presents the items best picking the various DSM-IV Cluster B personality disorders. The antisocial items present a rather impulsive person, who does not plan well, and is egocentric, unstable, and not very attached to other people. The borderline items express strong feelings, anger, unstable emotions, impulsivity, social problems, and unreality. The histrionic items are also impulsive and unstable but in addition also exhibitionistic, histrionic (watch myself put on an act), and extraverted. Finally, the narcissistic items are also exhibitionistic, sociable, impulsive, and instable but in addition also aggressive and self-confident. One item, “My emotions are fairly well balanced” (reversed) is common to all Cluster B personality disorders. Histrionic and narcissistic PDs have three items together: covering, exhibitionism, acting, and fantasy. Antisocial and borderline PDs have egocentrism and unreality together, and antisocial and narcissistic share the dare-devil aspect.
Items from the Self-Report Questionnaire Selected to Assess Antisocial, Borderline, Histrionic, and Schizotypal PD Traits.
The structure of common items is in accordance with the comorbidity within Cluster B personality disorders (Deary, Peter, Austin, & Gibson, 1998
; Durrett & Westen, 2005
; Fossati et al., 2000
; Hyler & Lyons, 1988
; Kass, Skodol, Charles, Spitzer, & Williams, 1985
; Yang, Bagby, Costa, Ryder, & Herbst, 2002
). It is also in accordance with the common genetic and environmental causality within cluster B, with the highest common causality between antisocial and borderline PDs, and between histrionic and narcissistic PDs (Torgersen et al., 2008
). What they do not share of items also expresses their unique nature, the irresponsibility of antisocial PD, the anger and relation problems of borderline PD, the extraversion and intensity of histrionic PD, and the self-confident aspect in contrast to social insensitivity in narcissistic PD.
presents the psychometric aspects of the questionnaire and the interview. The Chronbach's Alpha is not high. This must be viewed on the background of the post hoc method to create the scales, based on a regression method to obtain the maximum prediction value in relation to the interview. Hence, the items are picked to represent a broad association to the interview, not because they fit together.
present the model fitting for the four Cluster B PDs. – present the heritability effects (A) and the not-shared-in-families environmental effects (E) for the latent liability factors and the separate questionnaire and interview variables. The effects are broken down into common and specific effects for questionnaire and interview in , and the coefficients are squared to show the effects.
Model Fitting Results for Antisocial, Borderline, Histrionic, and Narcissistic Personality Disorders
Parameter estimates from the best-fit model VIII for antisocial personality disorder. A stands for additive genetic and E for nonshared environmental effects.
Parameter estimates from the best-fit model VIII for narcissistic personality disorder. A stands for additive genetic and E for nonshared environmental effects.
Antisocial Personality Disorder
The results in model fitting for antisocial PD (APD) will be described in detail (see ). Model I, the full model, allowed for qualitative and quantitative sex effects and genetic, shared, and unique environmental effects for the latent index to APD as well as the APD measurements obtained by self-report questionnaire and interview. In models II and III, the qualitative and quantitative sex effects are dropped, respectively. An improvement in the quality of fit was produced both times, as indexed by the AIC. Working from model III, all familial environmental effects in model IV and all genetic effects in model V, were omitted. The quality of fit improved with model IV but deteriorated substantially with model V. Working from model IV, we then dropped one at a time, in models VI through VIII, additive genetic effects for the latent liability to APD and then the same for the APD measurements obtained by questionnaire and finally by interview. Of these three models, by far the best fit was obtained by model VIII, which dropped the specific genetic effects for the interview. The model was simplified further by dropping the specific genetic effect for the interview (model IX) and for the latent liability (model X), but the fit deteriorated substantially in both cases, indicating that model VIII was the best fit.
shows the parameter estimates for this best-fit model for APD. The latent liability to APD is indexed equally well by the questionnaire (λS = +0.67) and the interview (λI = +0.67). We did not constrain these two parameters to equality, but we did constrain the estimates of λI to be greater than or equal to λQ.
The parameter estimates are squared in to show the additive genetic and environmental estimates. As the best model state, there are no shared, familial environmental effects and no genetic effects for the interview. The heritability of the latent liability to APD is quite high, 69%. The heritability for the questionnaire is .46, .31 from the latent liability and .15 specific to the questionnaire. The nonshared environmental effects, including errors, for the interview are quite high, .55, suggesting considerable reliability deficiency. It thus seems that there only exists a familiarity, totally genetic, for APD as assessed by interview, to the extent that the antisociality is corroborated by self-report questionnaire information. The questionnaire, on the other hand, displays genetic effects outside the realm of interview APD.
Genetic and Environmental Effects for the Latent Factor, Common Effects, and Method-Specific Effects for the Questionnaire and the Interview
Borderline Personality Disorder
Model fitting results for borderline PD (BPD) were identical to those seen for APD producing model VIII as the best fit model (), with no shared, familial environmental effects and no specific genetic effect for the interview. shows the parameter estimates of this model for BPD, and presents the genetic and environmental effects. As with APD, the latent liability to BPD was equally well indexed by the questionnaire (λS = +0.69) and the interview (λI = +0.69). The heritability of the latent liability to BPD is estimated at 67%, slightly lower than that seen for APD. The heritability for the questionnaire is .46, .32 from the latent liability factor and .14 specific to the questionnaire. There are high non-shared, unique environmental effects, including errors, as found for APD.
Parameter estimates from the best-fit model VIII for borderline personality disorder. A stands for additive genetic and E for nonshared environmental effects.
Histrionic Personality Disorder
Model fitting for histrionic PD (HPD) is also very similar to the model fittings for APD and BPD. Model VIII () is even better for HPD than for APD and BPD. The latent liability to BPD is equally well indexed by the questionnaire (λQ = +0.64) and the interview (λI = +0.64) (). The heritability of the latent liability is 63% (, ). The heritability for the questionnaire is 46% (.26 from the latent liability and .20 from the questionnaire). As was found for the other PDs, the nonshared, unique environmental/error effects are high for the interview.
Parameter estimates from the best-fit model VIII for histrionic personality disorder. A stands for additive genetic and E for nonshared environmental effects.
Narcissistic Personality Disorder
The results for Narcissistic PD (NPD) are also similar to that of the three other PDs in Cluster B. The latent liability to NPD is equally well indexed by the questionnaire (λS = +0.57) and the interview (λI = +0.57) (). Model VIII is the best model with no shared, familial environment and no specific genetic effects for the interview (). NPD has the highest heritability of the four Cluster B PDs, .71 (, ). The heritability for the questionnaire is .41 (.23 from the latent liability and .18 questionnaire-specific). The interview-specific nonshared, unique environmental/error effects is very high, .67.