What are the biological influences in borderline personality disorder?

Answer 1

There are abnormal brain structures in this disorder,smaller amygdala & hyppocampus as much as 16% (this could be a why BPDs can have memory & emotional problems)

this study talks about areas of the brain that could lead to impulsivity in BPDs. http://europepmc.org/abstract/MED/22407235

The brain & genes are related as

eg. A certain variation of the gene (allele) that is involved in the making the brain chemical serotonin(neurotransmitter) is associated with more suicide attempts in people with this gene than those who do not have this gene.

BPD suffers who have a certain dopamine gene tend to be more depressed than those who don't have this gene.Another gene is more common in people who self harm.

Parts of the prefrontal cortex including the anterior cingulate are

areas of the brain that put the break on emotional responses. These areas are much less active in BPDs than in normal people,so BPDs don't have the automatic control of emotions that other people without the condition have. Adding to the problem the *amygdala is hyperactive and the system that would help decrease this activation doesn't work as much slowing down the reaction, so the BPD feels things very strongly & for longer.(Don't forget that these areas of the brain have neurotransmitters in them which are made by genes.)

*The amygdala is in charge of regulating the expression of emotions,especially the expression of "fear, rage, and automatic reactions (such as cutting) when it is hyperactive a person gets moody & has a roller coaster of rapidly changing emotions.

The level of heritability for BPD is estimated to be 52-68%.This is about the same as for bipolar.

What is believed to be inherited are the temperaments for affective dysregulation (strong mood swings),impulsivity and interpersonal hypersensitivity (being too sensitive when in relationships),not the full disorder.

source-http://www.borderlinepersonalitydisorder.com/understading-bpd/a-bpd-brief/

Genetic material on chromosome 9 was linked to BPD traits.

There was no significant difference in heritability rates between men & women.It would seem that young adults have more BPD features than adults.

I will be writing more on it on my blog

reducingourmentalillnesses1atatime.blogspot.com

I hope you understand this issue better now =)

Read more: Is_borderline_personality_disorder_genetic