Obsessive-compulsive disorder symptom dimensions show specific relationships to psychiatric comorbidity

Impact of depressive and anxiety disorder comorbidity on the clinical expression of obsessive-compulsive disorder

BACKGROUND

The identification of distinct subtypes based on comorbidity offers potential utility in understanding variations in the clinical expression of obsessive-compulsive disorder (OCD). Hence, we examined the hypothesis whether patients with OCD with major depressive disorder (MDD) or anxiety disorder comorbidity would differ from those without in terms of phenomenology.

METHODS

A total of 545 consecutive patients who consulted a specialty OCD clinic during the period 2004 to 2009 at a psychiatric hospital in India formed the sample. They were evaluated with the Yale-Brown Obsessive-Compulsive Scale (YBOCS), the Mini International Neuropsychiatric Interview, and the Clinical Global Impression scale.

RESULTS

Among 545 patients, 165 (30%) had current MDD, and 114 (21%) had current anxiety disorder comorbidity. Patients with OCD with MDD were mostly women who had a greater severity of OCD symptoms, more of obsessions (especially religious), greater occurrence of miscellaneous compulsions (need to confess or need to touch), higher suicidal risk, and past suicidal attempts. Patients with OCD with anxiety disorder had an earlier onset of illness that was associated with prior life events, less of compulsions, more of aggressive and hoarding obsessions, pathologic doubts, checking, and cognitive compulsions.

CONCLUSIONS

Obsessive-compulsive disorder, when comorbid with MDD, is more severe and is associated with higher suicidal risk. On the other hand, anxiety disorder comorbidity seems to influence not so much the morbidity but the phenotypic expression of OCD.

Clinical features of tic-related obsessive-compulsive disorder: results from a large multicenter study

OBJECTIVE

To evaluate the clinical features of obsessive-compulsive disorder (OCD) patients with comorbid tic disorders (TD) in a large, multicenter, clinical sample.

METHOD

A cross-sectional study was conducted that included 813 consecutive OCD outpatients from the Brazilian OCD Research Consortium and used several instruments of assessment, including the Yale-Brown Obsessive-Compulsive Scale, the Dimensional Yale-Brown Obsessive-Compulsive Scale, the Yale Global Tic Severity Scale (YGTSS), the USP Sensory Phenomena Scale, and the Structured Clinical Interview for DSM-IV Axis I Disorders.

RESULTS

The sample mean current age was 34.9 years old (SE 0.54), and the mean age at obsessive-compulsive symptoms (OCS) onset was 12.8 years old (SE 0.27). Sensory phenomena were reported by 585 individuals (72% of the sample). The general lifetime prevalence of TD was 29.0% (n = 236), with 8.9% (n = 72) presenting Tourette syndrome, 17.3% (n = 141) chronic motor tic disorder, and 2.8% (n = 23) chronic vocal tic disorder. The mean tic severity score, according to the YGTSS, was 27.2 (SE 1.4) in the OCD + TD group. Compared to OCD patients without comorbid TD, those with TD (OCD + TD group, n = 236) were more likely to be males (49.2% vs. 38.5%, p < .005) and to present sensory phenomena and comorbidity with anxiety disorders in general: separation anxiety disorder, social phobia, specific phobia, generalized anxiety disorder, post-traumatic stress disorder, attention-deficit hyperactivity disorder, impulse control disorders in general, and skin picking. Also, the "aggressive," "sexual/religious," and "hoarding" symptom dimensions were more severe in the OCD + TD group.

CONCLUSION

Tic-related OCD may constitute a particular subgroup of the disorder with specific phenotypical characteristics, but its neurobiological underpinnings remain to be fully disentangled.

Obsessive-compulsive disorder and comorbid depression: the role of OCD-related and non-specific factors

Although comorbid depression is a predictor of poor treatment response in obsessive-compulsive disorder (OCD), there is limited understanding of factors that contribute to depression severity in OCD. The current study examines the influence of OCD-related factors (autogenous obsessions and obsessional beliefs) and non-specific factors (avoidance and anxiety) on depression severity in a sample of OCD patients. There were 56 participants with only OCD and 46 with OCD and comorbid depression. Self-report questionnaires measuring depression, OCD-related factors, and non-specific factors were completed. Although there were no significant differences between the two groups on these variables, depression severity was positively correlated with anxiety, avoidance, obsessional beliefs, and autogenous obsessions in the whole sample. When entered into a multiple regression model to predict depression severity, these factors accounted for 51% of the variance. While OCD-related factors remained significant predictors after controlling for non-specific factors, the non-specific factors made the most significant contributions to the model. Our findings suggest that in addition to dealing with autogenous obsessions, addressing anxiety and avoidance might lead to improvements in the treatment of OCD with comorbid depression.

The nature, assessment, and treatment of obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is an anxiety disorder that affects between 1% to 2% of individuals and causes considerable impairment and disability. Although > 50% of individuals experience symptom onset in childhood, symptoms can continue to develop throughout adulthood. Accurate and timely assessment of clinical presentation is critical to limit impairment and improve prognosis. Presently, there are 2 empirically supported treatments available for OCD in children and adults, namely cognitive-behavioral therapy and pharmacotherapy with serotonin reuptake inhibitors. This article provides an introduction to the phenomenology, etiology, and clinical course of OCD. Assessment practices used to evaluate symptom severity are described, and evidence-based treatment options are reviewed, with appropriate distinctions drawn between children and adults. Finally, recommendations for assessment and treatment practices for OCD are explicated.

Depression in youth with obsessive-compulsive disorder: clinical phenomenology and correlates

This study examined differences in clinical presentation and functional impairment in youth with obsessive-compulsive disorder (OCD) with or without comorbid depressive disorders and sought to determine the predictors of youth-reported depressive symptoms. One-hundred and sixty youth were reliably diagnosed with OCD and comorbid disorders using the Anxiety Disorders Interview Schedule for DSM-IV: Parent version (Silverman and Albano, 1996) and confirmed by an experienced clinician. Sixteen percent (n = 25) had a comorbid diagnosis of a current depressive disorder (DD). Significantly more females than males had a DD. Those with a DD showed increased OCD symptom severity, OCD-related functional impairment, and family accommodation relative to those without a comorbid DD. Depressive symptoms were significantly positively correlated with years of age, degree of OCD symptom severity, measures of OCD-related functional impairment, and non-OCD anxiety symptoms. Hierarchical regression analyses showed that age, gender, functional impairment, and non-OCD anxiety were significant predictors of depressive symptoms, even when OCD symptom severity was controlled. Notably, functional impairment was a partial mediator of the relationship between OCD symptom severity and depression levels, suggesting depression levels are the product of both degree of symptoms and amount of day-to-day impairment. Results are discussed in terms of implications for assessment and treatment.

Childhood Experiences and Adult Beliefs in Obsessive-Compulsive Disorder: Evaluating a Specific Etiological Model

Cognitive accounts of obsessive-compulsive disorder (OCD) propose that an individual’s early experiences contribute to the development of different belief domains, which in turn represent fertile ground for the development of the disorder (e.g., Salkovskis, Shafran, Rachman, & Freeston, 1999). This study examined the proximal relationship between specific, narrowly defined childhood experiences (CEs) and distinct adult OCD-related beliefs (Obsessive Beliefs Questionnaire-87 [OBQ-87]) through the self-reports of 83 participants with OCD and 213 unselected student participants. CEs variables were operationalized via theoretical groupings of items on an early experience questionnaire (QEE) relevant to distinct OBQ belief domains. These proximal relationships were assessed according to predictions from both a specific and a nonspecific vulnerability hypothesis. Correlational analyses were supportive of both but mostly of a nonspecific vulnerability model. Results are discussed regarding the understanding of the possible multideterministic pathways to OCD development.

[Eating disorders (ED) and obsessive-compulsive disorders (OCD): common factors]

Several similarities exist in the phenomenology of obsessive-compulsive disorder (OCD) and eating disorders (ED : anorexia nervosa and bulimia). Both disorders include obsessive thoughts and compulsive or ritualized behaviours. Furthermore, these two disorders frequently present with similar comorbid disorders. In this article, the authors examine similarities between ED and OCD, and whether eating disorders can be conceptualized as a variant of obsessive-compulsive disorders. This raises the possibility that treatments proven effective for OCD could be successfully adapted for ED. The authors consequently further examine both treatments utilized for both disorders.

Unilateral right anterior capsulotomy for refractory major depression with comorbid obsessive-compulsive disorder

BACKGROUND

Treatment-resistant major depression (MDD) and obsessive-compulsive disorder (OCD) remain a major cause of suffering and disability. These disorders may be treated with functional neurosurgery that almost always is bilateral but some patients might benefit from unilateral procedures.

METHODS

We performed a unilateral right anterior capsulotomy (AC) in a 45-year-old right-handed woman with MDD and comorbid OCD. This unilateral procedure was based on the results of neuropsychological testing and an 18-Fluorodeoxyglucose positron emission tomography (FDG-PET) that revealed right hemisphere deficits in this patient.

RESULTS

Following surgery, Hamilton Depression scale (HAM-D) decreased 57% at 1 and 2 years and 54% at 3 years and Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) decreased 58% at 1 year, 77% at 2 years, and 96% at 3 years. There was a slight decrement of verbal memory and phonemic fluency after the procedure that could also be related to changes in medication. Right basal ganglia abnormalities revealed by FDG-PET remained unchanged 16 months postoperatively.

CONCLUSIONS

Overall this unilateral right AC was effective for the treatment of this woman's disorders with minimal adverse side effects.

Is childhood OCD a risk factor for eating disorders later in life? A longitudinal study

BACKGROUND

It has been suggested that childhood obsessive-compulsive disorder (OCD) may be a risk factor for the development of an eating disorder (ED) later in life, but prospective studies are lacking. We aimed to determine the prevalence of ED at follow-up and clinical predictors in a longitudinal clinical sample of adolescents/young adults diagnosed with OCD in childhood.

METHOD

All contactable (n=231) young people with OCD assessed over 9 years at a national and specialist paediatric OCD clinic were included in this study. At follow-up, 126 (57%) young people and parents completed the ED section of the Developmental and Well-being Assessment. Predictors for ED were investigated using logistic regression.

RESULTS

In total, 16 participants (12.7%) had a diagnosis of ED at follow-up. Having an ED was associated with female gender and persistent OCD at follow-up. There was a trend for family history of ED being predictive of ED diagnosis. Five (30%) of those who developed an ED at follow-up had ED symptoms or food-related obsessions/compulsions at baseline. A difference in predictors for an ED versus other anxiety disorders at follow-up was identified.

CONCLUSIONS

This study provides initial evidence that baseline clinical predictors such as female gender and family history of ED might be specific to the later development of ED in the context of childhood OCD. Clinicians should be alert to ED subthreshold symptoms in young girls presenting with OCD. Future longitudinal studies are needed to clarify the relationship between childhood OCD and later ED.

Comorbidity in hoarding disorder

BACKGROUND

Hoarding Disorder (HD) is currently under consideration for inclusion as a distinct disorder in DSM-5 (1). Few studies have examined comorbidity patterns in people who hoard, and the ones that have suffer from serious methodological shortcomings including drawing from populations already diagnosed with obsessive compulsive disorder (OCD), using outdated definitions of hoarding, and relying on inadequate assessments of hoarding. The present study is the first large-scale study of comorbidity in a sample of people meeting recently proposed criteria for hoarding disorder (1) and relying on validated assessment procedures.

METHODS

We compared psychiatric comorbidity in a large HD sample (n = 217) to 96 participants meeting criteria for OCD without HD.

RESULTS

High comorbidity rates were observed for major depressive disorder (MDD) as well as acquisition-related impulse control disorders (compulsive buying, kleptomania, and acquiring free things). Fewer than 20% of HD participants met criteria for OCD, and the rate of OCD in HD was higher for men than women. Rates of MDD and acquisition-related impulse control disorders were higher among HD than OCD participants. No specific anxiety disorder was more frequent in HD, but social phobia was more frequent among men with HD than among men with OCD. Inattentive ADHD was diagnosed in 28% of HD participants and was significantly more frequent than among OCD participants (3%).

CONCLUSIONS

These findings form important base rates for developing research and treatments for hoarding disorder.

Obsessive-compulsive disorder in children and adolescents: symptom dimensions in a naturalistic setting

BACKGROUND

Obsessive-compulsive disorder (OCD) is a frequent and clinically heterogeneous disorder. The complex clinical presentation can be summarized using a few consistent and temporally stable symptom dimensions. Only few studies in children and adolescents have examined the importance of symptom dimensions.

AIMS

This retrospective study was undertaken to describe the relation between symptom dimensions, pattern of comorbidity and family disposition, in a sample of Danish children and adolescents with OCD assessed in a naturalistic setting.

METHODS

A retrospective study of children and adolescents (n=83) diagnosed with OCD in the period 1998-2004, at the Psychiatric Hospital for Children and Adolescents, Risskov, Denmark. Information from clinical records was systematically collected and Children's Yale-Brown Obsessive-compulsive Scale (CY-BOCS) scores and symptom checklists were obtained.

RESULTS

High scores on the symmetry/ordering dimension were related to OCD in first-degree relatives and high scores on the aggressive/checking dimension were associated to comorbidity with tic disorders. We showed a correlation between limited insight and younger age.

CONCLUSION

This is one of the first studies to examine symptom dimensions in children and adolescents in naturalistic settings. The results were comparable with those in adult studies, showing an association between the occurrence of the symmetry/ordering dimension and family OCD and the occurrence of the aggressive/checking dimension and comorbid tic disorders. In small children, insight into symptoms may be limited.

Alexithymia in obsessive-compulsive disorder: clinical correlates and symptom dimensions

Previous studies have indicated that obsessive-compulsive disorder (OCD) is associated with alexithymic traits. The purpose of the current study was to evaluate the difference of alexithymia in OCD patients and healthy controls. This study was also designed to elucidate a specific link between certain OCD symptom dimensions and alexithymia. Forty-five patients with OCD and 45 healthy controls completed measures of the OCD symptom severity, alexithymia, anxiety, and depression. Patients with OCD had significantly higher scores of alexithymia than did the healthy controls. Multiple regression analysis revealed that age at onset and the level of anxiety were significantly associated with alexithymia. "Sexual/religious obsessions" was the only symptom dimension that showed a positive association with alexithymia in OCD patients. These findings suggest that OCD patients with a high level of anxiety and an early age of onset may have greater alexithymic tendency. We also found the first evidence for a specific link between sexual/religious obsessions and alexithymia in patients with OCD.

Mood-as-input hypothesis and perseverative psychopathologies

Mood-as-input hypothesis is a theory of task perseveration that has been applied to the understanding of perseveration across psychopathologies such as pathological worrying, compulsive checking, depressive rumination, and chronic pain. We review 10 years of published evidence from laboratory-based analogue studies and describe their relevance for perseveration in clinical populations. In particular, mood-as-input hypothesis predicts that perseveration at a task will be influenced by interactions between the individual's stop rules for the task and their concurrent mood, and that the valency of an individual's concurrent mood is used as information about whether the stop rule-defined goals for the task have been met. The majority of the published research is consistent with this hypothesis, and we provide evidence that clinical populations possess characteristics that would facilitate perseveration through mood-as-input processes. We argue that mood-as-input research on clinical populations is long overdue because (1) it has potential as a transdiagnostic mechanism helping to explain the development of perseveration and its comorbidity across a range of different psychopathologies, (2) it is potentially applicable to any psychopathology where perseveration is a defining feature of the symptoms, and (3) it has treatment implications for dealing with clinical perseveration.

Obsessive-compulsive disorder with and without bipolar disorder

AIM

Bipolar disorder (BD) is often comorbid with obsessive-compulsive disorder (OCD). In this study, we compared clinical profile and course of subjects with a primary diagnosis of OCD with and without BD.

METHODS

We compared 34 subjects with primary diagnosis of OCD with BD and 57 subjects with a diagnosis of OCD without BD. Structured interview schedules, clinical rating scales, and information from clinical charts were utilized to assess patients.

RESULTS

OCD with BD was characterized by: (i) an episodic course; (ii) a higher number of depressive episodes, greater suicidality and a higher rate of hospitalization; (iii) fewer pathological doubts and more miscellaneous compulsions; and (iv) poorer insight into obsessive-compulsive symptoms.

CONCLUSIONS

Episodic course appears to be typical of OCD with BD. Bipolarity has a pathoplastic effect on OCD and it is possible that some forms of OCD and BD are pathophysiologically related. Bipolar OCD is associated with a higher rate of depressive episodes, higher suicidality and more frequent hospitalizations, suggesting greater morbidity. Long-term prospective follow-up studies and studies addressing pathophysiology and genetic basis are needed to understand the complexity of such comorbidity.

Comorbid major depression in obsessive-compulsive disorder patients

Although major depressive disorder (MDD) has been consistently considered the most frequent complication of obsessive-compulsive disorder (OCD), little is known about the clinical characteristics of patients with both disorders. This study assessed 815 Brazilian OCD patients using a comprehensive psychiatric evaluation. Clinical and demographic variables, including OCD symptom dimensions, were compared among OCD patients with and without MDD. Our findings showed that prevalence rates of current MDD (32%) and lifetime MDD (67.5%) were similar for both sexes in this study. In addition, patients with comorbid MDD had higher severity scores of OCD symptoms. There was no preferential association of MDD with any particular OCD symptom dimension. This study supports the notion that depressed OCD patients present more severe general psychopathology.

Depression in relation to anxiety, obsessionality and phobia among neurosurgical patients with a primary brain tumor: a 1-year follow-up study

Depression is found to be present in up to 44% of brain tumor patients during their illness process. Anxiety as a comorbid psychiatric disorder with depression has formerly been studied, but phobia or obsessive-compulsive symptoms among brain tumor patients have not yet been noticed. By using a clinical prospective database of primary brain tumor patients (n=77) we studied the level of depression, anxiety, obsessionality (traits and symptoms) and phobic anxiety symptoms. Psychiatric symptoms were assessed before tumor operation as well as at three months and at one year after operation. The presence of comorbid anxiety, obsessionality and phobic anxiety symptoms was assessed before operation and at follow-ups in depressed and non-depressed patients, separately. Before tumor operation 16% of the patients had depression according to Beck Depression Inventory (BDI), while 10% had depression at three months and 15% at one year after operation. The depressed patients had statistically significantly higher anxiety scores and phobic scores at all three measurement points compared to corresponding scores among non-depressed brain tumor patients. The mean obsessionality scores among depressed brain tumor patients were significantly higher when measured before operation and at one year after the operation compared to non-depressed patients. To our knowledge, this is the first study so far in which comorbidity of psychiatric symptoms has been shown among depressive brain tumor patients. Concurrent comorbid conditions have been shown to be associated with increased severity, morbidity and chronicity of depression. It is recommended that treatment of depressive patients complicated with comorbid psychiatric disorders be planned by psychiatric units.

Can the neuroeconomics revolution revolutionize psychiatry?

Neuroeconomics is a rapidly growing new research discipline aimed at describing the neural substrate of decision-making using incentivized decisions introduced in experimental economics. The novel combination of economic decision theory and neuroscience has the potential to better examine the interactions of social, psychological and neural factors with regard to motivational forces that may underlie psychiatric problems. Game theory will provide psychiatry with computationally principled measures of cognitive dysfunction. Given the relatively high heritability of these measures, they may contribute to improving phenotypic definitions of psychiatric conditions. The game-theoretical concepts of optimal behavior will allow description of psychopathology as deviation from optimal functioning. Neuroeconomists have successfully used normative or near-normative models to interpret the function of neurotransmitters; these models have the potential to significantly improve neurotransmitter theories of psychiatric disorders. This paper will review recent evidence from neuroeconomics and psychiatry in support of applying economic concepts such as risk/uncertainty preference, time preference and social preference to psychiatric research to improve diagnostic classification, prevention and therapy.

Obsessive-compulsive spectrum disorders: still in search of the concept-affirming boundaries

PURPOSE OF REVIEW

Controversy exists about the diagnostic grouping of obsessive-compulsive spectrum disorders (OCSDs) - conditions that are to some extent related to obsessive-compulsive disorder (OCD). This review will re-examine OCSDs in light of the currently available evidence.

RECENT FINDINGS

It appears that OCSDs will not constitute a separate nosological group and, if this term is accepted, OCSDs may be grouped together with the anxiety disorders. Much needs to be done to refine the criteria for membership in the OCSDs. In contrast to previous proposals, only a few disorders may be included in the spectrum. The most likely candidates for membership are body dysmorphic disorder and hoarding disorder, if the latter becomes an independent condition. Mixed, but relatively strong, support for inclusion also exists for Tourette's disorder and trichotillomania.

SUMMARY

The concept of OCSDs is largely a product of an unbridled nosographical activity, resulting from a selective focus on the similar clinical features and an oversight of the important differences. While the links between some of the putative OCSDs seem important, the question remains as to whether the introduction of the spectrum to a diagnostic and classification system would significantly improve our understanding of these links.

Latent class analysis of the Yale-Brown Obsessive-Compulsive Scale symptoms in obsessive-compulsive disorder

OBJECTIVE

Obsessive-compulsive disorder (OCD) is phenomenologically heterogeneous, and findings of underlying structure classification based on symptom grouping have been ambiguous to date. Variable-centered approaches, primarily factor analysis, have been used to identify homogeneous groups of symptoms; but person-centered latent methods have seen little use. This study was designed to uncover sets of homogeneous groupings within 1611 individuals with OCD based on symptoms.

METHOD

Latent class analysis models using 61 obsessive-compulsive symptoms collected from the Yale-Brown Obsessive-Compulsive Scale were fit. Relationships between latent class membership and treatment response, sex, symptom severity, and comorbid tic disorders were tested for relationship to class membership.

RESULTS

Latent class analysis models of best fit yielded 3 classes. Classes differed only in frequency of symptom endorsement. Classes with higher symptom endorsement were associated with earlier age of onset, being male, higher Yale-Brown Obsessive-Compulsive Scale symptom severity scores, and comorbid tic disorders. There were no differences in treatment response between classes.

CONCLUSIONS

These results provide support for the validity of a single underlying latent OCD construct, in addition to the distinct symptom factors identified previously via factor analyses.

Nonverbal memory and organizational dysfunctions are related with distinct symptom dimensions in obsessive-compulsive disorder

Recent acceptance that obsessive-compulsive disorder (OCD) represents a heterogeneous phenomenon has underscored the need for dimensional approaches to this disorder. However little is known about the relation between neuropsychological functions and symptom dimensions. The purpose of this study was to identify the cognitive deficits correlated with specific symptom dimensions. Thirteen categories in the Yale-Brown Obsessive Compulsive Scale symptom checklist from 144 patients with OCD were analyzed by principal component analysis. Correlations between identified symptom dimensions and neuropsychological functioning, measured by the Boston Qualitative Scoring System, were analyzed. Five factors or dimensions were identified: contamination/cleaning, hoarding, symmetry/ordering, obsessions/checking, and repeating/counting. Dysfunctions in nonverbal memory and organizational strategies were related to the symmetry/ordering dimension and the obsessions/checking dimension, respectively. The results of the present study support a transculturally stable symptom structure for OCD. They also suggest the possibility that nonverbal memory dysfunction and organizational impairment are mediated by distinct obsessive-compulsive dimensions.

The clinical utility of symptom dimensions in obsessive-compulsive disorder

Factor analyses in obsessive-compulsive disorder (OCD) have consistently identified several different symptom dimensions. Nevertheless the clinical utility of identifying such symptom dimensions remains somewhat unclear. On the basis of their principal symptoms, 343 OCD patients were divided into four symptom dimension subgroups; 1) contamination/washing, 2) hoarding, 3) symmetry/repeating and ordering, and 4) forbidden thoughts/checking. Clinical variables including 1-year treatment outcome were compared across these patient subgroups. Most patients (74%) could distinctively be categorized as falling into a particular symptom subgroup. The groups were differentially characterized by some demographic and clinical features. For instance, both the symmetry and hoarding groups were significantly associated with decreased global functioning and greater OCD severity. Moreover the hoarding group was significantly more likely than the others to show longer duration of illness, lower rate of marriage, poor insight, and poorer outcome. However, about a quarter of the participants could not be classified definitively into a particular group. Our findings provide partial support for the clinical utility of a simple measure of symptom dimensions in OCD. In clinical settings, however, the limitations of such a simple measure of predominant symptom dimensions should be borne in mind and further work on their validity and utility is needed.

Quality of life and symptom dimensions of patients with obsessive-compulsive disorder

The aim of this study was to evaluate the impact of different dimensions of obsessive-compulsive symptoms, of co-morbid anxious depressive symptoms, and of sociodemographic characteristics on the quality of life of patients with obsessive-compulsive disorder (OCD). We evaluated 53 patients with OCD and 53 age- and gender-matched individuals from the community with a sociodemographic questionnaire, the Structured Clinical Interview for the Diagnosis of Diagnostic and Statistical Manual of Mental Disorders, fourth Edition, (DSM-IV), the Short-Form Health Survey-36 (SF-36), the Saving Inventory-Revised, the Obsessive-Compulsive Inventory-Revised, the Beck Depression Inventory and the Beck Anxiety Inventory. A series of stepwise linear regression analyses were performed, having the SF-36 dimensions as the dependent variables and the sociodemographic and clinical features as the independent ones. Patients with OCD displayed significantly lower levels of quality of life in all dimensions measured by the SF-36, except bodily pain. A model that included depressive symptoms, hoarding and employment status predicted 62% of the variance of the social functioning dimension of the quality of life of patients with OCD. Washing symptoms explained 31% of the variance of limitation due to physical health problems. Further, a series of models that included depressive, but not obsessive-compulsive symptoms, explained the remaining SF-36 dimensions. The severity of depressive and anxiety symptoms seems, therefore, to be powerful determinants of the level of quality of life in patients with OCD.

Obsessive-compulsive disorder and its related disorders: a reappraisal of obsessive-compulsive spectrum concepts

Obsessive-compulsive disorder (OCD) is a clinical syndrome whose hallmarks are excessive, anxiety-evoking thoughts and compulsive behaviors that are generally recognized as unreasonable, but which cause significant distress and impairment. When these are the exclusive symptoms, they constitute uncomplicated OCD. OCD may also occur in the context of other neuropsychiatric disorders, most commonly other anxiety and mood disorders. The question remains as to whether these combinations of disorders should be regarded as independent, cooccurring disorders or as different manifestations of an incompletely understood constellation of OCD spectrum disorders with a common etiology. Additional considerations are given here to two potential etiology-based subgroups: (i) an environmentally based group in which OCD occurs following apparent causal events such as streptococcal infections, brain injury, or atypical neuroleptic treatment; and (ii) a genomically based group in which OCD is related to chromosomal anomalies or specific genes. Considering the status of current research, the concept of OCD and OCD-related spectrum conditions seems fluid in 2010, and in need of ongoing reappraisal.

Obsessive-compulsive symptom dimensions in the general population: results from an epidemiological study in six European countries

BACKGROUND

The prevalence of obsessive-compulsive symptom dimensions and their sociodemographic and psychopathological correlates at the population level are unknown.

METHOD

Obsessive-compulsive symptom dimensions and mental disorders were assessed with the Composite International Diagnostic Interview 3.0 in a random subsample (n=2804) of individuals participating in a cross-sectional survey of the adult general population of six European countries.

RESULTS

The lifetime prevalence of any obsessive-compulsive symptom dimension was 13%. Harm/Checking was the most prevalent dimension (8%) followed by Somatic obsessions (5%) and Symmetry/Ordering (3%). Females were more likely to have symptoms in Contamination/Cleaning (OR=3, 95%CI=1.06-8.51) and Somatic obsessions (OR=1.88, 95%CI=1.05-3.37). All symptom dimensions were associated with an increased risk of most mental (but not physical) disorders. There were some differences in prevalence between countries.

LIMITATIONS

The interference associated with each symptom dimension could not be assessed. Few direct data are available on the validity of the CIDI to assess obsessive-compulsive symptom dimensions.

CONCLUSIONS

Obsessive-compulsive symptom dimensions are relatively frequent in the general population. Their sociodemographic and psychopathological correlates may be slightly different in clinical and community samples. They are associated with an increased risk of most mental disorders.

Suicide in patients treated for obsessive-compulsive disorder: a prospective follow-up study

BACKGROUND

To describe the occurrence of persistent suicidal ideation and suicide attempts in a sample of obsessive-compulsive patients followed-up prospectively during 1 to 6years, and to determine the existence of predictors of suicide behavior.

METHOD

Two hundred and eighteen outpatients with DSM-IV OCD, recruited from a specialized OCD Unit in Barcelona, Spain, between February 1998 and December 2007, were included in the study. Suicide ideation was assessed by item 3 of the Hamilton Depression Rating Scale. Suicide attempts were evaluated by the Beck Suicide Intent Scale. Patients with and without persistent suicidal thoughts and suicide attempters and non-attempters were compared on sociodemographic and clinical variables. A Cox proportional hazards regression analysis was used to estimate potential predictors of suicide.

RESULTS

Patients completed a mean follow-up period of treatment of 4.1years (SD: 1.7; range: 1-6years). During this period, eighteen patients (8.2%) reported persistent suicidal ideation, two patients (0.91%) committed suicide and 11 (5.0%) attempted suicide. Being unmarried, presenting higher basal scores in the HDRS, current or previous history of affective disorders and symmetry/ordering obsessions were independently associated with suicidal behaviors.

LIMITATIONS

Patients were recruited from a specialized OCD clinic and received exhaustive treatment. Influence of variables including social support, life events, hopelessness and substance abuse/dependence was not assessed.

CONCLUSIONS

Suicide behavior is not a highly common phenomenon in OCD, but it should not be disregarded, especially in unmarried patients, with comorbid depression and symmetry/ordering obsessions and compulsions, who appear to be at a greater risk for suicide acts.

Obsessive-compulsive disorder: a review of the diagnostic criteria and possible subtypes and dimensional specifiers for DSM-V

BACKGROUND

Since the publication of the DSM-IV in 1994, research on obsessive-compulsive disorder (OCD) has continued to expand. It is timely to reconsider the nosology of this disorder, assessing whether changes to diagnostic criteria as well as subtypes and specifiers may improve diagnostic validity and clinical utility.

METHODS

The existing criteria were evaluated. Key issues were identified. Electronic databases of PubMed, ScienceDirect, and PsycINFO were searched for relevant studies.

RESULTS

This review presents a number of options and preliminary recommendations to be considered for DSM-V. These include: (1) clarifying and simplifying the definition of obsessions and compulsions (criterion A); (2) possibly deleting the requirement that people recognize that their obsessions or compulsions are excessive or unreasonable (criterion B); (3) rethinking the clinical significance criterion (criterion C) and, in the interim, possibly adjusting what is considered "time-consuming" for OCD; (4) listing additional disorders to help with the differential diagnosis (criterion D); (5) rethinking the medical exclusion criterion (criterion E) and clarifying what is meant by a "general medical condition"; (6) revising the specifiers (i.e., clarifying that OCD can involve a range of insight, in addition to "poor insight," and adding "tic-related OCD"); and (7) highlighting in the DSM-V text important clinical features of OCD that are not currently mentioned in the criteria (e.g., the major symptom dimensions).

CONCLUSIONS

A number of changes to the existing diagnostic criteria for OCD are proposed. These proposed criteria may change as the DSM-V process progresses.

Obsessive-compulsive symptom dimensions in Japanese tourette syndrome subjects

OBJECTIVES

To investigate the current and lifetime frequency and severity of obsessive-compulsive (OC) symptom dimensions in Tourette syndrome (TS) patients, and how these dimensions affect clinical characteristics.

METHODS

Forty TS outpatients (29 males, 11 females) were interviewed with the Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS), the Yale Global Tic Severity Scale (YGTSS), the Shapiro Tourette Syndrome Severity Scale, and the Global Assessment of Functioning (GAF).

RESULTS

OC symptoms were present in 80% of the total sample. The miscellaneous and the symmetry dimensions were the most frequent at the "current" and "lifetime" surveys, respectively. The aggression dimension had the smallest difference between "worst ever" and current ratings among the all OC symptom dimensions. TS patients with the aggression dimension (n=7) had significantly lower scores in the GAF scale and higher frequencies of coprolalia. There were significant correlations between the YGTSS severity scores and specific DY-BOCS dimensions.

CONCLUSION

OC symptoms are frequent in TS subjects and there were differences in the frequency, severity, and course of the OC symptom dimensions. These results emphasize the need for future longitudinal studies using a dimensional approach for the evaluation of OC symptoms in tic disorders.

Eating disorders in patients with obsessive-compulsive disorder: prevalence and clinical correlates

OBJECTIVE

The objective is to evaluate the prevalence and associated clinical characteristics of eating disorders (ED) in patients with obsessive-compulsive disorder (OCD).

METHOD

This is a cross-sectional study comparing 815 patients with OCD. Participants were assessed with structured interviews and scales: SCID-I, Y-BOCS, Dimensional Y-BOCS, BABS, Beck Depression and Anxiety Inventories.

RESULTS

Ninety-two patients (11.3%) presented the following EDs: binge-eating disorders [= 59 (7.2%)], bulimia nervosa [= 16 (2.0%)], or anorexia nervosa [= 17 (2.1%)]. Compared to OCD patients without ED (OCD-Non-ED), OCD-ED patients were more likely to be women with previous psychiatric treatment. Mean total scores in Y-BOCS, Dimensional Y-BOCS, and BABS were similar within groups. However, OCD-ED patients showed higher lifetime prevalence of comorbid conditions, higher anxiety and depression scores, and higher frequency of suicide attempts than did the OCD-Non-ED group. Primarily diagnosed OCD patients with comorbid ED may be associated with higher clinical severity.

DISCUSSION

Future longitudinal studies should investigate dimensional correlations between OCD and ED.

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.

Clinical and cognitive correlates of depressive symptoms among youth with obsessive compulsive disorder

Depression is the most common comorbidity among adults with obsessive compulsive disorder (OCD), yet little is known about depressive symptoms in childhood OCD. This study examined clinical and cognitive variables associated with depressive symptomatology in 71 youths (62% male, M age = 12.7 years) with primary OCD. Youths presented with a range of depressive symptoms, with 21% scoring at or above the clinical cutoff on the self-report measure of depression. Higher levels of depressive symptoms were associated with higher levels of cognitive distortions assessed on measures of insight, perceived control, competence, and contingencies. Depressive symptoms were also linked to older age and more severe OCD. Low perceived control and self-competence and high OCD severity independently predicted depression scores.

Tourette's syndrome, trichotillomania, and obsessive-compulsive disorder: how closely are they related?

The question of whether Tourette's syndrome (TS) and trichotillomania (TTM) are best conceptualized as obsessive-compulsive spectrum disorders was raised by family studies demonstrating a close relationship between TS and obsessive-compulsive disorder (OCD), and by psychopharmacological research indicating that both TTM and OCD respond more robustly to clomipramine than to desipramine. A range of studies have subsequently allowed comparison of the phenomenology, psychobiology, and management of TS and TTM, with that of OCD. Here we briefly review this literature. The data indicate that there is significant psychobiological overlap between TS and OCD, supporting the idea that TS can be conceptualized as an OCD spectrum disorder. TTM and OCD have only partial overlap in their phenomenology and psychobiology, but there are a number of reasons for why it may be useful to classify TTM and other habit disorders as part of the obsessive-compulsive spectrum of disorders.

Predictors of early adult outcomes in pediatric-onset obsessive-compulsive disorder

OBJECTIVE

The aim of this study was to determine the childhood clinical predictors of early adult outcomes in pediatric-onset obsessive-compulsive disorder (OCD) and to assess whether dimensional subtypes of OCD and the presence of comorbid tic symptoms influence long-term outcomes.

METHODS

We conducted a longitudinal cohort study in which 45 of 62 eligible children with OCD were reassessed an average of 9 years later, in early adulthood. Main outcome measures included expert-rated, obsessive-compulsive (OC) symptom severity and time to remission of OC symptoms. Baseline clinical characteristics were evaluated in terms of their influence on OCD severity in adulthood and time to remission of OC symptoms.

RESULTS

Forty-four percent of subjects were determined to have subclinical OC symptoms at the follow-up evaluation. The absence of a comorbid tic disorder and the presence of prominent hoarding symptoms were associated with the persistence of OCD symptoms. Female gender, earlier age at childhood assessment, later age of OCD onset, more-severe childhood OCD symptoms, and comorbid oppositional defiant disorder also were associated with persistence of OCD symptoms into adulthood.

CONCLUSIONS

These results confirm that a significant proportion of treated children with OCD experience remission by adulthood. The presence of comorbid tics heralds a positive outcome, whereas primary hoarding symptoms are associated with persistent OCD.

Obsessive-compulsive disorder: subclassification based on co-morbidity

BACKGROUND

Obsessive-compulsive disorder (OCD) is probably an etiologically heterogeneous condition. Many patients manifest other psychiatric syndromes. This study investigated the relationship between OCD and co-morbid conditions to identify subtypes.

METHOD

Seven hundred and six individuals with OCD were assessed in the OCD Collaborative Genetics Study (OCGS). Multi-level latent class analysis was conducted based on the presence of eight co-morbid psychiatric conditions [generalized anxiety disorder (GAD), major depression, panic disorder (PD), separation anxiety disorder (SAD), tics, mania, somatization disorders (Som) and grooming disorders (GrD)]. The relationship of the derived classes to specific clinical characteristics was investigated.

RESULTS

Two and three classes of OCD syndromes emerge from the analyses. The two-class solution describes lesser and greater co-morbidity classes and the more descriptive three-class solution is characterized by: (1) an OCD simplex class, in which major depressive disorder (MDD) is the most frequent additional disorder; (2) an OCD co-morbid tic-related class, in which tics are prominent and affective syndromes are considerably rarer; and (3) an OCD co-morbid affective-related class in which PD and affective syndromes are highly represented. The OCD co-morbid tic-related class is predominantly male and characterized by high conscientiousness. The OCD co-morbid affective-related class is predominantly female, has a young age at onset, obsessive-compulsive personality disorder (OCPD) features, high scores on the 'taboo' factor of OCD symptoms, and low conscientiousness.

CONCLUSIONS

OCD can be classified into three classes based on co-morbidity. Membership within a class is differentially associated with other clinical characteristics. These classes, if replicated, should have important implications for research and clinical endeavors.

Measuring obsessive-compulsive symptoms: Padua Inventory-Revised vs. Yale-Brown Obsessive Compulsive Scale

Although the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Padua Inventory-Revised (PI-R) are the most widely used instruments for assessing presence and severity of symptoms in obsessive-compulsive disorder (OCD), the correlation between the two instruments is surprisingly low. The aim of the present investigation was to test two possible explanations for the discrepancy between these instruments by comparing both scales in 120 OCD patients. The tested hypotheses included: (1) differences in the way the measures are administered, i.e. observer-rated vs. self-rated; and (2) differences in the way severity is calculated, i.e. the PI-R measures severity by aggregating symptoms, while the Y-BOCS measures severity unrelated to the number of symptoms. Results indicated that neither hypothesis satisfactorily explains the differences between the measures. The investigation concludes that the Y-BOCS and PI-R measure relatively unrelated features of OCD, and the combined use of multiple measures is recommended to assess the complexity of OCD phenomena.

Sub-clinical compulsive checkers show impaired performance on habitual, event- and time-cued episodic prospective memory tasks

This study focused on examining whether sub-clinical checkers perform worse on a behavioral measure of habitual prospective memory, and on uncovering the source of a dissociation we previously reported between sub-clinical checkers' performance on event- and time-cued episodic prospective memory tasks [Cuttler, C., & Graf, P. (2007). Sub-clinical compulsive checkers' prospective memory is impaired. Journal of Anxiety Disorders, 21(3), 338-352]. Undergraduate students were assigned a habitual prospective memory task, an event-cued and a time-cued episodic prospective memory task, and they completed questionnaires designed to assess problems with prospective memory in everyday life. Compared to low checkers, high checkers demonstrated higher failure rates on the habitual, event- and time-cued episodic prospective memory tasks, and reported more frequent failures of prospective memory in everyday life. The results showed that the previously reported dissociation was an artifact of the method used for scoring time-cued prospective memory. Our results lend support to the theory that a deficit in prospective memory contributes to the development and maintenance of checking compulsions.

A haplotype containing quantitative trait loci for SLC1A1 gene expression and its association with obsessive-compulsive disorder

CONTEXT

Recent evidence from linkage analyses and follow-up candidate gene studies supports the involvement of SLC1A1, which encodes the neuronal glutamate transporter, in the development of obsessive-compulsive disorder (OCD).

OBJECTIVES

To determine the role of genetic variation of SLC1A1 in OCD in a large case-control study and to better understand how SLC1A1 variation affects functionality.

DESIGN

A case-control study.

SETTING

Publicly accessible SLC1A1 expression and genotype data.

PATIENTS

Three hundred twenty-five OCD probands and 662 ethnically and sex-matched controls.

INTERVENTIONS

Probands were assessed with the Structured Clinical Interview for DSM-IV, the Yale-Brown Obsessive Compulsive Scale, and the Saving Inventory-Revised. Six single-nucleotide polymorphisms (SNPs) were genotyped. Multiple testing corrections for single-marker and haplotype analyses were performed by permutation.

RESULTS

Gene expression of SLC1A1 is heritable in lymphoblastoid cell lines. We identified 3 SNPs in or near SLC1A1 that correlated with gene expression levels, 1 of which had previously been associated with OCD. Two of these SNPs also predicted expression levels in human brain tissue, and 1 SNP was further functional in reporter gene studies. Two haplotypes at 3 SNPs, rs3087879, rs301430, and rs7858819, were significantly associated with OCD after multiple-testing correction and contained 2 SNPs associated with expression levels. In addition, another SNP correlating with SLC1A1 gene expression, rs3933331, was associated with an OCD-hoarding subphenotype as assessed by 2 independent, validated scales.

CONCLUSIONS

Our case-control data corroborate previous smaller family-based studies that indicated that SLC1A1 is a susceptibility locus for OCD. The expression and genotype database-mining approach we used provides a potentially useful complementary approach to strengthen future candidate gene studies in neuropsychiatric and other disorders.

Obsessions and compulsions in the community: prevalence, interference, help-seeking, developmental stability, and co-occurring psychiatric conditions

OBJECTIVE

It is unclear how many people in the community have obsessions and compulsions and associated levels of interference. It is also unknown what variables predict help-seeking for these symptoms, whether they are developmentally stable, and whether they increase the risk of mental disorders.

METHOD

The authors analyzed data from the prospective longitudinal Dunedin study of an unselected birth cohort. The presence of obsessions and compulsions and mental disorders was assessed using the Diagnostic Interview Schedule (DIS) at ages 11, 26, and 32. Data on interference and help-seeking were obtained at ages 26 and 32.

RESULTS

Obsessions and compulsions were frequent in individuals with mental disorders other than obsessive-compulsive disorder (OCD) and among people without mental disorders. Even in the latter group, these symptoms caused significant interference. The presence of anxiety/depression and of obsessions (particularly aggressive and shameful thoughts), but not compulsions, was associated with help-seeking. Harm/checking was the most prevalent symptom dimension. Symptom dimensions were temporally stable and associated with increased comorbidity. Obsessive-compulsive symptoms at age 11 predicted a high risk of an adult OCD diagnosis as well as elevated adult symptom dimensions.

CONCLUSIONS

Obsessions and compulsions are common in the adult population, have their roots in childhood, and are associated with interference, risk for disorders, and help-seeking. Subclinical obsessions and compulsions should be taken into account in research, intervention, and DSM-V.

Eating disorders and obsessive-compulsive disorder: A dimensional approach to purported relations

The purpose of this research was to investigate the specificity of purported relations between symptoms of eating disorders (ED) and obsessive-compulsive disorder (OCD). Whereas most research has focused on diagnostic comorbidity or between-groups analyses, this study took a dimensional approach to investigate specific relations among symptoms of anorexia, bulimia, and OCD, as well as panic, depression, and general distress in a student sample (N=465). Results were that all symptoms showed significant zero-order correlations, including all ED-OCD pairings. After removing general distress variance, however, none of three OCD scales significantly predicted anorexia; only compulsive washing among OCD scales significantly predicted bulimia. Hierarchical multiple regression demonstrated that panic and depression out-performed OCD in predicting bulimia symptoms. Overall, symptoms of ED and OCD did not show unique relations at the level of core dimensions of each construct. A possible link between bulimia and compulsive washing is worth further study.

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.

The major symptom dimensions of obsessive-compulsive disorder are mediated by partially distinct neural systems

Obsessive-compulsive disorder (OCD) is a clinically heterogeneous disorder characterized by multiple, temporally stable symptom dimensions. Preliminary functional neuroimaging studies suggest that these symptom dimensions may have distinct neural substrates. Whole-brain voxel-based morphometry was used to examine the common and distinct neuroanatomical (structural) substrates of the major symptom dimensions of OCD. First, we compared 55 medication-free patients with OCD and 50 age-matched healthy control subjects. Multiple regression analyses were then used to examine the relationship between global and regional grey matter (GM) and white matter (WM) volumes and symptom dimension scores within the patient group. OCD patients showed decreased GM volume in left lateral orbitofrontal (BA47), left inferior frontal (BA44/45), left dorsolateral prefrontal (BA9) and right medial prefrontal (BA10) cortices and decreased bilateral prefrontal WM volume. Scores on the 'symmetry/ordering' dimension were negatively correlated with 'global' GM and WM volumes. Scores on the 'contamination/washing' dimension were negatively correlated with 'regional' GM volume in bilateral caudate nucleus and WM volume in right parietal region. Scores on the 'harm/checking' dimension were negatively correlated with regional GM and WM volume in bilateral temporal lobes. Scores on the 'symmetry/ordering' dimension were negatively correlated with regional GM volume in right motor cortex, left insula and left parietal cortex and positively correlated with bilateral temporal GM and WM volume. The results remained significant after controlling for age, sex, educational level, overall illness severity, global WM and GM volumes and excluding patients with comorbid depression. The reported symptom dimension-specific GM and WM alterations support the hypothesis that OCD is an etiologically heterogeneous disorder, with both overlapping and distinct neural correlates across symptom dimensions. These results have clear implications for the current neuroanatomical model of OCD and call for a substantial revision of such model which takes into account the heterogeneity of the disorder.

Four-factor structure of obsessive-compulsive disorder symptoms in children, adolescents, and adults

OBJECTIVE

To determine whether the four-factor category-based obsessive-compulsive disorder (OCD) symptom structure from a previous confirmatory factor analysis (CFA) may be appropriately used in child, adolescent, and adult groups. Symptom dimensions are increasingly used as quantitative traits in genetic, neuroimaging, and treatment studies of OCD across all ages. Identification of a category-based OCD symptom dimension structure that is validated for use across child, adolescent, and adult age groups is necessary to guide ongoing translational research.

METHOD

Four OCD samples comprising 356 individuals were divided into child, adolescent, and adult groups. The fit of the only CFA-defined four-factor model was compared across these independent age group samples. Multiple-group CFA using maximum likelihood estimation assessed adequacy of fit comparing unconstrained and measurement weight-constrained models. The fit of previous exploratory factor analysis-defined three- and five-factor models on adults was also examined using CFA.

RESULTS

A four-factor solution provided adequate but imperfect fit across age groups, with comparable indices to the only previous OCD CFA: factor 1 (aggressive/sexual/religious/somatic/checking); factor 2 (symmetry/ordering/counting/repeating); factor 3 (contamination/cleaning), and factor 4 (hoarding). Models in which factor loadings were constrained and unconstrained across the three age groups yielded comparable model fit. Factors were highly correlated and were not mutually exclusive. The four-factor solution provided an improved fit to both three- and five-factor solutions using CFA across the three age groups.

CONCLUSIONS

A four-factor, CFA-defined, category-based model of OCD symptom dimensions is adequate for use in children, adolescents, and adult age groups. The factor structure of this multiple age group sample has limitations and is imperfect, but current findings support the comparability of the defined latent OCD dimensions across age groups. Further work is needed to optimize a comprehensive symptom dimension model reflecting clinical heterogeneity for use in emergent translational studies.

SERT Ileu425Val in autism, Asperger syndrome and obsessive-compulsive disorder

BACKGROUND

SERT I425V, an uncommon missense single nucleotide polymorphism producing a gain-of-function of the serotonin transporter (SERT), was originally found to segregate with a primarily obsessive-compulsive disorder (OCD) but complexly comorbid phenotype in two unrelated families.

OBJECTIVE

As two individuals with SERT I425V and OCD also had Asperger syndrome (AS), an autism spectrum disorder, and as other rare SERT variants have recently shown significant associations with autism, we set out to extend our original OCD study by genotyping additional autism/AS and OCD samples.

METHODS

Case-control association study of SERT I425V in 210 AS/autism probands and 215 controls, plus 335 OCD probands and their family members.

RESULTS

SERT I425V was not found in any of the individuals with AS/autism, OCD alone or OCD comorbid with AS and other disorders, or in controls. This results in new estimates of SERT I425V having a 1.5% prevalence in 530 individuals with OCD from five unrelated families genotyped by us and by one other group and a 0.23% frequency in four control populations totaling 1300 individuals, yielding a continuing significant OCD-control difference (Fisher's exact test corrected for family coefficient of identity P=0.004, odds ratio=6.54).

CONCLUSION

As several other uncommon, less well quantitated genetic variations occur with an OCD phenotype, including chromosomal anomalies and some other rare gene variants (SGCE, GCH1 and SLITRK1), a tentative conclusion is that OCD resembles other complex disorders in being etiologically heterogeneous and in having both highly penetrant familial subtypes associated with rare alleles or chromosomal anomalies, as well as having a more common, polygenetic form that may involve polymorphisms in such genes as BDNF, COMT, GRIN2beta, TPH2, HTR2A and SLC1A1.

Sub-clinical checking compulsions are related to impaired prospective memory independently of depression, anxiety and distractibility

In this study, we explored whether relationships between checking compulsions and prospective memory are a result of the increased levels of distractibility, depression, state and trait anxiety associated with checking compulsions. Students (N=126) completed a prospective memory task and questionnaires which assess the frequency of experiencing prospective memory failures. Checking compulsions were associated with failing the prospective memory task and with self-reported prospective memory failures. Elevations in distractibility, depression, state and trait anxiety associated with checking compulsions had no influence on prospective memory task performance. They contributed to, but did not completely account for, the relationship between checking and self-reported prospective memory. The results support our theory that individuals with checking compulsions have an impaired prospective memory and that their increased experiences with prospective memory failures undermines their trust in the ability to perform tasks, ultimately resulting in intrusive doubts that specific tasks were not performed and the compulsion to check.

Early-onset obsessive-compulsive disorder and personality disorders in adulthood

Obsessive-compulsive disorder (OCD) often emerges in childhood or adolescence. The aim of the present study was to evaluate whether adult patients with prepuberal onset differ from subjects with later onset in terms of personality disorder comorbidity. The Structured Clinical Interview for DSM-IV Axis II Disorders was used to assess 148 patients with a principal diagnosis of OCD according to the Structured Clinical Interview for DSM-IV Axis I Disorders. The following two subgroups of subjects were selected according to the age at onset of symptomatology: patients with an early-onset (< or =10 years), and patients with a later onset (> or =17 years). Of the 148 patients screened for the present study, 33 (22.3%) had an early onset and 1369 (46.6%) had a later onset. With regard to personality disorders, early-onset patients showed more OC personality disorders (OCPD) than later onset patients. Our finding suggests that OCD in childhood increases the risk for developing OCPD in adulthood, or that early-onset OCD and OCPD share a common pathogenesis.

Predicting genetic loading from symptom patterns in obsessive- compulsive disorder: a latent variable analysis

BACKGROUND

Some symptom dimensions in obsessive-compulsive disorder (OCD) patients have a familial and putative genetic foundation, based on replicated findings in studies of sib-pairs with OCD. However, these symptom dimensions are all from exploratory factor analyses of Yale-Brown Obsessive-Compulsive Scale Symptom Checklist ratings based on non-empirically derived symptom categories, rather than individual symptoms.

METHODS

In this study, we used a novel latent variable mixture model analysis to identify meaningful patient subgroupings. This was preceded by a confirmatory factor analysis of a 65-item OCD symptom inventory from 398 OCD probands, which yielded a five-factor solution. Data from all five symptom factors were used in a latent variable mixture model analysis, which identified two statistically separate OCD subpopulations.

RESULTS

One group of probands had a significantly higher proportion of OCD-affected afflicted relatives (parents or close parental relatives), whereas the other group had a less prevalent familial OCD. The group with the more familial OCD was also found to have an earlier age of OCD onset, more severe OCD symptoms, and greater psychiatric comorbidity and impairment.

CONCLUSIONS

Especially if the results are verified in other samples, this research paradigm, which identified characteristics of individuals with familial OCD, should prove useful in carrying out genome-wide linkage and association studies of OCD and may provide a model for other symptom-based studies of additional medical disorders.

Characterizing the hoarding phenotype in individuals with OCD: associations with comorbidity, severity and gender

Hoarding frequently occurs in obsessive-compulsive disorder (OCD), and some evidence suggests that it constitutes a distinct OCD subtype, with genetic contributions. This study investigated differences between OCD patients with and without hoarding symptoms. Of the 473 OCD patients studied, 24% were classified as hoarders according to combined interviewer and self-ratings, which were validated with the Savings Inventory-Revised in a subsample. Hoarders suffered from significantly more severe OCD symptoms, (especially compulsions) and had greater impairment and dysphoria. Hoarders also had more comorbid psychiatric disorders. Further study revealed that many of these differences were attributable to the female subjects: Compared to female non-hoarders, female hoarders were more likely to suffer from bipolar I, substance abuse, panic disorder, binge-eating disorder, and had greater OCD severity. Male hoarders had an increased prevalence of social phobia compared to non-hoarding males. These results suggest that there are gender-specific differences in the hoarding sub-phenotype of OCD.

A large case-control study of common functional SLC6A4 and BDNF variants in obsessive-compulsive disorder

Both serotonin transporter (SLC6A4) and brain-derived neurotrophic factor (BDNF) genes have shown positive associations with obsessive-compulsive disorder (OCD) and some other psychiatric disorders, but these results have not been consistently replicated. To explore the hypothesis that this variability might result from the effects of differing combinations of overlooked variants within SLC6A4 together with small OCD and control sample sizes, we studied three common functional polymorphisms (5-HTTLPR, STin2, and the newly discovered SNP, rs25531) in the largest sample size of OCD patients (N=347) and controls (N=749) ever investigated. During methods development, we found evidence for potential SLC6A4 genotyping problems with earlier methodology, a third possible contributor to variability in earlier studies. A fourth possible explanation might be SLC6A4 x BDNF interactions, which prompted us to investigate combined genotypes of BDNF V66M with the three SLC6A4 loci. Except for a nominal association with rs25531 alone, which did not survive correction for multiple comparisons, we found no evidence for any of these other variants being associated alone or together with OCD, and we therefore also examined clinical OCD subtypes within the sample to evaluate clinical heterogeneity. Subgroups based on the age of OCD onset, gender, familiality, factor analysis-derived symptom dimensions, or comorbidity with other psychiatric disorders failed to identify SLC6A4- or BDNF-associated phenotypes, with one exception of overall number of comorbid anxiety disorders being significantly associated with 5-HTTLPR/rs25531. We conclude that despite their attractiveness as candidate genes in OCD, our data provide no support for association in this large OCD patient sample and point toward the need to examine other genes as candidates for risk determinants in OCD.