Examining clinical correlates, treatment outcomes and mediators in young people with comorbid obsessive-compulsive disorder and autism spectrum disorder

Despite the high comorbidity, surprisingly little is known about the clinical features, treatment prognosis, and treatment mediators for youth with Obsessive-Compulsive Disorder (OCD) and Autism Spectrum Disorder (ASD). This study, the largest to date, compared 172 young people with OCD and ASD (OCD + ASD) to 447 without ASD (OCD) on clinical characteristics, finding those with OCD + ASD were more likely to endorse poorer insight into their OCD, have greater global functional impairment, greater levels of concurrent psychopathology, higher levels of family accommodation and to be on medication. Treatment outcomes following a course of Cognitive Behaviour Therapy with or without medication were explored for a subgroup; 100 young people with OCD + ASD and 223 with OCD. Whilst both groups benefitted from treatment, the OCD + ASD group had significantly poorer treatment outcomes. Greater global functional impairment and being on medication mediated the between-group difference in outcomes. Further research and treatment refinements are needed to improve outcomes for youth with OCD + ASD.

Protocol for the Process Evaluation of the Online Remote Behavioural Intervention for Tics (ORBIT) randomized controlled trial for children and young people

BACKGROUND

Process evaluations are an important component in the interpretation and understanding of outcomes in trials. The Online Remote Behavioural Intervention for Tics (ORBIT) study is a randomized controlled trial evaluating the effectiveness of an Internet-delivered behavioural intervention (called BIP TIC) compared to an Internet-delivered education programme aimed at children and young people with tics. A process evaluation will be undertaken alongside the main trial to determine precisely how the behavioural intervention works and ascertain whether, and if so, how, the intervention could be successfully implemented in standard clinical practice. This protocol paper describes the rationale, aims, and methodology of the ORBIT trial process evaluation.

METHODS

The process evaluation will have a mixed-methods design following the UK Medical Research Council 2015 guidelines, comprising both quantitative and qualitative data collection. This will include analysing data usage of participants in the intervention arm; purposively sampled, semi-structured interviews of parents and children, therapists and supervisors, and referring clinicians of the ORBIT trial, as well as analysis of qualitative comments put into the online therapy platform by participants at the end of treatment. Qualitative data will be analysed thematically. Quantitative and qualitative data will be integrated in a triangulation approach, to provide an understanding of how the intervention works, and what resources are needed for effective implementation, uptake and use in routine clinical care.

DISCUSSION

This process evaluation will explore the experiences of participants, therapists and supervisors and referring clinicians of a complex online intervention. By contextualising trial efficacy results, this will help understand how and if the intervention worked and what may be required to sustain the implementation of the treatment long term. The findings will also aid in our understanding of factors that can affect the success of complex interventions. This will enable future researchers developing online behavioural interventions for children and young people with mental health and neurological disorders to gain invaluable information from this process evaluation.

TRIAL REGISTRATION

International Standard Randomised Controlled Trials Number, ISRCTN70758207. Registered on 20 March 2018. ClinicalTrials.gov, NCT03483493. Registered on 30 March 2018.

Antidepressant prescription patterns and CNS polypharmacy with antidepressants among children, adolescents, and young adults: a population-based study in Sweden

This study examines trends in antidepressant drug dispensations among young people aged 0-24 years in Sweden during the period 2006-2013, as well as prescription patterns and central nervous system (CNS) polypharmacy with antidepressants. Using linkage of Swedish national registers, we identified all Swedish residents aged 0-24 years that collected at least one antidepressant prescription (here defined as antidepressant users) between 1 January 2006 and 31 December 2013 (n = 174,237), and categorized them as children (0-11 years), adolescents (12-17 years), and young adults (18-24 years). Prevalence of antidepressant dispensation rose from 1.4 to 2.1% between 2006 and 2013, with the greatest relative increase in adolescents [by 97.8% in males (from 0.6 to 1.3%) and by 86.3% in females (from 1.1 to 2.1%)]. Most individuals across age categories were prescribed selective serotonin reuptake inhibitors, received their prescriptions from psychiatric specialist care, and had treatment periods of over 12 months. Prevalence of CNS polypharmacy (dispensation of other CNS drug classes in addition to antidepressants) increased across age categories, with an overall increase in prevalence from 52.4% in 2006 to 62.1% in 2013. Children experienced the largest increase in polypharmacy of three or more psychotropic drug classes (4.4-10.1%). Anxiolytics, hypnotics, and sedatives comprised the most common additional CNS drug class among persons who were prescribed antidepressants. These findings show that the dispensation of antidepressants among the young is prevalent and growing in Sweden. The substantial degree of CNS polypharmacy in young patients receiving antidepressants requires careful monitoring and further research into potential benefits and harms.

A total-population multigenerational family clustering study of autoimmune diseases in obsessive-compulsive disorder and Tourette's/chronic tic disorders

The association between obsessive-compulsive disorder (OCD) and Tourette's/chronic tic disorders (TD/CTD) with autoimmune diseases (ADs) is uncertain. In this nationwide study, we sought to clarify the patterns of comorbidity and familial clustering of a broad range of ADs in individuals with OCD, individuals with TD/CTD and their biological relatives. From a birth cohort of 7 465 455 individuals born in Sweden between 1940 and 2007, we identified 30 082 OCD and 7279 TD/CTD cases in the National Patient Register and followed them up to 31 December 2013. The risk of 40 ADs was evaluated in individuals with OCD, individuals with TD/CTD and their first- (siblings, mothers, fathers), second- (half siblings) and third-degree (cousins) relatives, compared with population controls. Individuals with OCD and TD/CTD had increased comorbidity with any AD (43% and 36%, respectively) and many individual ADs. The risk of any AD and several individual ADs was consistently higher among first-degree relatives than among second- and third-degree relatives of OCD and TD/CTD probands. The risk of ADs was very similar in mothers, fathers and siblings of OCD probands, whereas it tended to be higher in mothers and fathers of TD/CTD probands (compared with siblings). The results suggest a familial link between ADs in general (that is, not limited to Streptococcus-related conditions) and both OCD and TD/CTD. Additional mother-specific factors, such as the placental transmission of antibodies, cannot be fully ruled out, particularly in TD/CTD.

Perinatal risk factors in Tourette's and chronic tic disorders: a total population sibling comparison study

Adverse perinatal events may increase the risk of Tourette's and chronic tic disorders (TD/CTD), but previous studies have been unable to control for unmeasured environmental and genetic confounding. We aimed to prospectively investigate potential perinatal risk factors for TD/CTD, taking unmeasured factors shared between full siblings into account. A population-based birth cohort, consisting of all singletons born in Sweden in 1973-2003, was followed until December 2013. A total of 3 026 861 individuals were identified, 5597 of which had a registered TD/CTD diagnosis. We then studied differentially exposed full siblings from 947 942 families; of these, 3563 families included siblings that were discordant for TD/CTD. Perinatal data were collected from the Medical Birth Register and TD/CTD diagnoses were collected from the National Patient Register, using a previously validated algorithm. In the fully adjusted models, impaired fetal growth, preterm birth, breech presentation and cesarean section were associated with a higher risk of TD/CTD, largely independent from shared family confounders and measured covariates. Maternal smoking during pregnancy was associated with risk of TD/CTD in a dose-response manner but the association was no longer statistically significant in the sibling comparison models or after the exclusion of comorbid attention-deficit/hyperactivity disorder. A dose-response relationship between the number of adverse perinatal events and increased risk for TD/CTD was also observed, with hazard ratios ranging from 1.41 (95% confidence interval (CI): 1.33-1.50) for one event to 2.42 (95% CI: 1.65-3.53) for five or more events. These results pave the way for future gene by environment interaction and epigenetic studies in TD/CTD.

Common and distinct patterns of grey-matter volume alteration in major depression and bipolar disorder: evidence from voxel-based meta-analysis

Finding robust brain substrates of mood disorders is an important target for research. The degree to which major depression (MDD) and bipolar disorder (BD) are associated with common and/or distinct patterns of volumetric changes is nevertheless unclear. Furthermore, the extant literature is heterogeneous with respect to the nature of these changes. We report a meta-analysis of voxel-based morphometry (VBM) studies in MDD and BD. We identified studies published up to January 2015 that compared grey matter in MDD (50 data sets including 4101 individuals) and BD (36 data sets including 2407 individuals) using whole-brain VBM. We used statistical maps from the studies included where available and reported peak coordinates otherwise. Group comparisons and conjunction analyses identified regions in which the disorders showed common and distinct patterns of volumetric alteration. Both disorders were associated with lower grey-matter volume relative to healthy individuals in a number of areas. Conjunction analysis showed smaller volumes in both disorders in clusters in the dorsomedial and ventromedial prefrontal cortex, including the anterior cingulate cortex and bilateral insula. Group comparisons indicated that findings of smaller grey-matter volumes relative to controls in the right dorsolateral prefrontal cortex and left hippocampus, along with cerebellar, temporal and parietal regions were more substantial in major depression. These results suggest that MDD and BD are characterised by both common and distinct patterns of grey-matter volume changes. This combination of differences and similarities has the potential to inform the development of diagnostic biomarkers for these conditions.

Comparison of neural substrates of temporal discounting between youth with autism spectrum disorder and with obsessive-compulsive disorder

BACKGROUND

Autism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD) share abnormalities in hot executive functions such as reward-based decision-making, as measured in the temporal discounting task (TD). No studies, however, have directly compared these disorders to investigate common/distinct neural profiles underlying such abnormalities. We wanted to test whether reward-based decision-making is a shared transdiagnostic feature of both disorders with similar neurofunctional substrates or whether it is a shared phenotype with disorder-differential neurofunctional underpinnings.

METHODS

Age and IQ-matched boys with ASD (N = 20), with OCD (N = 20) and 20 healthy controls, performed an individually-adjusted functional magnetic resonance imaging (fMRI) TD task. Brain activation and performance were compared between groups.

RESULTS

Boys with ASD showed greater choice-impulsivity than OCD and control boys. Whole-brain between-group comparison revealed shared reductions in ASD and OCD relative to control boys for delayed-immediate choices in right ventromedial/lateral orbitofrontal cortex extending into medial/inferior prefrontal cortex, and in cerebellum, posterior cingulate and precuneus. For immediate-delayed choices, patients relative to controls showed reduced activation in anterior cingulate/ventromedial prefrontal cortex reaching into left caudate, which, at a trend level, was more decreased in ASD than OCD patients, and in bilateral temporal and inferior parietal regions.

CONCLUSIONS

This first fMRI comparison between youth with ASD and with OCD, using a reward-based decision-making task, shows predominantly shared neurofunctional abnormalities during TD in key ventromedial, orbital- and inferior fronto-striatal, temporo-parietal and cerebellar regions of temporal foresight and reward processing, suggesting trans-diagnostic neurofunctional deficits.

Emotion regulation before and after transcranial magnetic stimulation in obsessive compulsive disorder

BACKGROUND

Impaired emotion regulation may underlie exaggerated emotional reactivity in patients with obsessive compulsive disorder (OCD), yet instructed emotion regulation has never been studied in the disorder.

METHOD

This study aimed to assess the neural correlates of emotion processing and regulation in 43 medication-free OCD patients and 38 matched healthy controls, and additionally test if these can be modulated by stimulatory (patients) and inhibitory (controls) repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex (dlPFC). Participants performed an emotion regulation task during functional magnetic resonance imaging before and after a single session of randomly assigned real or sham rTMS. Effect of group and rTMS were assessed on self-reported distress ratings and brain activity in frontal-limbic regions of interest.

RESULTS

Patients had higher distress ratings than controls during emotion provocation, but similar rates of distress reduction after voluntary emotion regulation. OCD patients compared with controls showed altered amygdala responsiveness during symptom provocation and diminished left dlPFC activity and frontal-amygdala connectivity during emotion regulation. Real v. sham dlPFC stimulation differentially modulated frontal-amygdala connectivity during emotion regulation in OCD patients.

CONCLUSIONS

We propose that the increased emotional reactivity in OCD may be due to a deficit in emotion regulation caused by a failure of cognitive control exerted by the dorsal frontal cortex. Modulatory rTMS over the left dlPFC may influence automatic emotion regulation capabilities by influencing frontal-limbic connectivity.

Population-based, multi-generational family clustering study of social anxiety disorder and avoidant personality disorder

BACKGROUND

We aimed to provide unbiased estimates of familial risk and heritability of social anxiety disorder (SAD) and avoidant personality disorder (AVPD).

METHOD

We identified 18 399 individuals diagnosed with SAD and 2673 with AVPD in the Swedish National Patient Register between 1997 and 2009. Risks (odds ratios; OR) for SAD in all biological and non-biological relatives of probands, compared to relatives of unaffected individuals were calculated. We also estimated the risks for AVPD in relatives of probands with SAD.

RESULTS

The risk for SAD among relatives of SAD probands increased proportionally to the degree of genetic relatedness. The risks for first-degree relatives [OR 4.74, 95% confidence interval (CI) 4.28-5.25] were significantly higher than for second-degree and third-degree relatives. Second-degree relatives (OR 2.30, 95% CI 2.01-2.63) had significantly higher risk than third-degree relatives (OR 1.72, 95% CI 1.52-1.94). Relatives at similar genetic distances had similar risks for SAD, despite different degrees of shared environment. Heritability was estimated to be approximately 56%. There were no significant sex differences in the familial patterns. The risk of AVPD in relatives of SAD probands was significantly elevated, even after excluding individuals with both diagnoses (first-degree OR 3.54, second-degree OR 2.20, third-degree OR 1.62). Non-biological relatives (spouses/partners) also had elevated risks for both SAD (OR 4.01) and AVPD (OR 3.85).

CONCLUSIONS

SAD clusters in families primarily due to genetic factors. SAD and AVPD are aetiologically related and may represent different expressions of the same vulnerability. The strong marital concordance observed in SAD/AVPD may indicate assortative mating but the exact mechanisms and implications require further investigation.

Predicting response to cognitive behavioral therapy in contamination-based obsessive-compulsive disorder from functional magnetic resonance imaging

BACKGROUND

Although cognitive behavioral therapy (CBT) is an effective treatment for obsessive-compulsive disorder (OCD), few reliable predictors of treatment outcome have been identified. The present study examined the neural correlates of symptom improvement with CBT among OCD patients with predominantly contamination obsessions and washing compulsions, the most common OCD symptom dimension.

METHOD

Participants consisted of 12 OCD patients who underwent symptom provocation with contamination-related images during functional magnetic resonance imaging (fMRI) scanning prior to 12 weeks of CBT.

RESULTS

Patterns of brain activity during symptom provocation were correlated with a decrease on the Yale-Brown Obsessive Compulsive Scale (YBOCS) after treatment, even when controlling for baseline scores on the YBOCS and the Beck Depression Inventory (BDI) and improvement on the BDI during treatment. Specifically, activation in brain regions involved in emotional processing, such as the anterior temporal pole and amygdala, was most strongly associated with better treatment response. By contrast, activity in areas involved in emotion regulation, such as the dorsolateral prefrontal cortex, correlated negatively with treatment response mainly in the later stages within each block of exposure during symptom provocation.

CONCLUSIONS

Successful recruitment of limbic regions during exposure to threat cues in patients with contamination-based OCD may facilitate a better response to CBT, whereas excessive activation of dorsolateral prefrontal regions involved in cognitive control may hinder response to treatment. The theoretical implications of the findings and their potential relevance to personalized care approaches are discussed.

Aetiological overlap between obsessive-compulsive and depressive symptoms: a longitudinal twin study in adolescents and adults

BACKGROUND

Depression is commonly co-morbid with obsessive-compulsive disorder (OCD). However, it is unknown whether depression is a functional consequence of OCD or whether these disorders share a common genetic aetiology. This longitudinal twin study compared these two hypotheses.

METHOD

Data were drawn from a longitudinal sample of adolescent twins and siblings (n = 2651; Genesis 12-19 study) and from a cross-sectional sample of adult twins (n = 4920). The longitudinal phenotypic associations between OCD symptoms (OCS) and depressive symptoms were examined using a cross-lag model. Multivariate twin analyses were performed to explore the genetic and environmental contributions to the cross-sectional and longitudinal relationship between OCS and depressive symptoms.

RESULTS

In the longitudinal phenotypic analyses, OCS at time 1 (wave 2 of the Genesis 12-19 study) predicted depressive symptoms at time 2 (wave 3 of the Genesis 12-19 study) to a similar extent to which depressive symptoms at time 1 predicted OCS at time 2. Cross-sectional twin analyses in both samples indicated that common genetic factors explained 52-65% of the phenotypic correlation between OCS and depressive symptoms. The proportion of the phenotypic correlation due to common non-shared environmental factors was considerably smaller (35%). In the adolescent sample, the longitudinal association between OCS at time 1 and subsequent depressive symptoms was accounted for by the genetic association between OCS and depressive symptoms at time 1. There was no significant environmental association between OCS and later depressive symptoms.

CONCLUSIONS

The present findings show that OCS and depressive symptoms co-occur primarily due to shared genetic factors and suggest that genetic, rather than environmental, effects account for the longitudinal relationship between OCS and depressive symptoms.

Neurological soft signs in obsessive-compulsive disorder: two empirical studies and meta-analysis

BACKGROUND

Neurological soft signs (NSS) have been inconsistently reported in obsessive-compulsive disorder (OCD) but may make an impact on treatment response. Method The current study examined the presence of NSS in two independent European samples of OCD patients (combined 85 patients and 88 matched healthy controls) using a standardized instrument and conducted a meta-analysis of all published studies identified in the literature with the aim to provide a more definitive answer to the question of whether OCD patients are characterized by increased NSS.

RESULTS

Both empirical studies found elevated NSS scores in patients compared with matched controls. The results of the meta-analysis, which included 15 studies (combined 498 patients and 520 controls) showed large effect sizes (Hedges' g=1.27, 95% confidence interval 0.80-1.75), indicating that OCD patients have significantly higher rates of NSS than matched controls on both sides of the body and in multiple domains (motor coordination, sensory integration and primitive reflexes). The results were robust and remained largely unchanged in our reliability analyses, which controlled for possible outliers. Meta-regression was employed to examine the role of potential variables of interest including sociodemographic variables, symptom severity, medication effects and the use of different instruments, but none of these variables was clearly associated with NSS.

CONCLUSIONS

As a group, OCD patients are characterized by increased rates of NSS, compared with healthy controls. However, their origins and potential clinical importance remain to be clarified. Future directions for research are discussed.

The London field trial for hoarding disorder

BACKGROUND

A new diagnostic category, hoarding disorder (HD), has been proposed for inclusion in DSM-5. This study field-tested the validity, reliability and perceived acceptability of the proposed diagnostic criteria for HD. Method Fifty unselected individuals with prominent hoarding behavior and 20 unselected, self-defined 'collectors' participated in thorough psychiatric assessments, involving home visits whenever possible. A semi-structured interview based on the proposed diagnostic criteria for HD was administered and scored by two independent raters. 'True' diagnoses were made by consensus according to the best-estimate diagnosis procedure. The percentage of true positive HD cases (sensitivity) and true negative HD cases (specificity) was calculated, along with inter-rater reliability for the diagnosis and each criterion. Participants were asked about their perceptions of the acceptability, utility and stigma associated with the new diagnosis.

RESULTS

Twenty-nine (58%) of the hoarding individuals and none of the collectors fulfilled diagnostic criteria for HD. The sensitivity, specificity and inter-rater reliability of the diagnosis, and of each individual criterion and the specifiers, were excellent. Most participants with HD (96%) felt that creating a new disorder would be very or somewhat acceptable, useful (96%) and not too stigmatizing (59%).

CONCLUSIONS

The proposed HD criteria are valid, reliable and perceived as acceptable and useful by the sufferers. Crucially, they seem to be sufficiently conservative and unlikely to overpathologize normative behavior. Minor changes in the wording of the criteria are suggested.

A general approach for combining voxel-based meta-analyses conducted in different neuroimaging modalities

Meta-analyses are useful to summarize the exponential amount of inconsistent and conflicting neuroimaging data. However, they are usually separately conducted for each different neuroimaging modality, preventing the multimodal integration of different imaging findings in a given neuropsychiatric disorder. Here, we describe an innovative method to meta-analytically combine the results of different imaging modalities, such as structural and functional paradigms. The method accounts for the presence of noise in the estimation of the p-values, and can be easily applied to any meta-analytical software. We hope that with this advanced imaging tool, researchers will be able to provide more complete multimodal pictures of the brain regions affected in different neuropsychiatric disorders.

A twin study of body dysmorphic concerns

BACKGROUND

Dysmorphic concern refers to an excessive preoccupation with a perceived or slight defect in physical appearance. It lies on a continuum of severity from no or minimal concerns to severe concerns over one's appearance. The present study examined the heritability of dysmorphic concerns in a large sample of twins.

METHOD

Twins from the St Thomas UK twin registry completed a valid and reliable self-report measure of dysmorphic concerns, which also includes questions about perceived body odour and malfunction. Twin modelling methods (female twins only, n=3544) were employed to decompose the variance in the liability to dysmorphic concerns into additive genetic, shared and non-shared environmental factors.

RESULTS

Model-fitting analyses showed that genetic factors accounted for approximately 44% [95% confidence intervals (CI) 36-50%] of the variance in dysmorphic concerns, with non-shared environmental factors and measurement error accounting for the remaining variance (56%; 95% CI 50-63%). Shared environmental factors were negligible. The results remained unchanged when excluding individuals reporting an objective medical condition/injury accounting for their concern in physical appearance.

CONCLUSIONS

Over-concern with a perceived or slight defect in physical appearance is a heritable trait, with non-shared environmental factors also playing an important role in its causation. The results are relevant for various psychiatric disorders characterized by excessive concerns in body appearance, odour or function, including but not limited to body dysmorphic disorder.

Testing the validity and acceptability of the diagnostic criteria for Hoarding Disorder: a DSM-5 survey

BACKGROUND

The DSM-5 Obsessive-Compulsive Spectrum Sub-Workgroup is recommending the creation of a new diagnostic category named Hoarding Disorder (HD). The validity and acceptability of the proposed diagnostic criteria have yet to be formally tested.

METHOD

Obsessive-compulsive disorder/hoarding experts and random members of the American Psychiatric Association (APA) were shown eight brief clinical vignettes (four cases meeting criteria for HD, three with hoarding behaviour secondary to other mental disorders, and one with subclinical hoarding behaviour) and asked to decide the most appropriate diagnosis in each case. Participants were also asked about the perceived acceptability of the criteria and whether they supported the inclusion of HD in the main manual.

RESULTS

Altogether, 211 experts and 48 APA members completed the survey (30% and 10% response rates, respectively). The sensitivity and specificity of the HD diagnosis and the individual criteria were high (80-90%) across various types of professionals, irrespective of their experience with hoarding cases. About 90% of participants in both samples thought the criteria would be very/somewhat acceptable for professionals and sufferers. Most experts (70%) supported the inclusion of HD in the main manual, whereas only 50% of the APA members did.

CONCLUSIONS

The proposed criteria for HD have high sensitivity and specificity. The criteria are also deemed acceptable for professionals and sufferers alike. Training of professionals and the development and validation of semi-structured diagnostic instruments should improve diagnostic accuracy even further. A field trial is now needed to confirm these encouraging findings with real patients in real clinical settings.

Risk factors prospectively associated with adult obsessive-compulsive symptom dimensions and obsessive-compulsive disorder

BACKGROUND

Very few longitudinal studies have evaluated prospective neurodevelopmental and psychosocial risk factors for obsessive-compulsive disorder (OCD). Furthermore, despite the heterogeneous nature of OCD, no research has examined risk factors for its primary symptom dimensions, such as contamination/washing.

METHOD

Potential risk factors for symptoms or diagnosis of OCD in adulthood and for specific adult obsessive-compulsive (OC) symptom dimensions were examined in the Dunedin Study birth cohort. The presence of obsessions and compulsions and psychological disorders was assessed using the Diagnostic Interview Schedule (DIS) at ages 26 and 32 years. Individuals with a diagnosis of OCD at either age (n=36) were compared to both a healthy control group (n=613) and an anxious control group (n=310) to determine whether associations between a risk factor and an OCD diagnosis were specific.

RESULTS

Childhood neurodevelopmental, behavioral, personality and environmental risk factors were associated with a diagnosis of OCD and with OC symptoms at ages 26 and 32. Social isolation, retrospectively reported physical abuse and negative emotionality were specific predictors of an adult OCD diagnosis. Of note, most risk factors were associated with OC symptoms in adulthood and several risk factors predicted specific OCD dimensions. Perinatal insults were linked to increased risk for symmetry/ordering and shameful thoughts dimensions, whereas poor childhood motor skills predicted the harm/checking dimension. Difficult temperament, internalizing symptoms and conduct problems in childhood also predicted specific symptom dimensions and lower IQ non-specifically predicted increased risk for most dimensions.

CONCLUSIONS

The current findings underscore the need for a dimensional approach in evaluating childhood risk factors for obsessions and compulsions.

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.

Common limbic and frontal-striatal disturbances in patients with obsessive compulsive disorder, panic disorder and hypochondriasis

BACKGROUND

Direct comparisons of brain function between obsessive compulsive disorder (OCD) and other anxiety or OCD spectrum disorders are rare. This study aimed to investigate the specificity of altered frontal-striatal and limbic activations during planning in OCD, a prototypical anxiety disorder (panic disorder) and a putative OCD spectrum disorder (hypochondriasis).

METHOD

The Tower of London task, a 'frontal-striatal' task, was used during functional magnetic resonance imaging measurements in 50 unmedicated patients, diagnosed with OCD (n=22), panic disorder (n=14) or hypochondriasis (n=14), and in 22 healthy subjects. Blood oxygen level-dependent (BOLD) signal changes were calculated for contrasts of interest (planning versus baseline and task load effects). Moreover, correlations between BOLD responses and both task performance and state anxiety were analysed.

RESULTS

Overall, patients showed a decreased recruitment of the precuneus, caudate nucleus, globus pallidus and thalamus, compared with healthy controls. There were no statistically significant differences in brain activation between the three patient groups. State anxiety was negatively correlated with dorsal frontal-striatal activation. Task performance was positively correlated with dorsal frontal-striatal recruitment and negatively correlated with limbic and ventral frontal-striatal recruitment. Multiple regression models showed that adequate task performance was best explained by independent contributions from dorsolateral prefrontal cortex (positive correlation) and amygdala (negative correlation), even after controlling for state anxiety.

CONCLUSIONS

Patients with OCD, panic disorder and hypochondriasis share similar alterations in frontal-striatal brain regions during a planning task, presumably partly related to increased limbic activation.

Voxel-based meta-analysis of regional white-matter volume differences in autism spectrum disorder versus healthy controls

BACKGROUND

We conducted a meta-analysis of voxel-based morphometry (VBM) studies in autism spectrum disorder (ASD) to clarify the changes in regional white-matter volume underpinning this condition, and generated an online database to facilitate replication and further analyses by other researchers.

METHOD

PubMed, ScienceDirect, Web of Knowledge and Scopus databases were searched between 2002 (the date of the first white-matter VBM study in ASD) and 2010. Manual searches were also conducted. Authors were contacted to obtain additional data. Coordinates were extracted from clusters of significant white-matter difference between patients and controls. A new template for white matter was created for the signed differential mapping (SDM) meta-analytic method. A diffusion tensor imaging (DTI)-derived atlas was used to optimally localize the changes in white-matter volume.

RESULTS

Thirteen datasets comprising 246 patients with ASD and 237 healthy controls met inclusion criteria. No between-group differences were found in global white-matter volumes. ASD patients showed increases of white-matter volume in the right arcuate fasciculus and also in the left inferior fronto-occipital and uncinate fasciculi. These findings remained unchanged in quartile and jackknife sensitivity analyses and also in subgroup analyses (pediatric versus adult samples).

CONCLUSIONS

Patients with ASD display increases of white-matter volume in tracts known to be important for language and social cognition. Whether the results apply to individuals with lower IQ or younger age and whether there are meaningful neurobiological differences between the subtypes of ASD remain to be investigated.

A new meta-analytic method for neuroimaging studies that combines reported peak coordinates and statistical parametric maps

Meta-analyses are essential to summarize the results of the growing number of neuroimaging studies in psychiatry, neurology and allied disciplines. Image-based meta-analyses use full image information (i.e. the statistical parametric maps) and well-established statistics, but images are rarely available making them highly unfeasible. Peak-probability meta-analyses such as activation likelihood estimation (ALE) or multilevel kernel density analysis (MKDA) are more feasible as they only need reported peak coordinates. Signed-differences methods, such as signed differential mapping (SDM) build upon the positive features of existing peak-probability methods and enable meta-analyses of studies comparing patients with controls. In this paper we present a new version of SDM, named Effect Size SDM (ES-SDM), which enables the combination of statistical parametric maps and peak coordinates and uses well-established statistics. We validated the new method by comparing the results of an ES-SDM meta-analysis of studies on the brain response to fearful faces with the results of a pooled analysis of the original individual data. The results showed that ES-SDM is a valid and reliable coordinate-based method, whose performance might be additionally increased by including statistical parametric maps. We anticipate that ES-SDM will be a helpful tool for researchers in the fields of psychiatry, neurology and allied disciplines.

Independent validation of the dimensional Yale-Brown obsessive-compulsive scale (DY-BOCS)

INTRODUCTION

Obsessive-compulsive disorder (OCD) is a clinically heterogeneous condition characterized by a few consistent, temporally stable symptom dimensions. The dimensional Yale-Brown obsessive-compulsive scale (DY-BOCS) is a recently developed instrument that allows patient and clinician ratings of dimension-specific symptom severity, as well as estimates of global symptom severity in patients with OCD.

METHODS

We examined the psychometric properties of the DY-BOCS in a sample of 128 European adult patients with OCD.

RESULTS

The results of the psychometric analyses were overall excellent. The internal consistency across the domains of time, distress and interference for each dimension was high. The subscales of the DY-BOCS were largely independent from one another. The convergent and discriminant validity of the DY-BOCS subscales were adequate. The Global Severity and Interference scales were largely intercorrelated, suggesting that they may be redundant. The level of agreement between self-report and expert ratings was adequate although somewhat lower than in the original validation study.

CONCLUSION

The results of the present study confirm the excellent psychometric properties of the DY-BOCS reported in the original validation study.

Long-term outcomes of obsessive-compulsive disorder: follow-up of 142 children and adolescents

BACKGROUND

Obsessive-compulsive disorder (OCD) often starts in childhood and adolescence and can be a chronic disorder with high persistence rates. There are few prospective long-term follow-up studies.

AIMS

To follow up young people with OCD to clarify persistence rates and relevant predictors, presence of other psychiatric disorders, functional impairment, service utilisation and perceived treatment needs.

METHOD

All young people with OCD assessed over 9 years at the National and Specialist Paediatric OCD clinic, Maudsley Hospital, London, were included. Sixty-one per cent (142 of 222) of all contactable young people and parents completed computerised diagnostic interviews and questionnaires.

RESULTS

We found a persistence rate of OCD of 41%; 40% of participants had a psychiatric diagnosis other than OCD at follow-up. The main predictor for persistent OCD was duration of illness at assessment. High levels of baseline psychopathology predicted other psychiatric disorders at follow-up. Functional impairment and quality of life were mildly to moderately affected. Approximately 50% of participants were still receiving treatment and about 50% felt a need for further treatment.

CONCLUSIONS

This study confirms that paediatric OCD can be a chronic condition that persists into adulthood. Early recognition and treatment might prevent chronicity. Important challenges for services are ensuring adequate treatment and a smooth transition from child to adult services.

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.

The functional neuroanatomy of blood-injection-injury phobia: a comparison with spider phobics and healthy controls

BACKGROUND

Most neuroimaging studies of specific phobia have investigated the animal subtype. The blood-injection-injury (BII) subtype is characterized by a unique biphasic psychophysiological response, which could suggest a distinct neural substrate, but direct comparisons between phobia types are lacking.

METHOD

This study compared the neural responses during the presentation of phobia-specific stimuli in 12 BII phobics, 14 spider (SP) phobics and 14 healthy controls using functional magnetic resonance imaging (fMRI).

RESULTS

Subjective ratings showed that the experimental paradigm produced the desired symptom-specific effects. As in many previous studies, when viewing spider-related stimuli, SP phobics showed increased activation in dorsal anterior cingulate and anterior insula, compared to BII phobics and healthy controls. However, when viewing images of blood-injection-injuries, participants with BII phobia mainly showed increased activation in the thalamus and visual/attention areas (occipito-temporo-parietal cortex), compared with the other two groups. The degree of provoked anxiety and disgust by phobia-relevant images was strongly associated with activation in several common regions across the two phobia groups (thalamus, cerebellum, occipito-temporal regions) but only correlated with activation in the dorsal anterior cingulate gyrus and the anterior insula in the SP phobics.

CONCLUSIONS

These results suggest partially distinct neurobiological substrates of animal and BII phobias and support their current classification as two distinct subtypes in the DSM-IV-TR. Further research is needed to better understand the precise neurobiological mechanisms in BII phobia and particularly the fainting response.

To discard or not to discard: the neural basis of hoarding symptoms in obsessive-compulsive disorder

Preliminary neuroimaging studies suggest that patients with the 'compulsive hoarding syndrome' may be a neurobiologically distinct variant of obsessive-compulsive disorder (OCD) but further research is needed. A total of 29 OCD patients (13 with and 16 without prominent hoarding symptoms) and 21 healthy controls of both sexes participated in two functional magnetic resonance imaging experiments consisting of the provocation of hoarding-related and symptom-unrelated (aversive control) anxiety. In response to the hoarding-related (but not symptom-unrelated) anxiety provocation, OCD patients with prominent hoarding symptoms showed greater activation in bilateral anterior ventromedial prefrontal cortex (VMPFC) than patients without hoarding symptoms and healthy controls. In the entire patient group (n=29), provoked anxiety was positively correlated with activation in a frontolimbic network that included the anterior VMPFC, medial temporal structures, thalamus and sensorimotor cortex. Negative correlations were observed in the left dorsal anterior cingulate gyrus, bilateral temporal cortex, bilateral dorsolateral/medial prefrontal regions, basal ganglia and parieto-occipital regions. These results were independent from the effects of age, sex, level of education, state anxiety, depression, comorbidity and use of medication. The findings are consistent with the animal and lesion literature and several landmark clinical features of compulsive hoarding, particularly decision-making difficulties. Whether the results are generalizable to hoarders who do not meet criteria for OCD remains to be investigated.

The neural correlates of fatigue: an exploratory imaginal fatigue provocation study in chronic fatigue syndrome

BACKGROUND

Fatigue is the central symptom in chronic fatigue syndrome (CFS) and yet very little is known about its neural correlates. The aim of this study was to explore the functional brain response, using functional magnetic resonance imaging (fMRI), to the imaginal experience of fatigue in CFS patients and controls.

METHOD

We compared the blood oxygen level dependent (BOLD) responses of 12 CFS patients and 11 healthy controls to a novel fatigue provocation procedure designed to mimic real-life situations. A non-fatiguing anxiety-provoking condition was also included to control for the non-specific effects of negative affect.

RESULTS

During the provocation of fatigue, CFS patients reported feelings of both fatigue and anxiety and, compared to controls, they showed increased activation in the occipito-parietal cortex, posterior cingulate gyrus and parahippocampal gyrus, and decreased activation in dorsolateral and dorsomedial prefrontal cortices. The reverse pattern of findings was observed during the anxiety-provoking scenarios.

CONCLUSIONS

The results may suggest that, in CFS patients, the provocation of fatigue is associated with exaggerated emotional responses that patients may have difficulty suppressing. These findings are discussed in relation to the cognitive-behavioural model of CFS.

Saving clinicians' time by delegating routine aspects of therapy to a computer: a randomized controlled trial in phobia/panic disorder

BACKGROUND

The demand for time-consuming psychotherapy of phobia/panic exceeds the supply of trained therapists. Delegating routine therapy aspects to a computer might ease this problem.

METHOD

Ninety-three out-patients with phobia or panic disorder were randomized in a 2: 2 : 1 ratio to have self-exposure therapy guided either mainly by a stand-alone computer system (FearFighter) or entirely face-to-face by a clinician, or to have mainly computer-guided self-relaxation as a placebo. Both computer groups (FearFighter and relaxation) had brief back-up advice from a clinician. Primary outcome measures were self- and blind-assessor ratings of Main Problem and Goals, and Global Phobia.

RESULTS

Drop-outs occurred significantly more often in the two self-exposure groups (43% if mainly computer-guided, 24% if entirely clinician-guided) than with self-relaxation (6%); the difference between the two self-exposure groups was not significant. Even with all drop-outs included, the mainly computer-guided exposure group and the relaxation group had 73% less clinician time per patient than did the entirely clinician-guided exposure group. The two self-exposure groups had comparable improvement and satisfaction at post-treatment and at 1-month follow-up, while relaxation was ineffective. Mean improvement on the primary outcome measures (self- and assessor-rated) was 46% computer, 49% clinician, 9% relaxation at post-treatment (week 10) and 58% computer, 53% clinician and -4% relaxation at 1-month follow-up (week 14). Mean effect sizes on the primary outcome measures were 2.9 computer, 3.5 clinician and 0.5 relaxation at post-treatment; and 3.7 computer, 3.5 clinician and 0.5 relaxation at 1-month follow-up. The assessor did not rate patients at follow-up.

CONCLUSIONS

Despite its (non-significantly) higher dropout rate, self-exposure therapy for panic/ phobia cut clinician time per patient by 73% without losing efficacy when guided mainly by a computer rather than entirely by a clinician. The finding needs confirmation at a follow-up that is longer and includes a blind assessor. Self-relaxation had the highest rate of completers but was ineffective.

Neuroactivación con torre de Hanoi en pacientes con trastorno obsesivo-compulsivo y voluntarios sanos

The aim of the study was to evaluate changes in regional cerebral blood flow (rCBF) in obsessive-compulsive disorder (OCD) patients and healthy controls during performance of Tower of Hanoi (TOH) test (cognitive task).

MATERIAL AND METHODS

We compared TOH test performance in 30 OCD patients and 30 individually matched healthy volunteers. Intelligence and anxiety measurements were taken into account for all participants. Within the patient group, factors such as duration and severity of symptoms and low mood were considered. rCBF was estimated through the uptake of 99mTc-hexamethylpropylamine-oxime (HMPAO) on single photon emission computerised tomography (SPECT). Regional values were quantified as ratios of cortical blood flow.

RESULTS

OCD patients and volunteers differed significantly in terms of subjective anxiety during procedures. TOH test performance was significantly impaired in OCD patients when compared with matched controls. 2-tailed t tests for repeated measures suggested that there were overall significant differences (p = 0.039) between both groups (OCD patients and controls) confined to left caudate activation. There was increased activity after activation in control subjects, but not in OCD patients. No differences in other regions were observed.

CONCLUSIONS

These results suggest a modification of the activating systems of basal ganglia functions in OCD compared with normal subjects.

Long-term follow-up and predictors of clinical outcome in obsessive-compulsive patients treated with serotonin reuptake inhibitors and behavioral therapy

BACKGROUND

The objective of this study was to examine the long-term course of obsessive-compulsive disorder (OCD) in patients treated with serotonin reuptake inhibitors (SRIs) and behavioral therapy and to identify predictors of clinical outcome.

METHOD

Sixty outpatients meeting DSM-II-R or DSM-IV criteria for OCD were followed up for 1 to 5 years (mean = 2.5 years). All of them received prolonged pharmacologic therapy with an SRI.

RESULTS

Thirty-seven patients (61.7%) completed an adequate behavioral treatment. At long-term assessment, 22 patients (36.7%) exhibited a global Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score greater than 16 or a final reduction in Y-BOCS global score of less than 35% and were considered nonresponders. Patients who completed behavioral therapy showed a significant decrease in Y-BOCS compulsions subscale score (p = .01), whereas no significant differences in either Y-BOCS global or obsessions subscale scores between those who did and those who did not undergo behavioral therapy were detected. Obsessions of sexual/religious content were the unique factor related to a poorer long-term outcome.

CONCLUSION

A substantial number of OCD patients showed persistent disabling symptoms at the long-term follow-up in spite of combined pharmacologic and behavioral treatment. Major benefits from behavioral therapy appeared to be the improvement of ritualistic behaviors. Sexual/religious obsessions predicted poorer long-term outcome, whereas short-term response to SRI treatment failed to achieve predictive value in the long-term course of OCD.

Two-year follow-up after a randomised controlled trial of self- and clinician-accompanied exposure for phobia/panic disorders

BACKGROUND

Long-term follow-up has rarely been reported after self-exposure therapy for phobias.

AIMS

Completion of such a follow-up.

METHOD

Two-year follow-up was achieved in 68 (85%) of 80 patients with phobias who had completed a previous 14-week randomised controlled trial comparing therapist-accompanied self-exposure, self-exposure or self-relaxation. Measures were self-reported ratings of symptoms, satisfaction and use of other treatment.

RESULTS

Improvement at week 14 was maintained 2 years later. Clinician-accompanied exposure and self-exposure did not differ on any measure. Compliance with self-exposure homework during weeks 0-8 predicted more improvement 2 years later. Patients who failed to improve with relaxation by week 14 improved after subsequent crossover to exposure. A need for more treatment for their phobias was still felt by 33 patients (49%).

CONCLUSIONS

Patients with phobias maintained their improvement to 2-year follow-up after the end of self-exposure therapy.

Reliability and validity of a scoring system for measuring organizational approach in the Complex Figure Test

The Rey-Osterrieth Complex Figure Test (RCFT) is a widely-used measure of visuospatial construction and nonverbal memory. One of the critical aspects of this test is that organizing the figure into meaningful perceptual units during copy enhances its subsequent free recall from memory. This study examined the psychometric properties of a new system for quantifying the organizational approach to the RCFT figure and compared it to another compatible scoring system. We investigated interrater reliability of both systems and explored the influences of copy organization and copy accuracy on immediate recall. Seventy-one participants meeting DSM-IV criteria for obsessive-compulsive disorder and 55 healthy control participants completed the copy and immediate free recall condition of the RCFT. Interrater reliability was evaluated by Kappa coefficients and Pearson correlations. The effects of copy organization and copy accuracy on immediate recall were evaluated using multiple regression analyses. Results indicated that the organizational approach could be assessed with high reliability using both scoring systems. Organization during copy was a strong predictor for subsequent free recall from memory using both approaches. Multiple regression analysis indicated that all organizational elements were not equally predictive of memory performance. This new system represents a very simple and reliable approach to scoring organization on the RCFT, since it requires the identification of only 5 figure components. These characteristics should contribute to its clinical utility.

Relation of factor-analyzed symptom dimensions of obsessive-compulsive disorder to personality disorders

OBJECTIVE

To assess the relation between symptom dimensions of obsessive-compulsive disorder (OCD) and comorbid personality disorders (PDs).

METHOD

The scores of 75 OCD outpatients on five previously identified symptom dimensions were entered into multiple regression models as predictors of: 1) the presence of any type of PD; 2) the number of PDs; 3) the presence of any cluster A, B or C PD; and 4) the presence of each individual PD.

RESULTS

Twenty-eight patients (37.3%) met criteria for one or more PDs. High scores on the 'Hoarding' dimension were strongly related to the presence of any Axis II diagnosis, and to the number of PDs. Cluster C PDs (especially obsessive-compulsive and avoidant) had the highest partial correlations with 'Hoarding'. These results were independent of OCD symptom severity.

CONCLUSION

Previous conflicting findings about the prevalence of certain PDs in OCD might be due in part to differences in the constitution of the particular patient groups studied.

Adult gender identity disorder can remit

A 4-year remission in a case of gender identity disorder (GID in DSM-IV, previously termed transsexualism) plus obsessive-compulsive disorder (OCD) prompted a search for further similar cases. Reports were reviewed for apparent remissions in adult GID. GID and paraphilias may wax and wane. This fluctuation can be in tandem with that of comorbid psychopathology or in response to sexual and other life events. Remission has been documented at up to 10 years. If evaluated over many years, GIDs and paraphilias can be less fixed than is often thought. The frequency of permanent remission may be underestimated, as such subjects may not consult clinicians. Implications for the clinician are that such subjects require a long trial period of cross-gender living prior to any surgical interventions.

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

OBJECTIVE

No consistent predictors of outcome have been identified for the pharmaco-therapy of obsessive-compulsive disorder (OCD). Recent factor analytic studies have identified meaningful symptom dimensions that may be related to response to serotonin reuptake inhibitors and other treatments.

METHOD

A total of 354 outpatients with primary OCD were administered the Yale-Brown Obsessive Compulsive Scale Symptom Checklist, and its 13 main symptom categories were factor analyzed by using principal components analysis. The identified symptom dimensions were then entered into multiple regression models as outcome predictors of response to serotonin reuptake inhibitors and placebo response in a group of 150 nondepressed subjects who completed six double-blind, placebo-controlled trials with a serotonin reuptake inhibitor (clomipramine, fluvoxamine, fluoxetine, sertraline, and paroxetine). Eighty-four patients received a serotonin reuptake inhibitor and 66, placebo.

RESULTS

The principal components analysis identified five factors that explained 65.5% of variance in outcome: symmetry/ordering, hoarding, contamination/cleaning, aggressive/checking, and sexual/religious obsessions. Serotonin reuptake inhibitors were significantly superior to placebo on all outcome measures. Initial severity of OCD was related to greater posttreatment severity of OCD. Higher scores on the hoarding dimension predicted poorer outcome following treatment with serotonin reuptake inhibitors, after control for baseline severity. No predictors of placebo response were identified. Exclusion of clomipramine did not modify the overall results, suggesting a cross-serotonin reuptake inhibitor effect.

CONCLUSIONS

The identified symptom dimensions are largely congruent with those identified in earlier reports. Patients with OCD vary in their response to treatment with serotonin reuptake inhibitors. The presence of hoarding obsessions and compulsions is associated with poorer response to serotonin reuptake inhibitors.

Reduced design fluency in subclinical obsessive-compulsive subjects

This study examined the verbal and design fluency abilities of 25 subclinical obsessive-compulsive (OC) subjects and 27 noncompulsive control subjects. As hypothesized, the OC group showed reduced design fluency, and design fluency was also negatively correlated with obsessionality. These results provide further evidence for the involvement of the right corticostriatal systems in the mediation of OC behaviors, extending the findings to individuals with subclinical symptoms.

Neuropsychological functioning in a subclinical obsessive-compulsive sample

BACKGROUND

Previous neuropsychological research has suggested that the study of psychometrically defined subclinical samples might be a valid approach to understand the underlying pathophysiology of obsessive-compulsive disorder (OCD). This approach has the potential benefit of overcoming some of the methodological problems linked to the use of clinical samples.

METHODS

A group of subclinical obsessive-compulsive (OC) subjects (n = 35), selected on the basis of their scores on the Padua Inventory, and a control group were assessed on executive functioning tasks and other neuropsychological tests which have been demonstrated to be impaired in clinical OCD patients and/or in those with several basal ganglia disorders.

RESULTS

Subclinical OC subjects needed significantly more moves than controls to reach the solution criteria on the Tower of Hanoi puzzle, and performance on this test was positively correlated with total score and the Checking factor of the Padua Inventory. There were no between-group differences on the other frontal lobe tests.

CONCLUSIONS

The results suggest that deficits in manipulating spatial information might be basic in OCD, and are congruent with the involvement of the frontostriatal circuits in the disorder.

Four-year remission of transsexualism after comorbid obsessive-compulsive disorder improved with self-exposure therapy. Case report

BACKGROUND

There has been no report of comorbid transsexualism and obsessive-compulsive disorder (OCD) or of their differential course over follow-up.

METHOD

Such comorbidity and follow-up are documented in a case report.

RESULTS

A man who had been transsexual and homosexual since early adolescence developed severe OCD at age 40 as he became depressed when his mother, to whom he was very close, died. Two years later he was referred for his OCD. He refused treatment for his transsexualism. As his OCD and mood improved with self-exposure therapy, his transsexualism and homosexuality remitted also. Four years later depression and transsexualism recurred and remained to six-year follow-up despite full remission in OCD continuing throughout.

CONCLUSIONS

The sequence is like that in other cases in whom unusual sexual behaviour remitted for years after comorbid disorders improved with various treatments, or after circumstances changed.

Hemispheric functional imbalance in a sub-clinical obsessive-compulsive sample assessed by the Continuous Performance Test, Identical Pairs version

Obsessive-compulsive disorder (OCD) sufferers have long been observed to give excessive consideration to normally ignored exogenous and endogenous stimuli. This over-focused attention concerning their symptoms has led researchers to experimentally investigate the attentional mechanisms involved in this disorder and its psychobiological basis. Previous psychometric and neuropsychological research has demonstrated the validity of the sub-clinical analogue in the study of the mechanisms underlying OCD. In this study, 71 introductory university students were recruited from an original pool of 450 people on the basis of their scores on the Spanish version of the Padua Inventory. A high obsessive group (n = 35) was compared with a control group (n = 36) on a standard sustained attention task: the Continuous Performance Test, Identical Pairs version (CPT-IP). The results showed a significant interaction effect between CPT-IP subscales (verbal and spatial) and group membership. This effect was more evident among men. The results were unrelated to general intelligence, depression, anxiety, personality or motivational factors. These findings support the hypothesis that neuropsychological deficits in OCD may be related to a hemispheric functional imbalance rather than to a lateralised dysfunction of a particular hemisphere.