A study recently appearing in the May 2007 issue of Journal of Psychiatry and Neuroscience reviews what we know about brain physiology of BPD patients.
What Is Borderline Personality Disorder?
According to the DSM-TR-IV (2000), psychology's diagnostic "bible," BPD is a type of psychological personality disorder that interferes with an individual's ability to regulate emotion.
People with this disorder are prone to unpredictable outbursts of anger, which sometimes manifests as self-injurious behavior. Borderlines are highly sensitive to rejection, and fear of abandonment may result in frantic efforts to avoid being left alone, such as suicide threats and attempts.
The Brain and BPD
Primarily over the past 30 years, researchers have examined the Borderline brain and found abnormalities in anatomy and physiological response.
In this study, Lis et al (2007) set out to examine existing research on the neurological differences between individuals with and without BPD as well as the genetics that may play a role in development of this disorder.
This Suite101 summary focuses on the metabolic differences that were found. For anatomical or biological differences, see Suite101 article Anatomy of the BPD Brain.
Study Methods
Using databases of academic articles, the investigators looked for relevant research published between 1980 and 2006 and found 49 journal articles describing original research about the brain and/or genetics of BPD patients.
BPD Research Findings
The use of neuroimaging in the study of BPD dates back only a few years. Overall, BPD has been linked to the amygdala and limbic systems of the brain, the centers that control emotion and, particularly, rage, fear and impulsive automatic reactions.
BPD Metabolic Abnormalities
Reduced Brain Metabolism
Neurological studies using positron emission tomography (PET) and magnetic resonance imaging (MRI) suggest that, in BPD patients, areas of the brain used to regulate and control emotion are hypometabolic (have reduced metabolic activity) and, in contrast, activation of limbic areas, when it occurs, is excessive (hypermetabolic).
This might reflect a failure of rational thought to control emotional thought, leading to the emotional instability that is characteristic of BPD.
NAA Concentrations
Patients with BPD also show deficiencies in N-acetyl-aspartate (NAA) concentrations in the dorsolateral prefrontal cortex, suggesting a lower density of neurons and disturbed neuronal metabolism.
NAA is the second most highly concentrated molecule in the brain. It’s made in the neurons, and although scientists are not certain as to its function, NAA is believed to be related to: fluid balance in the brain; lipid and myelin synthesis (myelin is the “insulation” that surrounds neural axons and enables efficient neuron-to-neuron communication); creation of N-Acetylaspartylglutamate; and perhaps in the production of energy in neuronal mitochondria.
Study Conclusions
Imaging technology such as PETs and MRIs have shown that brain structures with reduced volume in BPD patients may show hypermetabolism (increased metabolic activity).
Perhaps some of the lost volume in these structures may be due to reduced numbers of inhibitory neurons resulting in lost inhibition and ultimately the impulsive behavior and overly negative interpretation of others that is associated with BPD.
No comments:
Post a Comment