Mind, Brain, and Personality Disorders
Gabbard, Glen O.
Am J Psychiatry 162, no. 4 (2005)
648–55. doi:10.1176/appi.ajp.162.4.648

Introduction

Genes and environment are inextricably connected in shaping human behaviour. Experience shuts down the transcriptional function of some genes, while turning on that of others.

Psychosocial stressors have profound effects of a biological nature by changing the functioning of the brain.

Genes and environment

A genetic diathesis acted on by adverse environmental experience is necessary for the development of antisocial personality disorder.

Early psychotherapeutic interventions might serve to influence the expression of genes that lead to antisocial behaviour. Genes and environment are inextricably connected in the pathogenesis of antisocial behaviour.

The biological/psychosocial distinction, trauma, and borderline personality disorder

Early trauma is associated with greater symptoms of borderline personality disorder.

The hippocampus is vulnerable to the effects of stress, in part because it has many glucocorticoid receptors. Adult patients with borderline personality disorder have reduced hippocampal volume.

Early trauma may promote hemispheric lateralization and adversely affect integration of the right and left hemispheres. This may be reflected in the use of splitting as a major defence mechanism in borderline personality disorder.

A consequence of early childhood trauma is persistent sensitization of the hypothalamic-pituitary-adrenal (HPA) axis. This is related to hypersecretion of corticotropin releasing factor (CRF).

The hyperreactive physiological state is relevant to a subgroup of borderline personality disorder patients, but not all.

The role of psychotherapy: mentalization and theory of mind

The capacity to mentalize or have a theory of mind involves being able to recognize that someone else has a different mind from one’s own. Inherent in mentalization are an appreciation and recognition that the perceived state of one’s self and others are fallible and subjective and are representations of reality that reflect only one of a range of possible perspectives.

Mentalization refers to the capacity to represent mental states of the self and other.

Mentalization is created in the context of secure attachment with a caregiver who ascribes mental states to the child, treats the child as a mental agent, and helps the child to create internal working models.

Early childhood trauma leads to a defensive withdrawal from the mental world on the part of the victim.

Patients with borderline personality disorder often have great difficulty shifting form the psychic equivalence mode to the pretend mode, and this difficulty interferes with their capacity to recognize transference in psychotherapy.

One of the greatest challenges for a psychotherapist is managing the almost delusional conviction of some patients with borderline personality disorder that their perception is a direct reflection of reality rather than a representation of reality based on internal beliefs, feelings and past experiences.

Mentalization occurs on a continuum, and patients with borderline may learn to mentalize.

Patients with borderline personality disorder colonize the minds of others as a way of extruding and controlling perceived danger from within.

Mentalization entails several different brain structures working in concert. The medial frontal region is activated when people attribute mental states to others. The cerebellum was also activated. Mirror neurons in the premotor cortex also play a role.

Treatment implications

Patients with serious personality disorders respond to optimal dosages of selective serotonin reuptake inhibitors with improvements in anger, impulsive aggressive behaviour, and affective lability. It may also stimulate neurogenesis, particularly in the hippocampus and reduce the hyperreactivity of the HPA axis.

The reduction of HPA axis hyperresposiveness may affect the patient’s capacity to reflect. Splitting can also be tuned down because one doesn’t have to be as anxious as before.

Mentalization-based psychotherapeutic approach is helpful even after the therapy has ended.