Exploring personality ‐ personality disorder relations and their implications for DSM‐5

In Widiger’s thoughtful review of the manner in which personality and psychopathology may be related, he touched briefly on the relations between personality and personality disorders (PDs). This topic is expanded upon here as it is an important and timely issue, especially as it pertains to the upcoming release of DSM-5, the internationally influential diagnostic taxonomy for psychiatry and psychology. As Widiger noted, there is compelling evidence to suggest that PDs can be conceived of as “maladaptive and/or extreme variants of the FFM (Five Factor Model) personality structure”. There are a number of different research lines and studies that support this conceptualization: a) researchers and clinicians can easily and reliably rate PDs using the 30 traits of the FFM 1,2; b) individuals’ scores on these traits can be scored to assess the PDs in a valid manner 3,4; c) the factor structure of PDs can be readily interpreted using a five-factor framework 5; and d) these general traits can be used to understand the pattern of comorbidity observed among the PDs 1. An additional benefit of the use of such a personality model in the conceptualization and diagnosis of PD is that this structure is “robust across major regions of the world” 6. Others have argued that DSM-IV PDs are “hybrids of more stable traits and less stable symptomatic behaviors” 7. These authors suggested that these more stable traits may be the “prime candidates for retention” in DSM-5, given that there is an emphasis on “stability and resistance to change” in the PD criteria in DSM-IV 8. Another reason for researchers and clinicians to focus on these stable traits is that data suggest that changes to these underlying traits results in changes in PD symptoms, whereas the converse is not true 9. Warner et al 9 stated that “these results coincide with the clinical belief that lasting personality change may require more than targeting specific behaviors or symptoms”. Ultimately, it makes sense from both a clinical and empirical standpoint to focus on these stable traits in the conceptualization and assessment of PDs. It appears that the DSM-5 will incorporate a dimensional trait model that can be used to describe traditional PDs that are set for inclusion (e.g., borderline PD) and exclusion (e.g., narcissistic PD) from the DSM-5, as well as other less common forms of PD. Although one may disagree with the manner with which this trait model was developed, and/or the resultant model itself, the inclusion of a trait model is a step in the right direction. Yet, despite strong empirical support for these types of dimensional trait models of PD, many prominent scholars disagree vehemently with the DSM-5 proposal. For example, 29 psychologists and psychiatrists, led by noted scholar J. Gunderson, wrote an email to the DSM-5 Personality and Personality Disorder Work Group criticizing the proposal 10. These experts suggest that “there remains a huge gap between the science of personality traits or dimensional models and clinical practice… much of the language involves descriptors that are either unfamiliar to clinicians or require so much inference that reliability is likely to be very hard to attain”. With all due respect, this sentiment is inconsistent with existing data that demonstrate that dimensional traits can be rated by clinicians who are unfamiliar with the underlying trait model in a reliable and valid manner and that these traits can be used in isolation and combination to provide clinically useful information 11,12. The explicit recognition of the fundamental relation between personality traits and PDs is an important step in building a diagnostic taxonomy that is both valid and clinically useful.