The Diagnostic and Statistical Manual of Mental Disorders (DSM ) is under revision. One proposal for the pending DSM-V is dimensionalizing personality disorders, and the Five-Factor Model (FFM [2, 3]) has received the most attention, either as a supplement or replacement for axis II. Whereas the DSM-IV classifies maladaptive personality with 10 discrete disorders defined by unique criteria, the FFM describes personality in a continuous manner along 30 traits (facets) grouped into five factors () identified as reflecting the bulk of the variance among personalities (4
). The FFM is a promising candidate for the DSM-V because it has been shown to be biologically based, universal, temporally stable, and can avoid problems with the DSM-IV axis II categories including high comorbidity and arbitrary diagnostic thresholds (7
FFM, DSM-IV, and SWAP Descriptions of a Prototypic Case of Paranoid Personality Disordera
However, one significant issue seldom examined is whether the FFM will be clinically useful. Clinical utility means the extent to which a diagnostic system assists clinicians in fulfilling key clinical functions, including making treatment plans and prognoses, communicating with patients or other clinicians, and describing a patient's global personality or important personality problems (9
). The current study investigates a potential challenge the FFM may encounter with respect to its clinical utility.
The FFM proposal for psychopathology is to score a person with potential personality problems on each of the 30 facets from low to high (2
) as shown in the first column of . That is, the FFM uses the same descriptors to profile all cases and all types of personality. However, descriptors general enough to apply to many categories are inherently ambiguous. For instance, a low score on the “gregariousness” facet can mean paranoid fears (as in paranoid personality disorder), fear of not being liked by others (avoidant), or indifference to others (schizoid) (11
). A high score on “anger” can mean temper tantrums (histrionic) or lack of control over anger (borderline) (14
). Indeed, research in cognitive science (15
) has demonstrated that the meanings of descriptors are relative to the categories they describe (e.g., large molecule versus large mountain; open hand versus open bottle; strong woman versus strong man), and thus a modifier without any category information can be ambiguous. The DSM diagnostic criteria are less likely to suffer from this problem because the descriptors are specific and framed in the context of a diagnosis. We suggest, however, that FFM profiles without a diagnosis may not be specific enough to convey subtle but important clinical information.
In the current study, we attempt to demonstrate the ambiguity of FFM descriptors by having clinicians provide DSM-IV personality disorder diagnoses based on FFM descriptions alone. For instance, clinicians received an FFM description like the one shown in as a description of a hypothetical patient, and made DSM-IV diagnoses based only on that information. Previous studies (20
) showed that clinicians could translate DSM-IV personality disorders into FFM ratings with high interrater reliability (e.g., a prototype of avoidant personality disorder is agreed to be low on “gregariousness”). However, if FFM descriptors are ambiguous to clinicians, back-translating an FFM profile into a DSM-IV diagnosis should be difficult because it would be a many-to-one mapping. For instance, one needs to choose one specific meaning from many possible meanings of low “gregariousness” (e.g., paranoid fears or indifference to others) to make a DSM-IV diagnosis. Thus, difficulty in back-translating can serve as a demonstration of the ambiguity in FFM descriptions.
We also hypothesize that if the FFM traits alone are not specific enough to convey clinically important distinctions, clinicians might feel that the FFM's clinical utility is low. Following First et al.'s initial proposal (9
), we also asked clinicians to rate the FFM on measures of clinical utility.
Only a few studies have tested the clinical utility of the FFM and the results are mixed. The general procedure used in this past research was to have clinicians consider a patient, make either a DSM-IV or FFM assessment, and rate the clinical utility of the assessment system. However, the specific methods differed with respect to the level of detail with which clinicians processed each system. Sprock (22
) had clinicians assess case vignettes on the five broad factors of the FFM and found that they judged the FFM as less useful than the DSM-IV. But when Samuel and Widiger (23
) had clinicians assess case vignettes on the 30 facets of the FFM, requiring more detailed processing of the FFM, they judged the FFM as more useful than the DSM-IV. In a recent study by Spitzer et al. (24
), clinicians had to process the DSM-IV in much greater detail than in the previous studies; they read through all the diagnostic criteria of the DSM-IV personality disorders as part of the DSM-IV assessment. The results showed that their clinicians judged the DSM-IV as more useful than the FFM. Thus, past results taken together suggest that clinicians gave higher clinical utility judgments when they processed information in a more detailed way during assessment. This pattern is consistent with our hypothesis that the specificity of descriptors, which could be influenced by more detailed processing of patient information, can affect clinical use. Of interest, Spitzer et al. (24
) also found the FFM's utility to be lower than that of the Shedler-Westen Assessment Procedure (SWAP-200 [25–26]; see ). This finding is also consistent with our hypothesis because SWAP uses 200 concrete descriptors, only some of which describe any given case, rather than applying the same set of a limited number of traits to all cases.
Although previous studies provide suggestive evidence in support of our hypothesis, the current study more directly examines how ambiguities in patient descriptions may lower clinical use of a diagnostic system. In addition to back-translating FFM descriptions into DSM-IV diagnoses, our clinician participants rated the clinical utility of the FFM descriptions presented as profiles of hypothetical patients without other information about the patients. This method differs from the previous studies (22
), in which clinicians considered either a vignette or one of the clinician's actual patients before assessing utility, which could have disambiguated the meanings of the FFM descriptors. We predict that when an FFM description is presented alone without any specific context to disambiguate the description, clinicians would judge the clinical utility of the FFM to be low.
To summarize, we propose that the FFM descriptors may be too ambiguous to capture clinically important but subtle information. To test this proposal, we examine whether FFM descriptions alone are specific enough to allow clinicians to recognize known DSM-IV personality disorders, and whether ambiguities in FFM descriptors result in lower clinical utility of the FFM.
Two studies are reported. The first study examined cases of a single DSM-IV personality disorder (prototypic). The second study examined cases with multiple personality disorders (comorbid). The methods of Study 1 and Study 2 are presented next, followed by the results of both studies. An integrated discussion follows after the methods and results of both studies.