Denise Milicevic

Preliminary validation of an ultra‐brief version of the Penn State Worry Questionnaire

The Penn State Worry Questionnaire (PSWQ) is widely regarded as the gold standard self-report questionnaire for pathological worry. However, the factorial structure of the scale remains contentious. We sought to determine whether a psychometrically sound brief version of the PSWQ, which avoids contentious items and yet incorporates the essential features of pathological worry, could be derived from the existing PSWQ item pool. After inspecting items of the PSWQ and the findings of previous factor analytic studies, three items were selected that capture the essence of pathological worry (i.e., high frequency, perceived uncontrollability and multiple domains of worry), according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition). We then compared the psychometric properties of the 3-item PSWQ with the full PSWQ in a sample of 225 clients attending an anxiety disorders clinic. Despite its brevity, the 3-item PSWQ had internal consistency comparable with that of the standard PSWQ, and performed equally well with regards to convergent and discriminant validity, in screening for a generalized anxiety disorder diagnosis and in detecting change with treatment. The 3-item ultra-brief version of the PSWQ is quick to administer, simple to score and possesses psychometric properties very similar to the 16-item version. Further research should confirm the psychometric properties of the 3-item version when administered independently of the other items and assess the scales test-retest reliability.

Functions of Compulsions in Obsessive–Compulsive Disorder

Objectives: The key function of compulsions in obsessive–compulsive disorder (OCD) is to alleviate anxiety or distress caused by the obsessions, but compulsions may also have other functions. The main aim of this study was to systematically ascertain what motivates individuals with OCD to perform compulsions. Method: A total of 108 adults with OCD were assessed with the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Functions of Compulsions Interview. The latter instrument elicits the functions of identified compulsions. Results: The functions of 218 compulsions were identified. The mean number of functions per compulsion in the whole sample was 2.94 and the vast majority of compulsions (85.3%) were performed for more than one reason. The total number of functions of compulsions endorsed for the three main compulsions correlated with Y-BOCS total scores (r = 0.37, p < 0.001). Compulsions were most frequently performed automatically and to decrease distress or anxiety, but there was substantial variation, depending on the type of compulsion. Hoarding was often performed for reasons not related to any other compulsion (involving a perceived need for collected objects), whereas ordering/symmetry/repeating compulsions were frequently performed to achieve a ‘just right’ feeling. Checking was frequently performed because of the belief that something bad or unpleasant would happen if one failed to check; washing/cleaning compulsions were most frequently performed to decrease distress or anxiety and automatically, and mental compulsions were performed automatically far more often than for other reasons. Conclusions: The majority of compulsions have more than one function and they are often performed automatically. The finding of different functions of compulsions in different types of compulsions provides some support to the subtyping of OCD on the basis of obsessions and compulsions. Identifying functions of compulsions allows better understanding of the functional relationship between obsessions and compulsions, which may have implications for cognitive-behavioural therapy of OCD.

Obsessive-compulsive personality disorder co-occurring with obsessive-compulsive disorder: Conceptual and clinical implications

Objectives: There are ongoing uncertainties in the relationship between obsessive–compulsive disorder (OCD) and obsessive–compulsive personality disorder (OCPD). This study aimed to test the proposition that OCPD may be a marker of severity of OCD by comparing groups of OCD individuals with and without OCPD on a number of variables. Method: A total of 148 adults with a principal diagnosis of OCD were administered the Mini International Neuropsychiatric Interview, Yale–Brown Obsessive–Compulsive Scale, Sheehan Disability Scale, Vancouver Obsessional Compulsive Inventory and Symptom Checklist 90-Revised. Participants with a DSM-IV diagnosis of OCPD were compared with those without OCPD. Results: Some 70 (47.3%) participants were diagnosed with OCPD. The groups of participants with and without OCPD did not differ significantly with respect to any of the demographic variables, clinician-rated severity of OCD, levels of disability and mean age of onset of OCD. All self-rated OCD symptom dimensions except for contamination and checking were significantly more prominent in participants with OCPD, as were all self-rated dimensions of psychopathology. Participants with OCPD had significantly more frequent hoarding compulsions and obsessions involving a need to collect and keep objects. Of Axis I disorders, only panic disorder was significantly more frequent in participants with OCPD than in those without OCPD. Conclusions: A high frequency of OCPD among individuals with OCD suggests a strong, although not necessarily a unique, relationship between the two conditions. This finding may also be a consequence of the blurring of the boundary between OCD and OCPD by postulating that hoarding and hoarding-like behaviours characterise both disorders. Results of this study do not support the notion that OCD with OCPD is a marker of clinician-rated severity of OCD. However, individuals with OCPD had more prominent OCD symptoms, they were more distressed and exhibited various other psychopathological phenomena more intensely, which is likely to complicate their treatment.

Obsessive-Compulsive Spectrum Disorders: a Comorbidity and Family History Perspective

Objective: The concept of obsessive-compulsive spectrum disorders (OCSDs) has become so influential that there are proposals to introduce it into new diagnostic classificatory systems. The aim of this paper was to assess whether rates of comorbidity and family history of OCSDs in patients with obsessive-compulsive disorder (OCD) supported this concept. Method: Comorbidity and family history were assessed in a group of participants with a primary diagnosis of OCD, using structured clinical interviews. Rates of OCSDs and other anxiety disorders (OADs), excluding OCD, were compared. Results: Of the 77 OCD participants assessed, the most prevalent comorbid conditions were OADs: generalized anxiety disorder (34.6%), specific phobia (26.9%), social phobia (21.8%) and panic disorder (19.2%). The proposed OCSDs were less frequently comorbid: tic disorder (12.8%), trichotillomania (5.1%), hypochondriasis (3.8%) and body dysmorphic disorder (BDD) (3.8%). Similar trends were observed for a family history of these disorders. No participant reported a family history of an OCSD without a family history of an OAD. Conclusions: Although the concept of OCSDs has invigorated thinking in this complex diagnostic field, these results support the current association of OCD with OADs rather than with OCSDs.

The characteristics of unacceptable/taboo thoughts in obsessive–compulsive disorder

BACKGROUND In the quest to unravel the heterogeneity of obsessive-compulsive disorder (OCD), an increasing number of factor analytic studies are recognising unacceptable/taboo thoughts as one of the symptom dimensions of OCD. AIMS This study aims to examine the characteristics associated with unacceptable/taboo thoughts. METHODS Using the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC) with 154 individuals with OCD, obsessive-compulsive symptoms were subjected to principal components analysis. The characteristics associated with the resulting symptom dimensions were then assessed using logistic and linear regression techniques. RESULTS Unacceptable/taboo thoughts comprised of sexual, religious and impulsive aggressive obsessions, and mental rituals. Higher scores on an unacceptable/taboo thoughts symptom dimension were predicted by higher Y-BOCS obsession subscores, Y-BOCS time preoccupied by obsessions scores, Y-BOCS distress due to obsessions scores, importance of control of thought ratings, male gender, and having had treatment prior to entering into the study. Unacceptable/taboo thoughts were also predicted by greater levels of hostility, and a past history of non-alcohol substance dependence. CONCLUSIONS An unacceptable/taboo thought symptom dimension of OCD is supported by a unique set of associated characteristics that should be considered in the assessment and treatment of individuals with these symptoms.

Disgust propensity in obsessive–compulsive disorder: Cross-sectional and prospective relationships

BACKGROUND AND OBJECTIVES Findings from non-clinical samples suggest that disgust propensity is associated with contamination concerns in obsessive-compulsive disorder (OCD). However, studies of clinical samples have yielded conflicting results. We investigated the relationship between disgust propensity and OCD symptoms in a clinical sample and examined whether changes in disgust propensity are associated with changes in OCD symptoms. METHODS One hundred and nine OCD participants completed measures of disgust propensity and OCD symptoms. Sixty of these underwent a six-month follow-up assessment. RESULTS At the baseline assessment, disgust propensity was associated with all OCD symptom dimensions except hoarding. Changes in overall disgust propensity between baseline and the six-month follow-up assessment were associated with changes in overall self-reported OCD symptoms but not with changes in contamination-based OCD symptoms or changes in interviewer-assessed OCD symptoms. LIMITATIONS There was substantial participant attrition between the baseline and follow-up assessments. CONCLUSIONS Our study is the first to investigate prospective relationships between disgust propensity and OCD across a six-month interval. Our findings suggest that if there is an association between changes in disgust propensity and changes in contamination-based OCD symptoms its magnitude is likely to be small.

The Relationships Between Obsessive–Compulsive Symptom Dimensions and Cognitions in Obsessive–Compulsive Disorder

Several studies have linked obsessive–compulsive symptoms to specific obsessive–compulsive cognitions, however methodologies have varied, and no study has determined obsessive–compulsive symptoms using the most widely used clinician rating scale, the Yale–Brown Obsessive–Compulsive Scale (Y-BOCS). Considering that almost all studies that used factor analysis to ascertain OCD symptom dimensions were based on the Y-BOCS and that self-report instruments assessing obsessive–compulsive symptoms correlate poorly with the Y-BOCS, there is a need to use the Y-BOCS to examine the relationship between obsessive–compulsive cognitions and obsessive–compulsive symptom dimensions. This study examined the relationship between five Y-BOCS-derived obsessive–compulsive symptom dimensions and the three obsessive–compulsive cognitive domains identified by the obsessive-beliefs questionnaire (OBQ). The symmetry/ordering symptom dimension was associated with increased perfectionism/intolerance of uncertainty, the unacceptable/taboo thoughts symptom dimension was associated with increased importance/control of thoughts and the doubt/checking symptom dimension was associated with increased responsibility/threat estimation. There was no statistical evidence of an association between any OBQ belief sub-scale and the hoarding symptom dimension nor the contamination/cleaning symptom dimension. The findings encourage symptom-based approaches to cognitive-behavioural therapy for some OCD symptoms and call for further research on cognitions associated with contamination/cleaning symptoms and hoarding.

The nature and correlates of avoidance in obsessive–compulsive disorder

Objectives: Avoidance in obsessive–compulsive disorder (OCD) has been neglected by research. This study aimed (i) to collect information on the nature and frequency of avoidance in people with OCD and ascertain the types of obsessions related to avoidance; (ii) compare OCD individuals with and without avoidance, and (iii) determine predictors of avoidance in people with OCD. Method: A total of 124 OCD adults underwent a comprehensive assessment. Participants were asked whether they engaged in any avoidance behaviour because of their OCD, and the nature and number of instances of such avoidance were recorded. The instances of avoidance were grouped according to the type of obsession and compulsion that they were related to. Results: A total of 74 (59.7%) participants reported OCD-related avoidance. Avoidance was most commonly related to contamination obsessions. Almost 80% of all contamination obsessions and more than 50% of all aggressive obsessions were associated with avoidance, and contamination obsessions were significantly more common among the participants with avoidance. In contrast, very few obsessions about a need to collect and keep objects and obsessions about a need for ordering, arranging and doing things right or in an exact way were associated with avoidance; these types of obsessions were also significantly more common among the participants without avoidance. The strongest predictor of avoidance was the presence of contamination obsessions. Participants with avoidance had a significantly more severe OCD than those without avoidance. Conclusions: Avoidance is common in OCD, and it is particularly frequently associated with contamination obsessions. There is a weak link between avoidance and hoarding and between avoidance and ordering/arranging/symmetry obsessions and compulsions. These results, along with the finding that OCD with avoidance is a more severe illness, have implications for the future diagnostic criteria, description, subtyping and treatment of OCD and for its relationship with other anxiety disorders.

The Factor Structure of the Kessler-10 Questionnaire in a Treatment-Seeking Sample

The Kessler-10 (K10) questionnaire was developed as a screening instrument for nonspecific psychological distress. Although it was validated using epidemiological samples, it is increasingly being used in clinical settings. We sought to determine whether the factor structure of the K10 as established in epidemiological samples, could be replicated in a sample of treatment seeking adults. We used confirmatory factor analysis to investigate two established models of the factor structure of the K10 in a sample of clinic attendees. Neither the single factor model of Kessler et al., Psychol Med. 2002;32:959–976, nor the multifactorial model of Brooks et al., Psychol Assess. 2006;18:62–70 fitted the data. Respecification of the Kessler et al. model to reduce item redundancy did not result in adequate fit. These findings call into question the construct validity of the K10 in treatment seeking samples, and the suitability of the scale for clinical settings may need to be reconsidered.

The clinical characteristics of obsessive compulsive disorder associated with high levels of schizotypy

Objectives: This study aims to examine the characteristics of obsessive compulsive disorder (OCD) associated with high levels of schizotypy. Methods: Using the Schizotypal Personality Questionnaire (SPQ) with 177 individuals with OCD, patients with OCD and high levels of schizotypy (OCD-HS) were compared to patients with OCD and low levels of schizotypy (OCD-LS) on a range of clinical characteristics. Self-report and clinician-administered instruments were used. Results were adjusted for the severity of OCD symptoms, age, marital status and comorbidity using logistic regression. Results: Patients with OCD-HS were younger and less likely to have been married. OCD-HS was associated with higher rates of symmetry/order obsessions, ordering/arranging compulsions, checking compulsions, co-occurring major depression, post-traumatic stress disorder, substance use disorders and greater general psychopathology. Previously reported associations, such as higher total scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) were not significant when adjusted for differences in demographic variables and comorbidity. Conclusions: Patients with OCD-HS were associated with specific OCD symptoms and comorbid conditions and may warrant a specific treatment approach.