Invalidating environments may include contexts where a childs emotions and needs are neglected, ridiculed, dismissed, or discouraged, or may include contexts of trauma and abuse. Linehans theory was modified by Sheila Crowell, who proposed that impulsivity also plays an important role in the development of BPD. Crowell found that children who are emotionally vulnerable and are exposed to invalidating environments are much more likely to develop BPD if they are also highly impulsive. Both theories describe an interplay between a childs inherited personality traits and their environment. For example, an emotionally sensitive or impulsive child may be difficult to parent, exacerbating the invalidating environment; conversely, invalidation can make an emotionally sensitive child more reactive and distressed. Diagnosis
Diagnosis of borderline personality disorder is based on a clinical assessment by a mental health professional. The best method is to present the criteria of the disorder to a person and to ask them if they feel that these characteristics accurately describe them. Actively involving people with BPD in determining their diagnosis can help them become more willing to accept it. Some clinicians prefer not to tell people with BPD what their diagnosis is, either from concern about the stigma attached to this condition or because BPD used to be considered untreatable; it is usually helpful for the person with BPD to know their diagnosis.
These two neural networks are seen to be dysfunctionally operative in the limbic system, but the specific regions vary widely in individuals, which calls for the analysis of more neuroimaging studies.Also (contrary to the results of earlier studies) those with BPD showed less activation in the amygdala in situations of increased negative emotionality than the control group. John Krystal, editor of the journal Biological Psychiatry, wrote that these results "[added] to the impression that people with borderline personality disorder are set-up by their brains to have stormy emotional lives, although not necessarily unhappy or unproductive lives". Their emotional instability has been found to correlate with differences in several brain regions. Mediating and moderating factors
Executive function
While high rejection sensitivity is associated with stronger symptoms of borderline personality disorder, executive function appears to mediate the relationship between rejection sensitivity and BPD symptoms. That is, a group of cognitive processes that include planning, working memory, attention, and problem-solving might be the mechanism through which rejection sensitivity impacts BPD symptoms. A 2008 study found that the relationship between a persons rejection sensitivity and BPD symptoms was stronger when executive function was lower and that the relationship was weaker when executive function was higher. This suggests that high executive function might help protect people with high rejection sensitivity against symptoms of BPD. A 2012 study found that problems in working memory might contribute to greater impulsivity in people with BPD. Family environment
Family environment mediates the effect of child sexual abuse on the development of BPD.