An empirical method to refine personality disorder classification using stepwise logistic regression modeling to develop diagnostic criteria and thresholds

OBSESSIVE-COMPULSIVE PERSONALITY DISORDER: EVIDENCE FOR TWO DIMENSIONS

BACKGROUND

To determine possible dimensions that underlie obsessive-compulsive personality disorder (OCPD) and to investigate their clinical correlates, familiality, and genetic linkage.

METHODS

Participants were selected from 844 adults assessed with the Structured Instrument for the Diagnosis of DSM-IV Personality Disorders (SIDP) in the OCD Collaborative Genetics Study (OCGS) that targeted families with obsessive-compulsive disorder (OCD) affected sibling pairs. We conducted an exploratory factor analysis, which included the eight SIDP-derived DSM-IV OCPD traits and the indecision trait from the DSM-III, assessed clinical correlates, and estimated sib-sib correlations to evaluate familiality of the factors. Using MERLIN and MINX, we performed genome-wide quantitative trait locus (QTL) linkage analysis to test for allele sharing among individuals.

RESULTS

Two factors were identified: Factor 1: order/control (perfectionism, excessive devotion to work, overconscientiousness, reluctance to delegate, and rigidity); and Factor 2: hoarding/indecision (inability to discard and indecisiveness). Factor 1 score was associated with poor insight, whereas Factor 2 score was associated with task incompletion. A significant sib-sib correlation was found for Factor 2 (rICC = .354, P < .0001) but not Factor 1 (rICC = .129, P = .084). The linkage findings were different for the two factors. When Factor 2 was analyzed as a quantitative trait, a strong signal was detected on chromosome 10 at marker d10s1221: KAC LOD = 2.83, P = .0002; and marker d10s1225: KAC LOD = 1.35, P = .006.

CONCLUSIONS

The results indicate two factors of OCPD, order/control and hoarding/indecision. The hoarding/indecision factor is familial and shows modest linkage to a region on chromosome 10.

The quality of the DSM-IV obsessive-compulsive personality disorder construct as a prototype category

The study evaluated the quality of the DSM-IV obsessive-compulsive personality disorder (OCPD) construct as a prototype category. A sample of 2237 patients from the Norwegian Network of Psychotherapeutic Day Hospitals was examined by a variety of psychometric analyses. A high number of OCPD patients (77%) had co-occurrent PDs, but only the co-occurrence with paranoid was significantly higher than expected. Exploratory factor analysis of the PD criteria indicated that OCPD consists of 2 dimensions. The first dimension, perfectionism, was constituted by OCPD criteria only and was significantly related to obsessive-compulsive disorder. The second dimension, aggressiveness, included 2 OCPD criteria, reluctance to delegate and stubbornness, but was also defined by criteria from paranoid, antisocial, and borderline PD. Confirmatory factor analysis of the OCPD criteria indicated a poor fit of both a unitary model and a 3-dimensional model. Overall, the OCPD criteria had poor psychometric properties. Although it seems that the quality of the DSM-IV OCPD as a prototype construct is insufficient, it may be improved by deleting the criteria hoarding behavior and miserliness. Alternative criteria could be related to problems in close relationships involving the need for predictability. Such revisions may add a third dimension to the 2 dimensions of perfectionism and aggressiveness.

An investigation of the validity of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition avoidant personality disorder construct as a prototype category and the psychometric properties of the diagnostic criteria

This study investigated several aspects of the validity of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition avoidant personality disorder (APD) construct, with emphasis on the psychometric properties of the diagnostic criteria and the prototype nature of the construct. A sample of 1,058 patients from the Norwegian Network of Psychotherapeutic Day Hospitals was examined by means of exploratory factor analysis, correlation, and diagnostic efficiency statistics, chi(2) analysis, and frequency distribution. The results indicated that APD is a 1-dimensional construct with good internal consistency. The criteria had acceptable diagnostic efficiency; criterion 3 performed poorest. Number of APD criteria showed no distinct threshold between No-APD and patients with APD. Sixty-two different combinations of any 4 APD criteria occurred. It can be concluded that the prototype model fitted the data well and that the APD diagnostic criteria perform well in the current classification system. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition hierarchy of criteria was not supported.

Evaluation of DSM-IV personality disorder criteria as assessed by the structured clinical interview for DSM-IV personality disorders

The primary objective of this research was to investigate the psychometric and diagnostic efficiency properties of DSM-IV personality disorder (PD) criteria as assessed by the Structured Clinical Interview for DSM-IV Personality Disorders (SCID-II). Logistic regression analyses were also employed to identify discriminating and nondiscriminating diagnostic criteria within specific PD categories. Results based on a community sample of 149 psychotropic medication-free persons, 58% of whom had at least one PD as determined from the SCID-II, suggest problems with the assessment and/or conceptualization of some PD categories, most notably obsessive-compulsive PD. For many PD concepts, diagnostic criteria were identified that either detracted from the overall internal consistency and diagnostic efficiency of their associated PD criteria set or failed to uniquely discriminate individuals with specific PDs from those without. Most of these findings cannot be clearly attributed to limitations associated with the method used to assess PD criteria.

Identifying personality disorders: towards the development of a clinical screening instrument

The study objective was to identify a set of personality disorder (PD) criteria from the DSM PD diagnostic sets that can be used to detect subjects with an increased likelihood of having a PD diagnosis. In a series of outpatients evaluated systematically in two waves for every criteria item for 12 DSM-III-R PDs, stepwise logistic regression identified 45 criteria as discriminative for their specific PDs, which are selected for further analysis to assess their ability to discriminate for any PD. Receiver operating characteristic (ROC) analysis is used to evaluate their discriminative power in an independent conjoined sample (N = 1,342) from six centers that assessed every PD criteria item by structured instrument (Structured Clinical Interview for DSM-III-R PDs [SCID-II, Personality Disorder Examination [PDE], and Structured Interview for DSM-III-R PDs [SIDP-R]). The cutoff that maximizes information gain is used to determine the diagnostic threshold (DT). Initially, 15 of 45 criteria are identified. At the 0.43 PD prevalence, a DT of 2 or more of the 15 PD criteria across samples is optimal. The maximum information gain (MIG) is .42 bits, and the AUR is 0.94+/-.007. Other performance indices at this cutoff are .90 sensitivity, .84 specificity, .81 positive predictive power (PPP), .91 negative predictive power (NPP), and .86 hit rate (HR). Taken collectively, the 15 PD criteria selected by the data reduction techniques suggest a narrowed set to be assessed in screening for the presence or absence of any PD with comparable or better psychometric properties than other tests routinely used for diagnosing medical and psychiatric disorders. If specific PD categorization is needed, a second-step comprehensive assessment should follow.

A mathematical typology analysis of DSM-III-R personality disorder classification: grade of membership technique

This study employed grade of membership (GoM) analysis in a clinical setting to determine if the DSM-III-R personality disorder (PD) diagnostic criteria cluster into recognizable disorders resembling the official axis II nosology. The GoM model, based on fuzzy-set theoretic concepts, explicitly examines medical diagnostic systems by quantitatively identifying and characterizing subpatterns of illness within a broad class. A semistructured assessment of 110 outpatients was performed for 12 PDs and their 112 diagnostic criteria. GoM analysis was performed using internal variables of the 112 PD criteria rated as present or absent. Demographic variables, axis I and II diagnosis (structured clinical Interview for DSM [SCID]), and treatment response (Global Adjustment Scale [GAS]) information were used as external validators. Four pure types (PT) provided the most satisfactory solution to the data. PT-I is characterized by marked maladaptive personality pathology, which is manipulative, egocentric, impulsive, and alloplastic. PT-II consists primarily of exaggerated socially anxious and detached traits. PT-III is sociably dependent and autoplastic. PT-IV is essentially asymptomatic. GoM provides a more parsimonious handling of the PD criteria than provided by classifying according to DSM categories. The analysis fails to confirm the natural occurrence of any single specific axis II PD or cluster.

Temporal stability of antisocial personality disorder: blind follow-up study at 8 years

The study objective was to examine the temporal stability of the antisocial personality disorder (ASPD) diagnosis based on whether specific antisocial symptoms were considered to be related to substance abuse. A total of 407 adults who were initially part of a family study of alcoholism and sociopathy were blindly reassessed an average of 8 years later, using the Home Environment and Lifetime Psychiatric Evaluation Record (HELPER) and basing diagnoses on the clinician's best final estimate using all sources of data. "Narrow" and "broad" ASPD diagnoses were made at both times based on whether individual symptoms were counted toward diagnosis if they occurred in the setting of significant substance abuse. kappa values varied from 0.31 to 0.68, with more restrictive methods of diagnosis being less stable. After deriving estimates of sensitivity and specificity of diagnosis, the probability of being a "case" could be assigned based on the reported number of conduct problems occurring before age 15 as a clinical covariate for diagnosis. We conclude that diagnosing ASPD without attempting to attribute the cause of individual symptoms to substance abuse results in substantially greater temporal stability. Using a broader definition, the diagnosis of ASPD is highly sensitive (P = .97) and specific (q = 0.93). These findings may allow more accurate diagnosis of ASPD in drug-abusing individuals.