Use of factor-analyzed symptom dimensions to predict outcome with serotonin reuptake inhibitors and placebo in the treatment of obsessive-compulsive disorder

Waitlist-controlled trial of cognitive behavior therapy for hoarding disorder

OBJECTIVE

This study investigated a multicomponent cognitive behavioral treatment (CBT) for hoarding based on a model proposed by Frost and colleagues and manualized in Steketee and Frost (2007).

METHOD

Participants with clinically significant hoarding were recruited from the community and a university-based anxiety clinic. Of the 46 patients randomly assigned to CBT or waitlist (WL), 40 completed the 12-week assessment and 36 completed 26 sessions. Treatment included education and case formulation, motivational interviewing, skills training for organizing and problem solving, direct exposure to nonacquiring and discarding, and cognitive therapy. Measures included the Saving Inventory-Revised (self-report), Hoarding Rating Scale-Interview, and measures of clinical global improvement. Between group repeated measures analyses using general linear modeling examined the effect of CBT versus WL on hoarding symptoms and moodstate after 12 weeks. Within group analyses examined pre-post effects for all CBT participants combined after 26 sessions.

RESULTS

After 12 weeks, CBT participants benefited significantly more than WL patients on hoarding severity and mood with moderate effect sizes. After 26 sessions of CBT, participants showed significant reductions in hoarding symptoms with large effect sizes for most measures. At session 26, 71% of patients were considered improved on therapist clinical global improvement ratings and 81% of patients rated themselves improved; 41% of completers were clinically significantly improved.

CONCLUSIONS

Multicomponent CBT was effective in treating hoarding. However, treatment refusal and compliance remain a concern, and further research with independent assessors is needed to establish treatment benefits and durability of gains.

Symptom dimensions in Chinese patients with obsessive-compulsive disorder

To study the symptom dimensions of Chinese patients with obsessive-compulsive disorder (OCD), the symptom checklist of the Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS) was used to assess the symptom dimensions of 139 OCD patients at a mental health center in Shanghai. The most common symptom dimensions were symmetry (67.6%), contamination (43.2%), and aggression (31.7%). The frequency of patients with the miscellaneous, sexual/religious, and hoarding symptom dimensions was 25.9%, 10.8%, and 8.6%, respectively. The frequency of male patients with symmetry concerns was higher than that of the female patients, and the frequency of female patients with contamination concerns was higher than that of male patients. OCD symptom dimensions can be identified in the Chinese context but there is a low frequency of endorsement of certain dimensions: sexual/religious, aggression, and hoarding concerns. Future studies need to further investigate the sociocultural and gender factors that may result in these findings: low numbers of people in China with a religious affiliation and the Chinese emphasis on Confucian harmony philosophy, thrift, and saving.

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.

Genetics of obsessive-compulsive disorder

Obsessive-compulsive disorder is a common debilitating condition affecting individuals from childhood through adult life. There is good evidence of genetic contribution to its etiology, but environmental risk factors also are likely to be involved. The condition probably has a complex pattern of inheritance. Molecular studies have identified several potentially relevant genes, but much additional research is needed to establish definitive causes of the condition.

Dimensional predictors of response to SRI pharmacotherapy in obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is clinically heterogeneous. Previous studies have reported different patterns of treatment response to serotonin reuptake inhibitors (SRI) based on symptom dimension. Our objective was to replicate these results in OCD patients who participated in one of four randomized, placebo-controlled, clinical trials (RCT).

METHODS

A total of 165 adult OCD subjects participated in one or more eight-week RCT with clomipramine, fluvoxamine, or fluoxetine. All subjects were classified as having major or minor symptoms in four specific OC symptom dimensions that were derived in a previous factor analytic study involving many of these same patients. Ordinal logistic regression was used to test the association between OC symptom dimensions and SRI response.

RESULTS

We found a significant association between the symptom dimension involving sexual, religious and harm-related obsessions as well as checking compulsions (AGG/SR) and improved SRI response. This increased rate of SRI response was experienced primarily by individuals with harm-related obsessions. Over 60% of patients with AGG/SR OCD symptoms were rated as very much improved after SRI treatment.

LIMITATIONS

As some of the RCTs included were conducted prior to the development of the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), improvement in OCD severity was assessed using the Clinical Global Improvement (CGI) Scale. Data from the double-blind and open-label continuation phases of these trials was collapsed together to increase statistical power.

CONCLUSIONS

Patients with OCD vary in their response to SRIs. The presence of AGG/SR symptoms is associated with an initial positive response to SRIs. These data add to the growing body of work linking central serotonin systems with aggressive behavior.

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.

Symptom dimensions and subtypes of obsessive-compulsive disorder: a developmental perspective

In the absence of definitive etiological markers for obsessive-compulsive disorder (OCD% obsessive-compulsive (OC) symptom dimensions may offer a fruitful point of orientation. These dimensions can be understood as defining potentially overlapping clinical features that may be continuous with "normal" worries first evident in childhood. Although the understanding of the dimensional structure of OC symptoms is still imperfect, a recent large-scale meta-analysis has confirmed the presence of at least four separa ble symptom dimensions in children, as well as adults, with OCD. A dimensional approach does not exclude other methods to parse OCD. Thus far, a pediatric age of onset, the presence of other family members with OCD, and the individual's "tic-related" status appear to be potentially useful categorical distinctions. Although the OC symptom dimensions appear to be valid for all ages, it is unlikely that the underlying genetic vulnerability factors and neurobiological substrates for each of these symptom dimensions are the same across the course of development.

Sequential allocation to balance prognostic factors in a psychiatric clinical trial

OBJECTIVE

This paper aims to describe and discuss a minimization procedure specifically designed for a clinical trial that evaluates treatment efficacy for OCD patients.

METHOD

Aitchison's compositional distance was used to calculate vectors for each possibility of allocation in a covariate adaptive method. Two different procedures were designed to allocate patients in small blocks or sequentially one-by-one.

RESULTS

We present partial results of this allocation procedure as well as simulated data. In the clinical trial for which this procedure was developed, successful balancing between treatment arms was achieved. Separately, in an exploratory analysis, we found that if the arrival order of patients was altered, most patients were allocated to a different treatment arm than their original assignment.

CONCLUSION

Our results show that the random arrival order of patients determine different assignments and therefore maintains the unpredictability of the allocation method. We conclude that our proposed procedure allows for the use of a large number of prognostic factors in a given allocation decision. Our method seems adequate for the design of the psychiatric trials used as models. Trial registrations are available at clinicaltrials.gov NCT00466609 and NCT00680602.

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.

Gray matter structural alterations in obsessive-compulsive disorder: relationship to neuropsychological functions

Numerous magnetic resonance (MR) studies have examined gray matter structural alterations in patients with obsessive-compulsive disorder (OCD). Few, however, have used automated, highly reliable techniques such as voxel-based morphometry (VBM) to examine the entire brain in contrast to selected regions of interest. Moreover, few studies have examined the functional correlates of gray matter abnormalities in OCD. We used VBM to evaluate regional gray matter differences between 21 OCD patients and 21 age- and sex-matched healthy volunteers. All patients had comprehensive neuropsychological assessments. MR images were normalized to a customized template and segmented using optimized VBM. OCD patients had significantly more gray matter in the left thalamus compared with healthy volunteers. OCD patients without major depression had significantly more gray matter in the thalamus (bilaterally) and left orbitofrontal cortex as well as an unpredicted region of more right dorsolateral prefrontal gray matter, which remained significant after correction for multiple comparisons, compared with healthy volunteers. In the subgroup of patients without depression, greater right hemisphere thalamic and dorsolateral prefrontal gray matter correlated significantly with worse motor functioning and processing speed, respectively. In this subgroup there was also a tendency for more gray matter in the left orbitofrontal cortex and right dorsolateral prefrontal cortex to be associated with greater symptom severity. Our findings provide additional support for the involvement of cortical-striatal-thalamic circuits in the pathophysiology of OCD and preliminary evidence that a defect involving the dorsolateral prefrontal cortex may also be implicated. Moreover, our data suggest that gray matter structural alterations in OCD have neuropsychological correlates, which may be useful in further characterizing structure-function relations in this disorder.

Further development of YBOCS dimensions in the OCD Collaborative Genetics study: symptoms vs. categories

Despite progress in identifying homogeneous subphenotypes of obsessive-compulsive disorder (OCD) through factor analysis of the Yale Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC), prior solutions have been limited by a reliance on presupposed symptom categories rather than discrete symptoms. Furthermore, there have been few attempts to evaluate the familiality of OCD symptom dimensions. The purpose of this study was to extend prior work by this collaborative group in category-based dimensions by conducting the first-ever exploratory dichotomous factor analysis using individual OCD symptoms, comparing these results to a refined category-level solution, and testing the familiality of derived factors. Participants were 485 adults in the six-site OCD Collaborative Genetics Study, diagnosed with lifetime OCD using semi-structured interviews. YBOCS-SC data were factor analyzed at both the individual item and symptom category levels. Factor score intraclass correlations were calculated using a subsample of 145 independent affected sib pairs. The item- and category-level factor analyses yielded nearly identical 5-factor solutions. While significant sib-sib associations were found for four of the five factors, Hoarding and Taboo Thoughts were the most robustly familial (r ICC>or=0.2). This report presents considerable converging evidence for a five-factor structural model of OCD symptoms, including separate factor analyses employing individual symptoms and symptom categories, as well as sibling concordance. The results support investigation of this multidimensional model in OCD genetic linkage studies.

Sex-specific clinical correlates of hoarding in obsessive-compulsive disorder

Little is known about whether the clinical correlates of hoarding behavior are different in men and women with obsessive-compulsive disorder (OCD). In the current study, we evaluated the association of hoarding with categories of obsessions and compulsions, psychiatric disorders, personality dimensions, and other clinical characteristics separately in 151 men and 358 women with OCD who were examined during the OCD Collaborative Genetics Study. We found that, among men but not women, hoarding was associated with aggressive, sexual, and religious obsessions and checking compulsions. In men, hoarding was associated with generalized anxiety disorder and tics whereas, among women, hoarding was associated with social phobia, post-traumatic stress disorder, body dysmorphic disorder, nail biting, and skin picking. In women but not men, hoarding was associated with schizotypal and dependent personality disorder dimensions, and with low conscientiousness. These findings indicate that specific clinical correlates of hoarding in OCD are different in men and women and may reflect sex-specific differences in the course, expression, and/or etiology of hoarding behavior in OCD.

Escitalopram effects on insula and amygdala BOLD activation during emotional processing

RATIONALE

The amygdala and insular cortex are integral to the processing of emotionally salient stimuli. We have shown in healthy volunteers that an anxiolytic agent, lorazepam, dose-dependently attenuates activation of limbic structures.

OBJECTIVE

The current study investigated whether administration of a selective serotonin reuptake inhibitor (SSRI), escitalopram, alters the activation of limbic structures. We hypothesized that subchronic (21 days) SSRI treatment attenuates the activation of the amygdala and insula during processing of emotional faces.

MATERIALS AND METHODS

Thirteen healthy volunteers participated in a double-blind, placebo-controlled, crossover, randomized study. After 21 days of treatment with either escitalopram or placebo, participants underwent functional magnetic resonance imaging (fMRI) during which all subjects completed an emotion face assessment task, which has been shown to elicit amygdala and insula activation.

RESULTS

Subjects activated the bilateral insula and amygdala after treatment with both escitalopram and placebo. In subjects who were adherent to the protocol (as evidenced by sufficiently high urine concentrations of escitalopram), a reduction in amygdala activation was seen in the escitalopram condition compared to placebo.

CONCLUSION

The current investigation provides further evidence for the mechanism of action of SSRIs through the attenuation of activation in brain regions responsible for emotion processing and provides support for the use of blood oxygenation level-dependent fMRI with pharmacological probes to help identify the specific therapeutic effect of these agents in patients with anxiety and mood disorders.

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.

Paroxetine treatment of compulsive hoarding

OBJECTIVE

Compulsive hoarding, found in many patients with obsessive-compulsive disorder (OCD), has been associated with poor response to serotonin reuptake inhibitor (SRI) medications in some reports. However, no prior study has quantitatively measured response to standardized pharmacotherapy in compulsive hoarders. We sought to determine whether compulsive hoarders would respond as well as non-hoarding OCD patients to the SRI, paroxetine.

METHODS

Seventy-nine patients with OCD (32 patients with the compulsive hoarding syndrome and 47 patients without prominent hoarding symptoms) were treated openly with paroxetine (mean dose 41.6+/-12.8 mg/day; mean duration 80.4+/-23.5 days) according to a standardized protocol, from 3/1993 to 7/2005. All subjects were free of psychotropic medication for at least four weeks prior to study entry. No psychotherapy or psychotropic medications except paroxetine were allowed during the study period. Subjects were assessed before and after treatment with the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Hamilton Depression Rating Scale (HDRS), Hamilton Anxiety Scale (Ham-A), Global Assessment Scale (GAS), and Clinical Global Impression/Improvement (CGI) scale.

RESULTS

Both compulsive hoarders and non-hoarding OCD patients improved significantly with treatment (p<0.001), with nearly identical changes in Y-BOCS, HDRS, Ham-A, and GAS scores. There were no significant differences between groups in the proportions of patients who completed or responded to treatment. Hoarding symptoms improved as much as other OCD symptoms.

CONCLUSIONS

Compulsive hoarders responded as well to paroxetine treatment as non-hoarding OCD patients, suggesting that SRI medications are effective for compulsive hoarding. Controlled trials of SRI medications for compulsive hoarding are now warranted.

Taboo thoughts and doubt/checking: a refinement of the factor structure for obsessive-compulsive disorder symptoms

The purpose of this report was to improve upon earlier factor analyses of obsessive-compulsive disorder (OCD) symptom categories by minimizing the heterogeneity in the aggressive obsessions category. An exploratory factor analysis was conducted on data from 293 adults with primary OCD. The resulting five factors (Symmetry/Ordering, Hoarding, Doubt/Checking, Contamination/Cleaning, and Taboo Thoughts) are phenomenologically more homogeneous than prior category-based factors and are consistent with those derived in previous item-level analyses.

An open trial of cognitive-behavioral therapy for compulsive hoarding

The aim of the present study was to provide preliminary data on the efficacy of a new cognitive-behavioral treatment (CBT) for compulsive hoarding. Fourteen adults with compulsive hoarding (10 treatment completers) were seen in two specialty CBT clinics. Participants were included if they met research criteria for compulsive hoarding according to a semistructured interview, were age 18 or above, considered hoarding their main psychiatric problem, and were not receiving mental health treatment. Patients received 26 individual sessions of CBT, including frequent home visits, over a 7-12 month period between December 2003-February 2005. Primary outcome measures were the Saving Inventory-Revised (SI-R), Clutter Image Rating (CIR), and Clinician's Global Impression (CGI). Significant decreases from pre- to post-treatment were noted on the SI-R and CIR, but not the CGI-severity rating. CGI-Improvement ratings indicated that at mid-treatment, 40% (n=4) of treatment completers were rated "much improved" or "very much improved;" at post-treatment, 50% (n=5) received this rating. Adherence to homework assignments was strongly related to symptom improvement. CBT with specialized components to address problems with motivation, organizing, acquiring and removing clutter appears to be a promising intervention for compulsive hoarding, a condition traditionally thought to be resistant to treatment.

Exploratory analysis of obsessive compulsive symptom dimensions in children and adolescents: a prospective follow-up study

BACKGROUND

Recent statistical approaches based on factor analysis of obsessive compulsive (OC) symptoms in adult patients have identified dimensions that seem more effective in symptom-based taxonomies and appear to be more stable over time. Although a phenotypic continuum from childhood to adulthood has been hypothesized, no factor analytic studies have been performed in juvenile patients, and the stability of OC dimensions in children and adolescents has not been assessed.

METHODS

This study was designed to perform an exploratory factor analysis of OC symptoms in a sample of children and adolescents with OC disorder (OCD) and to investigate the course of factors over time (mean follow-up period: four years).

RESULTS

We report for the first time that four symptom dimensions, remarkably similar to those previously described in adults, underlined the heterogeneity of OC symptoms in children and adolescents. Moreover, after follow-up, the symptom dimensions identified remained essentially unmodified. The changes observed concerned the intensity of dimensions rather than shifts from one dimension to another.

CONCLUSION

These findings reinforce the hypothesis of a phenotypic continuum of OC symptoms from childhood to adulthood. They also strengthen the interest for investigating the clinical, neurobiological and genetic heterogeneity of OCD using a dimension-based approach.

Predictors of pharmacotherapy response in anxiety disorders

Although treatment with different compounds such as tricyclic antidepressants, selective serotonin reuptake inhibitors, high-potency benzodiazepines, and monoamine oxidase inhibitors has been proven effective in anxiety disorders, 20% to 40% of patients are nonresponders. Given the limited efficacy, the delayed onset of response (it takes several weeks before a clinical effect can be seen for most of these drugs), and the occurrence of side effects associated with pharmacotherapy, predicting response in anxiety disorders would be immensely valuable. This review surveys the literature over the past years on predictors of response to pharmacotherapy in obsessive-compulsive disorder, social anxiety disorder, panic disorder, and posttraumatic stress disorder. Prediction of treatment response may be founded on demographic and clinical variables, neurochemical and electrophysiologic parameters, imaging studies, and genetic markers.

Functional impairment in clinical samples of Norwegian and Swedish children and adolescents with obsessive-compulsive disorder

The aims of the present study were to examine OCD-related impairments in clinical cases of childhood OCD and to replicate and extend previous research on OCD-related impairments.

METHOD

Sixty-eight patients aged 8-17 years recruited from four child psychiatric outpatient clinics in Norway and Sweden with a confirmed DSM-IV diagnosis of OCD were included in the study. All patients and their parents were interviewed for diagnosis and comorbidity (KSADS),OCD symptoms and severity (CY-BOCS), and global impairment (CGAS). OCD-specific impairments were assessed by means of the Child OCD Impact Scale (COIS), a 58 item questionnaire with parallel parent and child versions.

RESULTS

Overall, the majority of patients suffered from substantial impairments. The impact of OCD symptoms was found to be most severe at home, but impairments were also prominent in situations related to school and social settings.

CONCLUSIONS

Our study supports findings of previous research suggesting multiple impacts of OCD symptoms on children's psychosocial functioning. We conclude that impairment issues should be further addressed in future research to establish a better empirical basis for the understanding of different aspects of OCD-related impairment.

Obsessional slowness in Down's syndrome

BACKGROUND

Obsessional slowness was originally described by S. Rachman in 1974. His patients had obsessive-compulsive disorder (OCD) and spent hours performing daily routines such as bathing, dressing and eating. Although some ritualistic behaviours were seen, slowness was the most prominent problem for these patients. Subsequently, a number of similar case reports emerged. In 1994, R. J. Pary described a small number of patients who had both obsessional slowness and Down's syndrome (DS). Apart from this, only one other report of slowness symptoms in people with developmental disabilities has been found in the literature, and this individual also had DS.

METHODS

In the present exploratory case series report, 11 individuals with DS and slowness are described based on a retrospective chart review. Descriptive data and four case vignettes are presented.

RESULTS

The 11 individuals with DS were described as spending hours engaged in usual daily routines. Several individuals had tics, hypothyroidism and periods of freezing. Although some ritualistic behaviours were described, slowness was seen to occur in the absence of these, and often without manifest anxiety.

DISCUSSION

Obsessional slowness may be a severe variant of OCD. Although it appears to occur infrequently, there may be an elevated rate in people with DS. The current report is severely limited in scope since the case descriptions were based on a retrospective review. However, because of the paucity of published information about this clinical phenomena, it was felt that the case series might serve to establish the need for further, more systematic, prospective evaluation of individuals with DS and clinically significant slowness.

Genomewide scan of hoarding in sib pairs in which both sibs have Gilles de la Tourette syndrome

A genome scan of the hoarding phenotype (a component of obsessive-compulsive disorder) was conducted on 77 sib pairs collected by the Tourette Syndrome Association International Consortium for Genetics (TSAICG). All sib pairs were concordant for a diagnosis of Gilles de la Tourette syndrome (GTS). However, the analyses reported here were conducted for hoarding as both a dichotomous trait and a quantitative trait. Not all sib pairs in the sample were concordant for hoarding. Standard linkage analyses were performed using GENEHUNTER and Haseman-Elston methods. In addition, novel analyses with a recursive-partitioning technique were employed. Significant allele sharing was observed for both the dichotomous and the quantitative hoarding phenotypes for markers at 4q34-35 (P=.0007), by use of GENEHUNTER, and at 5q35.2-35.3 (P=.000002) and 17q25 (P=.00002), by use of the revisited Haseman-Elston method. The 4q site is in proximity to D4S1625, which was identified by the TSAICG as a region linked to the GTS phenotype. The recursive-partitioning technique examined multiple markers simultaneously. Results suggest joint effects of specific loci on 5q and 4q, with an overall P value of.000003. Although P values were not adjusted for multiple comparison, nearly all were much smaller than the customary significance level of.0001 for genomewide scans.

The cognitive-affective neuroscience of obsessive-compulsive disorder

There is substantial evidence that obsessive-compulsive disorder (OCD) is mediated by specific cortico-striatal- thalamic-cortical (CTSC) circuits. Here we discuss very recent publications that address the following questions: How does damage to CSTC circuitry come about?; What are the neurochemical systems involved in mediating this circuitry?; and What are the implications of such damage for understanding the pathogenesis and management of OCD? A cognitive-affective neuroscience perspective is helpful in advancing our understanding of the role of these circuits in OCD and the dysfunctional procedural strategies that appear to characterize this disorder. Furthermore, this model is becoming integrated with a range of data including brain imaging, genetic, immunologic, and neurochemical findings.