A self-report version of the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist: psychometric properties of factor-based scales in three samples

Examining the factor structure of the self-report Yale-Brown Obsessive Compulsive Scale Symptom Checklist

Obsessive-compulsive symptom dimensions are important in studies about the pathogenesis and treatment of obsessive-compulsive disorder. More than 30 factor analytic studies using the Yale-Brown Obsessive Compulsive Scale Symptom Checklist (Y-BOCS-SC) interview version have been published. However, a drawback of the Y-BOCS-SC interview is that it is time-consuming for the clinician. Baer's self-report version of the Y-BOCS-SC could be a less time-consuming alternative. The purpose of this study was to examine the factor structure of Baer's self-report Y-BOCS-SC. In a sample of 286 patients, we performed two factor analyses, one using categories and one using items of the Y-BOCS-SC. Using category-level data, we identified four factors; when using items we identified six factors. Symptom dimensions for contamination/cleaning, symmetry/repeating/counting/ordering and hoarding were found in both analyses. The impulsive aggression, pathological doubt, sexual, religious somatic and checking categories formed one factor in the analysis using category-level data and divided into three factors using item-level data. These factors correspond with studies using the interview version and support our hypothesis that the self-report version of the Y-BOCS-SC could be an alternative for the interview version.

Getting it just right: A reevaluation of OCD symptom dimensions integrating traditional and Bayesian approaches

Previous research using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) suggests that the heterogeneous symptoms of obsessive-compulsive disorder (OCD) may reflect four underlying dimensions. However, past results vary substantially, which may be due to (a) the reliance on aggregated scores, (b) the common use of exploratory factor analyses, and (c) the exclusion of several symptoms. The present study tested the homogeneity of the original Y-BOCS categories using confirmatory factor analysis and modified categories where necessary. To test multidimensional models, data were further analyzed with Bayesian structural equation models, which better capture item heterogeneity in contrast to ordinary factor analysis. All analyses were run with two samples of patients with OCD allowing for cross-validation. Only a minority of the original Y-BOCS categories proved to be homogeneous. Modification yielded 10 homogeneous first-order factors, which can be reduced to four second-order factors: Incompleteness, Taboo Thoughts, Responsibility, and Contamination. This two-level factor model outperformed competing factor structures. The results corroborate the notion of four broader symptom dimensions in OCD, although the specific factor structure deviates from previous research. Differences presumably derive from using the full range of OCD symptoms and the combined exploratory and confirmatory approach with BSEM as a theoretically more appropriate analytical framework.

Delineating Characteristics of Maladaptive Repetitive Thought: Development and Preliminary Validation of the Perseverative Cognitions Questionnaire

Worry, rumination, and obsessive thinking are theorized to differ on temporal orientation, positive perceived function, degree of intrusiveness, and discordance with one's self-concept. However, prior findings with respect to such differences may be due to method variance of the measures used and/or inclusion of items confounded by diagnostic symptoms. Accurately capturing differences between types of perseverative thought linked to psychopathology and understanding whether such aspects are common across disorders or specific to some may be important to designing effective treatments for them. Two studies are presented detailing the development and validation of the Perseverative Cognitions Questionnaire (PCQ). The PCQ is a 45-item self-report measure that assesses six dimensional characteristics of worry, rumination, and obsessive thinking previously found to discriminate these thought styles: Lack of Controllability, Preparing for the Future, Expecting the Worst, Searching for Causes/Meaning, Dwelling on the Past, and Thinking Discordant with Ideal Self. Factor structure of the PCQ was established using principal components, exploratory factor, and confirmatory factor analyses. PCQ scales exhibited differential convergence with measures of perseverative thought and psychopathology. The PCQ also demonstrated acceptable retest correlations across 1- and 2-week periods, and incremental validity when predicting symptoms of anxiety, depression, and obsessive compulsive disorder.

"Not Just Right Experiences" as a psychological endophenotype for obsessive-compulsive disorder: Evidence from an Italian family study

The heart of the obsessional process may be considered the subject's underlying impression that "something is wrong" or "that something is not just as it should be". This phenomenon, labeled "not just right experiences" (NJREs), has increasingly been receiving attention as a possible marker of obsessive-compulsive disorder (OCD). The present study sought to add to the evidence that NJREs may be a putative endophenotype of obsessional symptoms. To this aim, measures of NJREs, obsessive-compulsive (OC) symptoms and psychological distress were compared in offspring of parents with and without OC symptoms. The offspring of parents with OC symptoms (N=120) reported higher frequency and severity of NJREs compared to offspring of parents without OC symptoms (N=106). Such differences remained significant for NJREs frequency and close to significance for NJREs severity, when general distress (i.e., anxiety and depression) was controlled. The possible role of NJREs as an endophenotype for OCD is discussed in reference to Gottesman and Gould criteria and the National Institute of Mental Health RDoC initiative.

Reliability and validity of the Thai self-report version of the Yale-Brown Obsessive-Compulsive Scale-Second Edition

PURPOSE

The self-report version of the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) has been developed to overcome the limitations of the clinician-administered version, which needs to be executed by trained personnel and is time consuming. The second edition of the Y-BOCS (Y-BOCS-II) was developed to address some limitations of the original version. However, there is no self-report version of the Y-BOCS-II at the moment. This study aimed to evaluate the psychometric properties of the developed Thai self-report version of the Yale-Brown Obsessive-Compulsive Scale-Second Edition (Y-BOCS-II-SR-T).

PATIENTS AND METHODS

Y-BOCS-II-SR-T was developed from the Thai version of the Yale-Brown Obsessive-Compulsive Scale-Second Edition (Y-BOCS-II-T). The Y-BOCS-II-SR-T, the Y-BOCS-II-T, the Thai version of the Florida Obsessive-Compulsive Inventory (FOCI-T), the Hamilton Rating Scale for Depression (HAM-D), the nine-item Patient Health Questionnaire (PHQ-9), and the Pictorial Thai Quality of Life (PTQL) instrument were administered to 52 obsessive-compulsive disorder (OCD) patients. Internal consistency for the Y-BOCS-II-SR-T was calculated with Cronbach's alpha coefficient (α), and the factor analyses were completed. Pearson's correlation was used in determining convergent and divergent validity among the other measures.

RESULTS

The mean score of the Y-BOCS-II-SR-T total score was 20.71±11.16. The internal consistencies of the Y-BOCS-II-SR-T total scores, the obsession subscale, and the compulsion subscale scores were excellent (α=0.94, α=0.90, and α=0.89, respectively). The correlation between each item and the Y-BOCS-II-SR-T total score showed strong correlation for all items. Confirmatory factor analysis with model modification showed adequate fit for obsession and compulsion factor models. The Y-BOCS-II-SR-T had strong correlation with the YBOCS-II-T and the FOCI-T (r s>0.90) and weaker correlation with the HAM-D, PHQ-9, and PTQL (r s<0.60), which implied good convergent and divergent validity.

CONCLUSION

The Y-BOCS-II-SR-T is a psychometrically sound and valid measure for assessing obsessive-compulsive symptoms.

Development and validation of the Japanese version of the obsessive-compulsive inventory

Background

The Obsessive-Compulsive Inventory (OCI) was designed to evaluate the severity of obsessive-compulsive symptoms in both clinical and non-clinical samples. The aim of the study was to develop a Japanese version of this scale (OCI-J) and validate it in both non-clinical and clinical Japanese samples.

Findings

In Study 1, the OCI-J, the Maudsley Obsessional Compulsive Inventory (MOCI), and measures of anxiety and depression were administered to 150 undergraduate students (non-clinical sample) in order to investigate the internal consistency and convergent validity of the OCI-J. Furthermore, 118 non-clinical participants completed the OCI-J after a 2-week interval to determine the test-retest reliability. In Study 2, OCD participants (n = 35), anxiety control participants with panic disorder (n = 22), and healthy control participants (n = 37) completed the OCI-J in order to test its clinical discrimination ability.

Correlational analysis indicated moderate to high correlations between the subscales and total scores of the OCI-J and MOCI. In addition, the OCI-J and its subscales demonstrated satisfactory test-retest reliabilities. Finally, the OCI-J showed good clinical discrimination for patients with OCD from healthy and anxiety controls.

Conclusions

The OCI-J is a valid and reliable instrument for measuring OCD symptoms in both clinical and non-clinical samples of Japanese.

Study of symptom dimensions and clinical characteristics in Chinese patients with OCD

BACKGROUND

The current study explored the main symptom dimensions and clinical characteristics of obsessive-compulsive disorder (OCD) in Chinese patients.

METHODS

Obsessive-compulsive (OC) symptoms of participants (N=512) were assessed through the Yale-Brown Obsessive Compulsive Scale Checklist (YBOCS-CL). Exploratory category-level and item-level factor analyses were performed. Regression analysis was carried out to study the relationships between clinical characteristics in our sample and the symptom dimensions obtained. Relationships among the clinical characteristics were explored using the chi-square test.

RESULTS

We found five symptom dimensions in the category-level analysis and six similar symptom dimensions in the item-level analysis. Moreover, the factors identified in our study overlapped with the results of prior studies. Association between gender and the symptom dimension of 'contamination/cleaning' was observed, with females showing more significant association with this dimension than males. Age of onset was associated with the symptom dimension of 'symmetry/arranging/repeating/counting', with the early-onset group more actively associated with this dimension than the late-onset group. Early-onset patients with OCD were more likely to be male and show tic comorbidity.

LIMITATIONS

Data from only one site do not represent the full range of Chinese OCD patients. Furthermore, past symptoms may show memory bias. Inherent problems in the YBOCS-CL have also been identified.

CONCLUSION

Symptoms in Chinese OCD patients are multidimensional. The main components of symptom dimensions of OCD patients show similarity or consistency among different regions and sociocultural backgrounds. The pathogenic mechanism of OCD may show potential distinctions.

Myth of the pure obsessional type in obsessive--compulsive disorder

BACKGROUND

Several studies have identified discrete symptom dimensions in obsessive-compulsive disorder (OCD), derived from factor analyses of the individual items or symptom categories of the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC). This study aims to extend previous work on the relationship between obsessions and compulsions by specifically including mental compulsions and reassurance-seeking. Because these compulsions have traditionally been omitted from prior factor analytic studies, their association to what have been called "pure obsessions" may have been overlooked.

METHOD

Participants (N = 201) were recruited from two multi-site randomized clinical treatment trials for OCD. The YBOCS-SC was used to assess OCD symptoms, as it includes a comprehensive list of obsessions and compulsions, arranged by content category. Each category was given a score based on whether symptoms were present and if the symptom was a primary target of clinical concern, and a factor analysis was conducted. Mental compulsions and reassurance-seeking were considered separate categories for the analysis.

RESULTS

Using an orthogonal geomin rotation of 16 YBOCS-SC categories/items, we found a five-factor solution that explained 67% of the total variance. Inspection of items that composed each factor suggests five familiar constructs, with mental compulsions and reassurance-seeking included with sexual, aggressive, and religious obsessions (unacceptable/taboo thoughts).

CONCLUSIONS

This study suggests that the concept of the "pure obsessional" (e.g., patients with unacceptable/taboo thoughts yet no compulsions) may be a misnomer, as these obsessions were factorially associated with mental compulsions and reassurance-seeking in these samples. These findings may have implications for DSM-5 diagnostic criteria.

Symptom dimensions in obsessive-compulsive disorder: from normal cognitive intrusions to clinical obsessions

Cognitive behavioral models of obsessive-compulsive disorder (OCD) assume continuity between normal obsessional intrusive thoughts (OITs) and obsessions. However, this assumption has recently been criticized. This article examines this issue using a new instrument (the Obsessional Intrusive Thoughts Inventory, INPIOS) specifically designed to assess the frequency and content of 48 OITs, which was completed by 734 community subjects and 55 OCD patients. Confirmatory factor analysis suggests six first-order factors included in two second-order factors, one containing aggressive, sexual, religious, immoral and repugnant OITs, and the other containing contamination, doubts and checking, symmetry and order, and superstition OITs. This structure integrates the research on OC symptoms and OITs. The INPIOS showed excellent known-groups validity, and it adequately represented obsessions as well as OITs. OCD and community subjects experience OITs representative of all types of obsessional contents. The dimensional structure is discussed in terms of OIT/obsessive-compulsive symptom structures currently proposed.

Symptom dimensions in OCD: item-level factor analysis and heritability estimates

To reduce the phenotypic heterogeneity of obsessive-compulsive disorder (OCD) for genetic, clinical and translational studies, numerous factor analyses of the Yale-Brown Obsessive Compulsive Scale checklist (YBOCS-CL) have been conducted. Results of these analyses have been inconsistent, likely as a consequence of small sample sizes and variable methodologies. Furthermore, data concerning the heritability of the factors are limited. Item and category-level factor analyses of YBOCS-CL items from 1224 OCD subjects were followed by heritability analyses in 52 OCD-affected multigenerational families. Item-level analyses indicated that a five factor model: (1) taboo, (2) contamination/cleaning, (3) doubts, (4) superstitions/rituals, and (5) symmetry/hoarding provided the best fit, followed by a one-factor solution. All 5 factors as well as the one-factor solution were found to be heritable. Bivariate analyses indicated that the taboo and doubts factor, and the contamination and symmetry/hoarding factor share genetic influences. Contamination and symmetry/hoarding show shared genetic variance with symptom severity. Nearly all factors showed shared environmental variance with each other and with symptom severity. These results support the utility of both OCD diagnosis and symptom dimensions in genetic research and clinical contexts. Both shared and unique genetic influences underlie susceptibility to OCD and its symptom dimensions.

The latent structure of obsessive-compulsive symptoms: a taxometric study

There is increasing consensus that obsessive-compulsive (OC) symptoms are heterogeneous clinical phenomena that should be assessed, diagnosed, and treated from a multidimensional perspective. However, it remains unclear whether the heterogeneous OC symptoms represent discrete taxonomic entities. In this study, the categorical versus dimensional nature of OC symptoms and associated cognitions was examined in a large undiagnosed sample using taxometric methods. Six potential OC symptoms (washing, checking, obsessing, neutralizing, ordering, and hoarding) and three potential OC-related cognitions (responsibility/threat estimation, perfectionism/certainty, and importance of thoughts/control of thoughts) were examined using the MAXimum EIGenvalue and mean above minus below a cut procedures. Findings were largely consistent with dimensional models of the latent structure of all OC symptoms and cognitions with the exception of hoarding. The implications of these findings for the clinical assessment and diagnosis of OC symptoms and obsessive-compulsive disorder are discussed.

Specificity and structure of obsessive-compulsive disorder symptoms

Research in obsessive-compulsive disorder (OCD) shows heterogeneous symptoms. No longer satisfied with categorizations of obsessions or compulsions, contemporary symptom measures are multidimensional and assess specific symptoms (e.g., checking, washing) as well as experiences bearing a putative relation to OCD (e.g., hoarding). This two-study correlational design examined three OCD measures in student samples (total N=805). Objectives were to evaluate (a) the measures' joint factor structure; (b) specificity of relations between OCD and symptoms of general distress, panic, and depression; and (c) the pattern of convergent and discriminant relations among OCD scales after accounting for general distress. Results were that both exploratory and confirmatory factor analyses supported a five-factor structure: checking, contamination, rituals, impulses, and hoarding. Scales showed meaningful patterns of relations with general distress, panic, and depression. That is, OCD symptoms correlated moderately with general distress and panic, but related more weakly to depression. Parallel scales measuring the five domains were reliable and showed strong convergence across instruments. After accounting for general distress, discriminant validity was found: Mono-trait correlations between instruments were the highest correlations overall and were substantially higher than hetero-trait values either within or between instruments. We discuss the importance of understanding relations among OCD measures, between OCD and other symptoms, and implications of this type of analysis for defining OCD.

Further psychometric analysis of the Florida Obsessive-Compulsive Inventory

This study examined the psychometric properties of the Florida Obsessive-Compulsive Inventory (FOCI [Storch, E. A., Stigge-Kaufman, D., Bagner, D., Merlo, L. J., Shapira, N. A., Geffken, G. R., et al. (2007). Florida Obsessive-Compulsive Scale: development, reliability, and validity. Journal of Clinical Psychology, 63, 851-859]). Participants were 89 adults with OCD presenting for treatment at a specialty clinic. A trained clinician administered the Yale-Brown Obsessive Compulsive Scale and patients completed the FOCI, Obsessive-Compulsive Inventory-Revised, Beck Depression Inventory-Second Edition, and State Trait Anxiety Inventory at baseline and following 14 weekly or daily cognitive behavioral therapy sessions. The internal consistency of FOCI Symptom Checklist and Severity Scale were good, and the concurrent and divergent validity of the FOCI Symptom Checklist and Severity Scale was supported through its associations with clinician-rated OCD symptom severity, and self-reported OCD, depressive, and anxiety measures. In addition, sensitivity to cognitive-behavioral treatment effects was shown as the Severity Scale scores were significantly lower following treatment compared to baseline. These findings not only replicate Storch et al. [Storch, E. A., Stigge-Kaufman, D., Bagner, D., Merlo, L. J., Shapira, N. A., Geffken, G. R., et al. (2007). Florida Obsessive-Compulsive Scale: development, reliability, and validity. Journal of Clinical Psychology, 63, 851-859] but also add unique construct validity data in support of the psychometrics of the FOCI.

Meta-analysis of the symptom structure of obsessive-compulsive disorder

OBJECTIVE

OCD is a clinically heterogeneous condition. This heterogeneity has the potential to reduce power in genetic, neuroimaging, and clinical trials. Despite a mounting number of studies, there remains debate regarding the exact factor structure of OCD symptoms. The authors conducted a meta-analysis to determine the factor structure of the Yale-Brown Obsessive Compulsive Scale Symptom Checklist.

METHOD

Studies were included if they involved subjects with OCD and included an exploratory factor analysis of the 13 Yale-Brown Obsessive Compulsive Scale Symptom Checklist categories or the items therein. A varimax-rotation was conducted in SAS 9.1 using the PROC FACTOR CORR to extract factors from sample-size weighted co-occurrence matrices. Stratified meta-analysis was conducted to determine the factor structure of OCD in studies involving children and adults separately.

RESULTS

Twenty-one studies involving 5,124 participants were included. The four factors generated were 1) symmetry: symmetry obsessions and repeating, ordering, and counting compulsions; 2) forbidden thoughts: aggression, sexual, religious, and somatic obsessions and checking compulsions, 3) cleaning: cleaning and contamination, and 4) hoarding: hoarding obsessions and compulsions. Factor analysis of studies including adults yielded an identical factor structure compared to the overall meta-analysis. Factor analysis of child-only studies differed in that checking loaded highest on the symmetry factor and somatic obsessions, on the cleaning factor.

CONCLUSIONS

A four-factor structure explained a large proportion of the heterogeneity in the clinical symptoms of OCD. Further item-level factor analyses are needed to determine the appropriate placement of miscellaneous somatic and checking OCD symptoms.