Anti-social personality disorder is defined as "a pervasive pattern of disregard for, and violation of, the rights of others that begins in childhood or early adolescence and continues into adulthood," according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) of the American Psychiatric Association.
DSM-IV provides formal diagnostic criteria for every psychiatric disorder. This process may be guided by rating scales that measure the traits and features associated with a personality disorder. But, until now, no one has studied the dimensional structure associated with the DSM antisocial personality disorder criteria.
Dr Kenneth Kendler of Virginia Commonwealth University and colleagues examined questionnaire and genetic data from adult twins. They found that the DSM-IV criteria do not reflect a single dimension of liability but rather are influenced by two dimensions of genetic risk reflecting aggressive-disregard and disinhibition.
Detect the underlying disorder
"When psychiatrists, as clinicians or researchers, think about our psychiatric disorders, we tend to think of them as one thing – one kind of disorder – a reflection of one underlying dimension of liability," said Dr Kendler. "This is also true of genetics researchers. We tend to want to identify and then detect 'the' risk genes underlying disorder X or Y."
Kendler added, "What is most interesting about the results of this paper is that they falsify this inherent and rather deeply held assumption. Genetic risk factors for anti-social personality disorder are not one thing. Rather, the disorder, as conceptualised by DSM-IV, reflects two distinct genetic dimensions of risk."
"The findings from this study make sense. The distinction between the two sets of heritable traits contributing to antisocial personality disorder, aggressive-disregard and disinhibition, highlights the complexity of unraveling the genes contributing to this personality style. We now have some puzzle pieces, but we have a long way to go to fit these pieces together," commented Dr John Krystal, editor of Biological Psychiatry.
(EurekAlert, February 2012)
The mind of a monster