Mind-Brain Dichotomy Irrelevant In Personality Disorders, Gabbard Says

Accumulating evidence points to the interaction of genetic and environmental influences in the etiology of personality disorders, according to Glen Gabbard, M.D.

In a lecture at APA's 2004 annual meeting in May, Gabbard discussed research on antisocial and borderline personality disorders suggesting that long-held distinctions between mind and brain or between genes and environment are no longer relevant.

“Personality disorders are best understood and treated without using either-or dichotomies of brain and mind,” he stated.“ Environmental influences on gene expression make nature-nurture distinctions difficult, and psychosocial factors produce biological changes in the brain. Medication and therapy work synergistically to make changes in the brain over time. And the language of the mind is necessary for psychotherapy, but we must recognize that its effect is on the brain.”

Gabbard is the Brown Foundation Chair of Psychoanalysis and a professor of psychiatry at Baylor College of Medicine in Houston. He is also a training and supervising analyst at the Houston-Galveston Psychoanalytic Institute.

Genes Modify Experience

In a long-term follow-up study, research by Avshalom Caspi, Ph.D., and colleagues published in the August 2, 2002, Science found an association between gene-environment interaction and development of antisocial personality disorder. In particular, the research implicates the monoamine oxidase A (MAOA) gene, which encodes the enzyme that metabolizes norepinephrine, serotonin, and dopamine, Gabbard explained.

Eight percent of 1,037 children born in Dunedin, New Zealand, were serially assessed up to age 26, with 96 percent of the cohort still intact at age 26. Between the ages of 3 and 11 years, 8 percent experienced “severe” maltreatment, 28 percent experienced “probable” maltreatment, and 64 percent experienced no maltreatment.

Four sources of information were fit together using a common-factor model to derive a score for antisocial behavior. The four sources were evidence of conduct disorder using criteria from DSM-IV, convictions for violent crimes identified via the Australian and New Zealand police, a personality disposition toward violence measured as part of a psychological assessment at age 26, and symptoms of antisocial personality disorder ascertained at age 26 by collecting information about the study members from people they nominated as “someone who knows you well.”

Gabbard reported that males in the cohort who had low expression of MAOA activity and who experienced childhood abuse also had high antisocial scores, while males with high MAOA activity did not have high antisocial scores even if they had experienced maltreatment.

“The researchers concluded that there must be a functional polymorphism in the MAOA gene that moderates the impact of early childhood maltreatment on the development of antisocial behavior,” he said.

Gabbard also reviewed the findings of primate researcher S.J. Soumi, who identified a group of “cluster B” rhesus monkeys that displayed the characteristics of borderline and antisocial personality: the monkeys were impulsive and overtly aggressive, harassed younger monkeys, challenged dominant males, and made ill-advised leaps in trees that threatened injury to themselves or others.

He explained that Soumi discovered a correlation between low serotonin metabolism and aggressive behavior and a tendency to consume alcohol in an experimental “happy hour” situation.

Monkeys' Upbringing Impacts Outcome

The way the monkeys were reared was also found to have a moderating influence. The monkeys that were raised by their mothers were less likely to develop antisocial characteristics than those raised by peers. And in the natural environment, the quality of mothering was further associated with the development of antisocial personality, Gabbard said.

“The inherited propensity to develop patterns of impulsive aggression and consume alcohol can be modified by early attachment relationships,” Gabbard said. “Monkeys raised by peers instead of their mothers consistently showed lower serotonin in their cerebral spinal fluid and more alcohol consumption, compared with those reared by their own mothers.

“So both nature and nurture are at play in most, if not all, biobehavioral aspects of impulsive aggression, and the quality of mothering has a profound effect on gene expression.”

Gabbard said the findings have important implications for early intervention with high-risk children. He cited a report by David Olds and colleagues in the October 14, 1998, Journal of the American Medical Association on the impact of home visitation by a nurse on childhood antisocial behavior.

In that study, mothers who were under age 19, unmarried, or of low socioeconomic status were randomly assigned to either regular home nurse visits throughout pregnancy and up to the child's second birthday or to usual prenatal and well-child care. The nurses focused on three aspects of maternal function: health-related behaviors, competent care, and maternal personal development.

The teens whose mothers had received the nurse visits had significantly lower rates of antisocial behavior than control subjects, lower rates of substance abuse, and fewer lifetime sex partners, Gabbard said.

“Genes and environment are inextricably connected in the pathogenesis of antisocial behavior,” he concluded. “The heritable characteristics of the child often evoke certain kinds of parenting. So there is a complex interaction of the child's genes, the parents' genes, their fit in the environment, and how they mutually influence each other.”

Similarly, Gabbard said, research on borderline personality disorder shows an association between early childhood trauma and hyperreactivity of the hypothalamic-pituitary-adrenal (HPA) axis in response to chronic stress. The HPA axis is the neuroendocrine system that responds to stress and produces corticosteroids.

He drew attention to a probable correlation between HPA hyperactivity and the typical clinical picture presented by borderline patients. “If you have a hyperactive HPA axis, you are going to have a hypervigilant, anxious state that is linked to an internal representation of self and others,” Gabbard said. “You are likely to see others as potential persecutors and yourself as a victim.”

Psychoactive medication and psychotherapy can act synergistically to reverse the HPA hyperactivity, diminish hypervigilant anxiety, and improve the therapeutic relationship. In turn, psychotherapy can over time facilitate the capacity for “mentalization”—the ability to perceive the mind of others as distinct from one's own and hence to reconsider and reassess one's own perceptions of reality.

Development of that capacity is frequently arrested during childhood in borderline patients who have experienced trauma.

“Mentalization depends on a caregiver who treats the child as a mental agent and ascribes mental status to that child,” Gabbard said.“ So mentalizing grows directly out of attachment theory. Attachment security promotes the development of a sense of one's own mind and the awareness that others have mind, because you see that in a caregiver growing up.”

Brain imaging studies suggest that the neural networks activated during mentalization are distributed widely throughout the brain, making it difficult to locate “the mind” in one area of the brain or to reduce theories of the mind to simple neuroanatomical categories.

But Gabbard said psychotherapy with borderline patients can successfully change the brain as the patient develops the capacity to mentalize and to experience—possibly for the first time—a good and loving object in the therapist.

“Representations of others and self as translated in the transference occur in neural networks throughout the brain,” he said. “The capacity to see the therapist as helpful creates new neural networks involving representations of self and others while weakening the old networks.”

In this way, Gabbard said, “psychotherapy is a biological treatment.” ▪