Special feature: psychobiologic perspectives on treatment of personality disorders.

The neurobiology of personality dimensions provides a theoretical framework for the design of pharmacologic treatment and studies in the PD patient. Neurotransmitter mediation of specific dimensions, such as novelty seeking, impulsivity, or schizotypy, suggests the usefulness of highly selective medications as clinical treatment and, simultaneously, as confirmatory dimensions. For example, the efficacy of SSRI antidepressants against impulsivity suggests both a clinical treatment and confirmation of the role diminished serotonergic function in impulse dysregulation. Similarly, the efficacy of neuroleptics against schizotypal symptoms supports the hypothesized role in the personality disorders lies in a better understanding of neurotransmitter and receptor function, using sophisticated PET neuroimaging techniques and receptor-specific radioligands to define the biologic basis of specific dimensions. As the focus of study gets smaller, we will no longer treat whole personalities, or even dimensions as we currently view them, but receptor-related functions. The challenge for the pharmacotherapist is to discriminate interpersonal from biologic pathologies, i.e., not to "biologize" all behavior.