Alternative dimensional models of personality disorder: finding a common ground

The recognition of the many limitations of the categorical model of personality disorder classification has led to the development of quite a number of alternative proposals for a dimensional classification. The purpose of this article is to suggest that future research work toward the integration of these alternative proposals within a common hierarchical structure. An illustration of a potential integration is provided using the constructs assessed within existing dimensional models. Suggestions for future research that will help lead toward a common, integrative dimensional model of personality disorder are provided.     

Neurobiological models of attention-deficit/hyperactivity disorder: a brief review of the empirical evidence

Attention-deficit/hyperactivity disorder (ADHD) is a psychiatric disorder characterized by inattention, impulsivity, and overactivity that begins in childhood. While considerable research has focused on the neurobiological substrates of this disorder, the specific nature of the brain dysfunction in ADHD has remained elusive. However, early data from pharmacological treatment studies, as well as from basic research in animals and humans, initially led several investigators to develop neurobiological models of ADHD. These models of ADHD and more recent evidence from neuropsychological, neuroimaging, neurochemical, and genetic research are briefly reviewed. While not completely consistent, the empirical data suggest that dysfunction in prefrontal-striatal neural circuits, as well as in brain stem catecholamine systems that innervate these circuits, may underlie the executive function deficits in ADHD.     

Clinical utility of dimensional models for personality pathology

Clinical utility is defined as the extent to which the DSM assists clinical decision makers in fulfilling the various clinical functions of a psychiatric classification system. Distinction is made between elements of diagnostic validity that are more or less conditional to utility (i.e., coverage, and consistency with etiology and prognosis) and components of clinical utility in the narrow sense of the term (i.e., user acceptability and accuracy, communication, reliability, subtlety, and clinical decision making). Clinical utility is often considered the driving force behind the respective revisions of the DSM system, yet it has been difficult if not impossible to obtain reasonable levels of clinical utility within categorical classifications of personality disorders. This paper presents evidence that a dimensional diagnostic system will substantially improve clinical utility, especially with respect to coverage, reliability, subtlety, and clinical decision making. In addition, some evidence suggests that the purely dimensional models outperform the so-called hybrid models (i.e., dimensional profiling of categories) with respect to coverage, consistency with etiology, subtlety, and clinical decision making. Several research options that might inform future revisions, including the choice or development of a dimensional classification, are suggested.     

Creativity, intelligence, and personality: a critical review of the scattered literature

The authors examined the relations among intelligence, personality, and creativity. They consider the concept and definition of creativity in conjunction with the qualifications that researchers in the field have suggested. The present authors briefly refer to historiometric studies but focus on psychometric intelligence and its relations to tests of divergent thinking (DT) and ratings of creativity. The authors consider the relation between personality and creativity in the context of Eysenckian 3-factor and 5-factor models of personality and with reference to DT tests and ratings of creativity. The authors also present recommendations for the future study of creativity.     

Neurobiological correlates of autism: a review of recent research.

This review paper integrates recent structural and functional imaging, postmortem, animal lesion, and neurochemical research about the pathophysiology of autism. An understanding of the neurobiological correlates of autism is becoming increasingly important as more children are diagnosed with the condition and funding for well-targeted interventions increases. Converging evidence suggests that autism involves abnormalities in brain volume, neurotransmitter systems, and neuronal growth. In addition, evidence firmly links autism with abnormalities in the cerebellum, the medial temporal lobe, and the frontal lobe. Potential implications of these findings and suggestions for future research are reviewed.     

Millon's dimensional model of personality disorders: a comparative study

Millon has proposed six fundamental dimensions of general personality functioning as providing the underlying structure of personality disorders. However, this widely-cited theoretical model has been the subject of few empirical studies. The purpose of the current study was to directly compare the validity of this model to the five-factor model with respect to their hypothesized relationships with personality disorder symptomatology. Participants were administered the predominant measures of general personality functioning for each theoretical model, along with an assessment of personality disorder symptomatology. The results found only weak support for the theoretical model of Millon. Limitations and suggestions for future research are discussed.     

An overview of issues related to categorical and dimensional models of personality disorder assessment

Despite long-standing efforts to improve the current diagnostic system for Axis II, problems remain with the categorical conceptualization of personality disorders (PDs). Due in part to these problems, interest has developed in dimensional models of PD classification. In this article, we discuss four issues relevant to categorical vs. dimensional assessment of PDs: (a) problems with self-reports in PD patients, (b) methodological issues in behavioral and clinician assessment of PDs, (c) challenges that arise when dimensional models are applied to patient and nonpatient samples, and (d) clinical implications of categorical and dimensional PD models. We suggest that researchers and clinicians address these concerns to avoid implementing a new PD assessment model that-although different from the current system-would otherwise remain fraught with difficulties.     

Judgment research and the dimensional model of personality

Comments on the original article "Plate tectonics in the classification of personality disorder: Shifting to a dimensional model," by T. A. Widiger and T. J. Trull. The purpose of this comment is to address (a) whether psychologists know how personality traits are currently assessed by clinicians and (b) the reliability and validity of those evaluations. Although Widiger and Trull argued that the shift to a dimensional model will improve the diagnosis of personality disorders, we can also expect that it will lead to improvements in evaluating personality traits.     

The search for dimensional structure differences between normality and abnormality: a statistical review of published data on personality and psychopathology

A statistical review of published data for 37 personality and psychopathology inventories was conducted to determine whether there are dimensional structure differences between clinical and nonclinical respondents. Correlation and factor-loading matrices from multiscale inventories and from specialized measures were tested for structural invariance across populations. There was relatively consistent evidence for high levels of similarity between normal and abnormal populations both in the number of factors that exist in the data matrices and in the factor patterns. The dimensional universes of normality and abnormality are apparently the same, at least according to data derived from contemporary assessment instruments. Categorical-taxonic differences between clinical and nonclinical populations, which were not examined, may nevertheless exist within contexts of dimensional structure similarity.     

Plate tectonics in the classification of personality disorder: shifting to a dimensional model

The diagnostic categories of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders were developed in the spirit of a traditional medical model that considers mental disorders to be qualitatively distinct conditions (see, e.g., American Psychiatric Association, 2000). Work is now beginning on the fifth edition of this influential diagnostic manual. It is perhaps time to consider a fundamental shift in how psychopathology is conceptualized and diagnosed. More specifically, it may be time to consider a shift to a dimensional classification of personality disorder that would help address the failures of the existing diagnostic categories as well as contribute to an integration of the psychiatric diagnostic manual with psychology's research on general personality structure.     

The representation of four personality disorders by the schedule for nonadaptive and adaptive personality dimensional model of personality

This study examined the relationships of the Schedule for Nonadaptive and Adaptive Personality (SNAP) model of personality to 4 targeted personality disorders (PDs) in a large multisite sample of patients. Data were examined from 529 patients, who were assigned 1 of 5 primary diagnoses: borderline, schizotypal, avoidant, and obsessive-compulsive PDs and major depression without PD. Patients were administered the SNAP questionnaire and results were compared among diagnostic groups and between patient groups and nonclinical norms. Results indicated that the dimensions of the model appear to have considerable promise in differentiating normal from abnormal personality, particularly in the propensity of individuals with PDs to manifest negative affects and interpersonal detachment. Furthermore, the model appeared to successfully distinguish specific PDs, a property that represents a particular challenge for dimensional models of personality.     

Transactional models between personality and alcohol involvement: a further examination

Although correlated changes between personality and alcohol involvement have been shown, the functional relation between these constructs is also of theoretical and clinical interest. Using bivariate latent difference score models, we examined transactional relations (i.e., personality predicting changes in alcohol involvement, which in turn predicts changes in personality) across two distinct but overlapping developmental time frames (i.e., across college and during young adulthood) using two large, prospective samples. Across college, there was some evidence that alcohol involvement predicted changes in personality; however, these findings were limited to models that included more proximal measures of alcohol use. When examined across a longer timeframe, we found no evidence that alcohol involvement significantly predicted changes in personality but found some evidence that personality predicted changes in alcohol use. We did find reliable evidence of correlated changes between personality and alcohol use, especially during emerging adulthood. The findings from our datasets highlight that the impact of alcohol involvement on personality change may be limited to shorter intervals during specific developmental time-frames and that the relation between changes in personality and alcohol involvement may be best viewed from a noncausal perspective.     

Behavioral and molecular genetic contributions to a dimensional classification of personality disorder

This article examines the possible contribution of behavioral and molecular genetic research to the development of a dimensional classification of personality disorder. It is argued that the results of molecular studies are too preliminary to have immediate nosological significance. However, behavioral genetic methods could play a useful role in constructing a classification that reflects the genetic architecture of personality disorder. It is also argued that the best approach to constructing a valid classification would be to integrate behavioral genetic methods with the construct validation framework used in test construction. An integrative approach is proposed that seeks to combine constructs from alternative dimensional models. It is suggested that strong evidence of a four-dimensional structure to personality disorder provides a way to organize a preliminary model. An initial set of primary traits to define these secondary domains would then be compiled from existing models and refined using a combination of traditional psychometric analyses and behavioral genetic methods. It is concluded that an etiologically based classification is feasible for the DSM-V.     

Culture, personality, and subjective well-being: integrating process models of life satisfaction

The authors examined the interplay of personality and cultural factors in the prediction of the affective (hedonic balance) and the cognitive (life satisfaction) components of subjective well-being (SWB). They predicted that the influence of personality on life satisfaction is mediated by hedonic balance and that the relation between hedonic balance and life satisfaction is moderated by culture. As a consequence, they predicted that the influence of personality on life satisfaction is also moderated by culture. Participants from 2 individualistic cultures (United States, Germany) and 3 collectivistic cultures (Japan, Mexico, Ghana) completed measures of Extraversion, Neuroticism, hedonic balance, and life satisfaction. As predicted, Extraversion and Neuroticism influenced hedonic balance to the same degree in all cultures, and hedonic balance was a stronger predictor of life satisfaction in individualistic than in collectivistic cultures. The influence of Extraversion and Neuroticism on life satisfaction was largely mediated by hedonic balance. The results suggest that the influence of personality on the emotional component of SWB is pancultural, whereas the influence of personality on the cognitive component of SWB is moderated by culture.     

Reversal theory and personality: A review

Reversal theory is a new “mode-based” theory of motivation and personality which challenges some fundamental assumptions in these two fields and systematically develops an alternative account which emphasizes the complexity, changeability, and even inconsistency of much of behavior and experience. The present paper introduces some of the main concepts of the theory, including those of metamotivation, reversal, telic and paratelic modes, and telic dominance, and shows how the general approach involved can be characterized as “structural phenomenological.” The experimental, psychometric, psychophysiological, and other types of research which have been generated by the theory are reviewed and shown to be generally supportive of it.     

Dimensional models of personality disorder: coverage and cutoffs

Two major challenges that must be addressed by dimensional models, if they are to be considered viable alternatives to the present categorical system for diagnosing personality disorders, involve the issues of coverage and cutoffs. Several dimensional models of personality and personality pathology are evaluated with these issues in mind. There is growing consensus for the relevance of at least four higher-order domains of personality functioning that are clearly related to personality pathology: neuroticism/negative affectivity/emotional dysregulation, extraversion/positive emotionality, dissocial/antagonistic behavior, and constraint/compulsivity/conscientiousness. A proposal for developing a dimensionally based diagnostic system for personality disorders incorporating these higher-order traits is offered.     

Relationship of personality to performance motivation: a meta-analytic review

This article provides a meta-analysis of the relationship between the five-factor model of personality and 3 central theories of performance motivation (goal-setting, expectancy, and self-efficacy motivation). The quantitative review includes 150 correlations from 65 studies. Traits were organized according to the five-factor model of personality. Results indicated that Neuroticism (average validity = -.31) and Conscientiousness (average validity = .24) were the strongest and most consistent correlates of performance motivation across the 3 theoretical perspectives. Results further indicated that the validity of 3 of the Big Five traits--Neuroticism, Extraversion, and Conscientiousness--generalized across studies. As a set, the Big Five traits had an average multiple correlation of .49 with the motivational criteria, suggesting that the Big Five traits are an important source of performance motivation.     

Neuropsychological impairments in the syndromes of schizophrenia: a comparison between different dimensional models

This study investigates the associations between the different symptom dimensions of schizophrenia and neuropsychological performances. Globally, the results replicate previously described associations. The "negative" dimension correlates with impaired sustained attention and working memory, thus suggestive of dorsolateral frontal cortex dysfunction. "Disorganization" correlates with the ability to inhibit proactive interference. thus with ventromedial frontal dysfunction. The results also add support to the view that the "psychotic" dimension described in three-dimension models includes in fact two distinct dimensions, (1) "hallucinations," here associated to episodic memory measures, and (2) "delusions", here associated to visuospatial attention, thus suggestive of mediotemporal and posterior neocortical dysfunction, respectively.