have been relatively few studies of the family/genetic infl uences on borderline personality disorders. However, a number are now emerging. Distel et al., for example, studied a total of 3644 twins aged between 18 and 86 years across the Netherlands, Belgium, and Australia. They estimated 42 per cent of the variation in borderline personality features was attributable to genetic factors, with similar levels of heritability across all three countries. These fi ndings compare with the 35 per cent variance of traits explained by genetic factors in a Norwegian cohort. Any genetic process is still far from clear, however, and likely to be polygenic. Distel et al., for example, are even now considering ‘candidate’ genes for the condition, while work by Tadic´ et al. suggests the possibility that the condition may involve interactions between genes controlling both dopaminergic and noradrenergic systems. Other studies have investigated neural and neurochemical mediators of the condition. In one such study, Tebartz van Elst et al. found that the hippocampi of people with borderline personality disorder were 20 per cent smaller than those of a ‘normal’ comparison group, while their amygdalas were 24 per cent smaller. There is also evidence of damaged or poorly functioning frontal cortices, which may be related to the dysregulation of serotonin within this brain area. This may contribute to a lack of inhibition in the regulation of aggression. Reports of the effectiveness of antipsychotic medication in the treatment of at least some cases of borderline personality disorder suggest that low levels of dopamine may also be implicated in its presentation – a finding consistent with the fi ndings of Tadic´ et al. above. A very different view on possible biological mechanisms in borderline personality stems from work on a hormone and neurotransmitter called oxytocin. This is perhaps best known for its role in birth and breastfeeding. However, there is also increasing evidence that within brain structures including the amygdale, hypothalamus, oxytocin is involved in empathy and social bonding. Not only may oxytocin encourage socially positive behaviour, it may enhance encoding and conceptual recognition of positive social stimuli over social-threat stimuli.

Socio-cultural factors

Risk for personality disorder is increased by a number of social factors. People with borderline personality are more likely than the general population to have been neglected by their parents,to have had multiple caregivers and to have experienced parental divorce, death or signifi cant childhood trauma such as sexual abuse or incest. In one study of this phenomenon, Bandelow et al. found that people with borderline personality disorder reported much higher levels of traumatic childhood experiences such as sexual abuse, violence, separation from parents, childhood illness and other factors than a matched, ‘normal’ comparison group.

Psychological processes

Psychological processes translate the social factors considered above into individual experiences. One significant outcome may be poor attachment and bonding with parents – both of which may contribute to the development of borderline personality disorder. Of interest in relation to these fi ndings are those of Zweig-Frank and Paris  who followed a cohort of people diagnosed with borderline personality disorder for 27 years and found that while reports of parenting quality and childhood abuse or trauma did not predict the long-term outcome of the condition, a measure of parental bonding did. From a psychoanalytic viewpoint, object relations theorists suggest that as a result of negative childhood experiences, the individual develops a weak ego and needs constant reassuring. They frequently engage in a defence mechanism known as splitting, dichotomizing objects into ‘all good’ or ‘all bad’ objects, and fail to integrate the positive and negative aspects of self or other people into a whole. This inability to make sense of contradictory elements of self or others causes extreme diffi culty in regulating emotions as the world is constantly viewed as either ‘perfect’ or ‘disastrous’. Cognitive theoristsargue that negative childhood experiences translate into maladaptive schemata about self-identity and relationships with others. These include beliefs that ‘I am bad’, leading to self-punishment; ‘No one will ever love me’, leading to avoidance of closeness; and ‘I cannot cope on my own’, leading to over-dependence. Selfharm may be maintained by operant processes: successful control of other people’s behaviour by threats of self-harm reinforces its use as a means of coping. Strong negative emotions experienced as a consequence of catastrophic or other negative beliefs may also lead to episodes of self-harm. Many people with borderline personality feel numbness or dissociation immediately before or while they harm themselves. Self-harm may therefore provide a means of escape from unbearable emotions, and may not be accompanied with feelings of physical pain. Other people, who feel confused and out of control, may fi nd any pain they experience a form of self-validation of their own status and self-identity. According to the cognitive model, the use of self-harm to avoid emotional pain or to manipulate others is indicative of high levels of interpersonal anxiety, low self-esteem and a lack of alternative coping strategies to deal with personal stress. Cognitive processing defi cits may also underpin some of the traits of borderline personality. Sala et al., for example, noted that hippocampal and frontal cortex deficiencies may be related to poor memory control. To investigate this phenomenon, they exploring the capacity of people with borderline personality to fi rst learn and then to inhibit memories of various word pairs, and found both processes to be impaired. They took this to indicate that people with borderline personality disorder may be less able than others to inhibit the emergence of unwanted memories and dissociative symptoms. In another cognitive defi cit model of the condition, Wupperman et al. correlated measures of mindfulness with core features of borderline personality disorder including interpersonal problem-solving abilities, and impulsive and passive emotion-regulation strategies in a sample of young adults. They found that defi cits in mindfulness were linked to diffi culties in attention, awareness and discrimination between ‘internal and external experience’, factors that they saw as central to the disorder. Finally, Dyck et al. reported that people with borderline personality disorder experienced difficulty in the immediate discrimination of both neutral and negative emotional expressions – again, factors likely to result in the underlying difficulties in social interaction central to the disorder.

Tags: borderline personality disorder, causes, disorder, personality