Symptom subtypes of obsessive-compulsive disorder: are they relevant for treatment?

A network analysis of obsessive-compulsive symptoms and their comorbidity with other disorders

OBJECTIVES

To improve our understanding of the heterogeneity of obsessive-compulsive disorder (OCD) and its comorbidity with other disorders by using network analysis.

METHODS

An existing data base of 257 participants with a primary diagnosis of OCD and whose symptoms were evaluated using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was subjected to network analysis.

RESULTS

The analysis revealed eight clusters of characteristics. Two clusters were too small in numbers to reach any meaningful conclusion. The other six clusters included patients with: 1) contamination and cleaning symptoms with little comorbidity; 2) high prevalence checking symptoms with comorbid depression and anxiety disorders; 3) high prevalence contamination and cleaning symptoms with aggressive obsessions and checking compulsions; 4) high prevalence hoarding symptoms with comorbid depression and anxiety; 5) high prevalence impulsive aggressive, sexual and checking symptoms, hair-pulling and comorbid body dysmorphic disorder; and 6) high prevalence hoarding with impulsive aggressive and checking symptoms with comorbid alcohol use disorder and psychosis.

CONCLUSIONS

This study highlights the potential role of comorbidity. Contamination/cleaning symptoms were observed to have less psychiatric comorbidity. Symmetry/ordering symptoms did not feature prominently in the symptom clusters, whilst checking compulsions were common to multiple clusters.

Development and validation of a machine learning model to predict cognitive behavioral therapy outcome in obsessive-compulsive disorder using clinical and neuroimaging data

Cognitive behavioral therapy (CBT) is a first-line treatment for obsessive-compulsive disorder (OCD), but clinical response is difficult to predict. In this study, we aimed to develop predictive models using clinical and neuroimaging data from the multicenter Enhancing Neuro-Imaging and Genetics through Meta-Analysis (ENIGMA)-OCD consortium. Baseline clinical and resting-state functional magnetic imaging (rs-fMRI) data from 159 adult patients aged 18-60 years (88 female) with OCD who received CBT at four treatment/neuroimaging sites were included. Fractional amplitude of low frequency fluctuations, regional homogeneity and atlas-based functional connectivity were computed. Clinical CBT response and remission were predicted using support vector machine and random forest classifiers on clinical data only, rs-fMRI data only, and the combination of both clinical and rs-fMRI data. The use of only clinical data yielded an area under the ROC curve (AUC) of 0.69 for predicting remission (p=0.001). Lower baseline symptom severity, younger age, an absence of cleaning obsessions, unmedicated status, and higher education had the highest model impact in predicting remission. The best predictive performance using only rs-fMRI was obtained with regional homogeneity for remission (AUC=0.59). Predicting response with rs-fMRI generally did not exceed chance level. Machine learning models based on clinical data may thus hold promise in predicting remission after CBT for OCD, but the predictive power of multicenter rs-fMRI data is limited.

Individualized functional connectome abnormalities obtained using two normative model unveil neurophysiological subtypes of obsessive compulsive disorder

The high heterogeneity observed among patients with obsessive-compulsive disorder (OCD) underscores the need to identify neurophysiological OCD subtypes to facilitate personalized diagnosis and treatment. In this study, our aim was to identify potential OCD subtypes based on individualized functional connectome abnormalities. We recruited a total of 99 patients with OCD and 104 healthy controls (HCs) matched for demographic characteristics. Individualized functional connectome abnormalities were obtained using normative models of functional connectivity strength (FCS) and used as features to unveil OCD subtypes. Sensitivity analyses were conducted to assess the reproducibility and robustness of the clustering outcomes. Patients exhibited significant intersubject heterogeneity in individualized functional connectome abnormalities. Two subtypes with distinct patterns of FCS abnormalities relative to HCs were identified. Subtype 1 patients primarily exhibited significantly decreased FCS in regions including the frontal gyrus, insula, hippocampus, and precentral/postcentral gyrus, whereas subtype 2 patients demonstrated increased FCS in widespread brain regions. When all patients were combined, no significant differences were observed. Additionally, the identified subtypes showed significant differences in age of onset. Furthermore, sensitivity analyses confirmed the reproducibility of our subtyping results. In conclusion, the identified OCD subtypes shed new light on the taxonomy and neurophysiological heterogeneity of OCD.

Amelioration of obsessive-compulsive disorder by intracellular acidification of cortical neurons with a proton pump inhibitor

Obsessive-compulsive disorder (OCD) is a highly prevalent neuropsychiatric disorder poorly controlled with pharmacological treatment because of the wide variation in symptom patterns. We analysed real-world data on adverse self-reports and insurance claims to identify a novel therapeutic target for OCD. We found that dopamine D2 receptor (D2R) agonists increased the incidence of OCD-like symptoms, which were suppressed by the concomitant use of proton pump inhibitors (PPIs). Further, OCD-like repetitive and habitual behaviours were observed in mice repeatedly injected with a D2R agonist, quinpirole. However, these abnormalities were suppressed by short-term PPI treatment. In quinpirole-treated mice, PPI inhibited pyramidal neuron hyperactivity in the lateral orbitofrontal cortex, a region where the P-type proton pump gene Atp4a is abundantly expressed. In primary cultured cortical neurons, short-term PPI treatment lowered intracellular pH and decreased firing activity, which was mimicked by Atp4a knockdown. Our findings show that inhibition of P-type proton pumps may be a novel therapeutic strategy for OCD.

Prevalence and psychopathology features of mental rituals in patients with obsessive-compulsive disorder: A descriptive exploratory study of 1001 patients

INTRODUCTION

Mental rituals (MR) are compulsions with no overt behavioural or motoric signs. It is presently unclear whether MR found in obsessive-compulsive disorder are associated with a distinctive clinical profile.

OBJECTIVES

The main objectives of this paper were to assess the prevalence and psychopathological correlates of mental rituals in a large sample of OCD patients.

METHODS

This exploratory case-control study compared 519 patients with versus 447 without MR in terms of sociodemographics, presence and severity of obsessive-compulsive symptoms, psychiatric comorbidities, sensory phenomena, suicidality, and insight.

RESULTS

Current MR were found in 51.8%, while lifetime MR were found in 55.4% of the sample. The multiple logistic regression model determined that the most relevant clinical factors independently associated with current MR in OCD patients were the absence of any sensory phenomena and the presence of lifetime suicide ideation.

CONCLUSION

Due to its relation to OCD clinical aspects, MR are a frequent feature among OCD patients. It also seems to be associated with a range of features that are probably relevant for treatment, especially sensory phenomena and suicidality.

The relationship between obsessive-compulsive disorder symptom subtypes and social adjustment

Background

Although it has been widely established that poor social functioning is a characteristic of obsessive-compulsive disorder (OCD), little research has examined the relationship between OCD symptom subtypes and domains of social functioning. Thus, the present study sought to examine the specific ways in which impairment in social adjustment occurs in each symptom subtype of OCD.

Methods

A total of 325 adult participants with a primary diagnosis of OCD were included in the study. Hierarchical linear regressions were used to compare the extent to which OCD symptom subtypes predicted social adjustment domains after controlling for OCD and depression severity.

Results

Hoarding was shown to be significantly associated with work functioning. Whereas both contamination and symmetry subtypes were significantly associated with social functioning, only the contamination subtype was associated with functioning within the family unit. The symptom subtypes of doubt and taboo thoughts were not significantly associated with any domains of social adjustment.

Conclusion

Consistent with previous research, our results suggest a differential impact of OCD symptom subtypes on social adjustment. They offer important implications for the specific domains to target in treatment for different symptom subtypes.

Initial evaluation of a therapist-supported online cognitive therapy self-help for patients with taboo obsessions

OBJECTIVES

The current study evaluated the feasibility of an internet-delivered cognitive therapy (I-CT) in a self-help format with minimal therapist support for patients with obsessive-compulsive disorder (OCD) with primary taboo obsessions. Specifically, the aims were to investigate (1) whether participants were able to grasp and apply the internet-delivered cognitive framework to their own situation; (2) whether they had clinically meaningful reductions of OCD symptom severity; and (3) whether reduced negative appraisals (hypothesized mechanism of change in CT) preceded reductions in OCD symptom severity.

METHOD

Nineteen OCD patients with primary taboo obsessions, recruited from an OCD clinic or self-referrals, received the I-CT intervention for 10 weeks. I-CT did not contain any systematic exposure or response prevention.

RESULTS

Adherence and engagement with the intervention was high. Most participants (n = 13, 68%) understood and successfully applied the cognitive model to their own situation. Within-group analyses showed large reductions in OCD symptom severity at post-treatment (bootstrapped within group d = 1.67 [95% CI; 0.67 to 2.66]) measured with the Yale-Brown Obsessive-Compulsive Scale. The gains were maintained at the 6-month follow-up. Post-hoc analyses revealed that the large reductions in OCD symptom severity were driven by the participants who understood the cognitive model. Reductions in negative appraisals predicted subsequent reductions in OCD symptom severity during treatment.

CONCLUSION

It is possible to adapt a purely cognitive intervention to a digital guided self-help format and to achieve both cognitive change and meaningful symptom reduction. The results require confirmation in a randomized clinical trial.

The global assessment of OCD

Obsessive Compulsive Disorder (OCD) is a common mental disorder that often causes great sufferance, with substantial impairment in social functioning and quality of life and affects family and significant relationships. Notwithstanding its severity, OCD is often not adequately diagnosed, or it is diagnosed with delay, leading often to a long latency between onset of the OCD symptoms and the start of adequate treatments. Several factors contribute to the complexity of OCD's clinical picture: early age of onset, chronic course, heterogeneity of symptoms, high rate of comorbidity with other psychiatric disorders, slow or partial response to therapy. Therefore, it is of primary importance for clinicians involved in diagnosing OCD, to assess all aspects of the disorder. This narrative review focuses on the global assessment of OCD, highlighting crucial areas to explore, pointing out the clinical features which are relevant for the treatment of the disorder, and giving an overview of the psychometric tools that can be useful during the screening procedure.

Functional Connectivity within the Frontal–Striatal Network Differentiates Checkers from Washers of Obsessive-Compulsive Disorder

Background: Obsessive-compulsive disorder (OCD) is a psychiatric disorder with high clinical heterogeneity manifested by the presence of obsessions and/or compulsions. The classification of the symptom dimensional subtypes is helpful for further exploration of the pathophysiological mechanisms underlying the clinical heterogeneity of OCD. Washing and checking symptoms are the two major symptom subtypes in OCD, but the neural mechanisms of the different types of symptoms are not yet clearly understood. The purpose of this study was to compare regional and network functional alterations between washing and checking OCD based on resting-state functional magnetic resonance imaging (rs-fMRI). Methods: In total, 90 subjects were included, including 15 patients in the washing group, 30 patients in the checking group, and 45 healthy controls (HCs). Regional homogeneity (ReHo) was used to compare the differences in regional spontaneous neural activity among the three groups, and local indicators were analyzed by receiver operating characteristic (ROC) curves as imaging markers for the prediction of the clinical subtypes of OCD. Furthermore, differently activated local brain areas, as regions of interest (ROIs), were used to explore differences in altered brain functioning between washing and checking OCD symptoms based on a functional connectivity (FC) analysis. Results: Extensive abnormalities in spontaneous brain activity involving frontal, temporal, and occipital regions were observed in the patients compared to the HCs. The differences in local brain functioning between checking and washing OCD were mainly concentrated in the bilateral middle frontal gyrus, right supramarginal gyrus, right angular gyrus, and right inferior occipital gyrus. The ROC curve analysis revealed that the hyperactivation right middle frontal gyrus had a better discriminatory value for checking and washing OCD. Furthermore, the seed-based FC analysis revealed higher FC between the left medial superior frontal gyrus and right caudate nucleus compared to that in the healthy controls. Conclusions: These findings suggest that extensive local differences exist in intrinsic spontaneous activity among the checking group, washing group, and HCs. The neural basis of checking OCD may be related to dysfunction in the frontal–striatal network, which distinguishes OCD from washing OCD.

Are the symptom dimensions a predictor of short-term response to pharmacotherapy in pediatric obsessive-compulsive disorder? A retrospective cohort study

BACKGROUND

Obsessive-compulsive disorder (OCD) symptom dimensions respond differently to behavioral and pharmacological interventions, and some dimensions are reported to be more resistant to treatment.

AIM

We aimed to investigate the responses of three symptom dimensions (harm/sexual, symmetry/hoarding, and contamination/cleaning) to serotonin reuptake inhibitor (SRI) therapy in pediatric OCD.

METHODS

Children who were between 6 and 17 years old, diagnosed with OCD according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, followed up at our clinic for at least 3 months, and received SRI treatment were included in our study. Response to treatment was assessed using the Clinical Global Impressions scale. Predictors of treatment response were analyzed using regression models.

RESULTS

Of the 102 children with a mean age of 11.84 ± 2.87 years, 57.8% were male and the mean follow-up period was 12.39 ± 9.55 months. The overall response rate to pharmacotherapy was 66.7%. Patients with symmetry/hoarding symptoms [relative risk (RR) = 0.66, 95% confidence interval (CI) (0.12-0.79), P = 0.015] did not respond as well to SRIs. Besides, adolescent age (RR = 0.65, 95% CI (0.10-0.73), P = 0.01) was associated with a less favorable SRI response.

CONCLUSION

This study shows that symptom dimensions are one of the factors predicting response to pharmacotherapy in pediatric OCD. It is hypothesized that considering the dimensions is important to plan more appropriate treatment and provide more accurate prognostic information when assessing children with OCD.

Two distinct subtypes of obsessive compulsive disorder revealed by a framework integrating multimodal neuroimaging information

Patients with obsessive compulsive disorder (OCD) exhibit tremendous heterogeneity in structural and functional neuroimaging aberrance. However, most previous studies just focus on group‐level aberrance of a single modality ignoring heterogeneity and multimodal features. On that account, we aimed to uncover OCD subtypes integrating structural and functional neuroimaging features with the help of a multiview learning method and examined multimodal aberrance for each subtype. Ninety‐nine first‐episode untreated patients with OCD and 104 matched healthy controls (HCs) undergoing structural and functional MRI were included in this study. Voxel‐based morphometric and amplitude of low‐frequency fluctuation (ALFF) were adopted to assess gray matter volumes (GMVs) and the spontaneous neuronal fluctuations respectively. Structural/functional distance network was obtained by calculating Euclidean distance between pairs of regional GMVs/ALFF values across patients. Similarity network fusion, one of multiview learning methods capturing shared and complementary information from multimodal data sources, was used to fuse multimodal distance networks into one fused network. Then spectral clustering was adopted to categorize patients into subtypes. As a result, two robust subtypes were identified. These two subtypes presented opposite GMV aberrance and distinct ALFF aberrance compared with HCs while shared indistinguishable clinical and demographic features. In addition, these two subtypes exhibited opposite structure–function difference correlation reflecting distinct adaptive modifications between multimodal aberrance. Altogether, these results uncover two objective subtypes with distinct multimodal aberrance and provide a new insight into taxonomy of OCD.

Two distinct subtypes of obsessive compulsive disorder revealed by heterogeneity through discriminative analysis

Neurobiological heterogeneity in obsessive compulsive disorder (OCD) is understudied leading to conflicting neuroimaging findings. Therefore, we investigated objective neuroanatomical subtypes of OCD by adopting a newly proposed method based on gray matter volumes (GMVs). GMVs were derived from T1‐weighted anatomical images of patients with OCD (n = 100) and matched healthy controls (HCs; n = 106). We first inquired whether patients with OCD presented higher interindividual variability HCs in terms of GMVs. Then, we identified distinct subtypes of OCD by adopting heterogeneity through discriminative analysis (HYDRA), where regional GMVs were treated as features. Patients with OCD presented higher interindividual variability than HCs, suggesting a high structural heterogeneity of OCD. HYDRA identified two distinct robust subtypes of OCD presenting opposite neuroanatomical aberrances compared with HCs, while sharing indistinguishable clinical and demographic features. Specifically, Subtype 1 exhibited widespread increased GMVs in cortical and subcortical regions, including the orbitofrontal gyrus, right anterior insula, bilateral hippocampus, and bilateral parahippocampus and cerebellum. Subtype 2 demonstrated overall decreased GMVs in regions such as the orbitofrontal gyrus, right anterior insula, and precuneus. When mixed together, none of patients presented significant differences compared with HCs. In addition, the total intracranial volume of Subtype 2 was significantly correlated with the total score of the Yale–Brown Obsessive Compulsive Scale while that of Subtype 1 was not. These results identified two distinct neuroanatomical subtypes, providing a possible explanation for conflicting neuroimaging findings, and proposed a potential objective taxonomy contributing to precise clinical diagnosis and treatment in OCD.

Differentiation of 2 Obsessive-Compulsive Disorder Subgroups with Regard to Demographic and Phenomenological Characteristics Combining Multiple Correspondence and Latent Class Analysis

INTRODUCTION

Classic factor analysis of obsessive-compulsive disorder (OCD) dimensions and attempts to identify valid subgroups have not yet produced definitive conclusions.

OBJECTIVE AND METHODS

This study aims to examine possible homogeneous subgrouping of demographic and phenomenological characteristics in 134 treatment-seeking OCD patients. A combination of multiple correspondence analysis (MCA) and latent class analysis (LCA) was used.

RESULTS

MCA showed 2 distinct subgroups of OCD patients and LCA confirmed this result by a two-class solution. Both analyses demonstrated (a) a clear subgroup of female patients with washing compulsions, obsessions related to contamination, and late age of onset and (b) a subgroup comprised mostly of male patients with earlier onset of OCD, checking rituals, and doubts or aggressive obsessions. Mental, ordering, hoarding compulsions, religious, or sexual obsessions and images appeared exclusively in this subgroup.

CONCLUSIONS

Using 2 different analytic methods, we confirmed at least 2 subgroups in a clinical sample of Greek OCD patients. Future research combining dimensional and latent approaches could facilitate our understanding of the heterogeneous phenotype of OCD.

Out of pocket expenses in obsessive compulsive disorder

Background: Despite anecdotal evidence that the out of pocket costs of OCD can be substantial in some cases, there is no evidence on how many people they affect, or the magnitude of these costs.Aims: This paper explores the type and quantity of out of pocket expenses reported by a large sample of adults with OCD.Methods: Data on out of pocket expenses were collected from participants taking part in the OCTET multi-centre randomised controlled trial. Participants were aged 18+, meeting DSM-IV criteria for OCD, and scoring 16+ on the Yale Brown Obsessive Compulsive Scale. Individual-level resource use data including a description and estimated cost of out of pocket expenses were measured using an adapted version of the Adult Service Use Schedule (AD-SUS): a questionnaire used to collect data on resource use.Results: Forty-five percent (208/465) reported out of pocket expenses due to their OCD. The mean cost of out of pocket expenses was £19.19 per week (SD £27.56 SD), range £0.06-£224.00.Conclusions: Future economic evaluations involving participants with OCD should include out of pocket expenses, but careful consideration of alternative approaches to the collection and costing of this data is needed.

Pharmacotherapy for Hoarding Disorder: How did the Picture Change since its Excision from OCD?

This brief review deals with the various issues that contributed to the creation of the new Diagnostic and Statistical Manual condition of hoarding disorder (HD) and attempts at reviewing its pharmacotherapy. It appears that after the newly founded diagnosis appeared in the literature as an autonomous entity, distinct from obsessive-compulsive disorder, drug trials are not being conducted and the disorder is left in the hands of psychotherapists, who on their part, report fair results in some core dimensions of HD. The few trials on HD specifically regard the serotonin-noradrenaline reuptake inhibitor venlafaxine, and, possibly due to the suggestion of a common biological background of HD with attention-deficit/hyperactivity disorder, the psychostimulant methylphenidate and the noradrenaline reuptake inhibitor atomoxetine. For all these drugs, positive results have been reported, but the evidence level of these studies is low, due to small samples and non-blind designs. Regretfully, there are currently no future studies aiming at seriously testing drugs in HD.

A comparison of cluster and factor analytic techniques for identifying symptom-based dimensions of obsessive-compulsive disorder

A growing body of literature suggests that obsessive-compulsive disorder (OCD) is a heterogeneous condition. The studies investigating symptom dimensions have been limited by numerous methodological differences and sample characteristics. The purpose of this study was to compare the two most commonly applied statistical techniques used in addressing this question in the same large cohort of individuals with OCD. Both cluster analysis and factor analysis were used to examine OCD symptom data as measured by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) Symptom Checklist for 355 individuals with a primary diagnosis of OCD. The factor analysis revealed a three-factor model best described as symmetry obsessions/ordering compulsions, contamination obsessions/cleaning compulsions and aggressive obsessions/checking compulsions. In contrast, the cluster analysis yielded a stable four-cluster solution best described as symmetry obsessions/ordering compulsions, contamination obsessions/cleaning compulsions, aggressive-somatic-religious obsessions/checking compulsions and a mixed symptom profile. Although there was overlap in the models resulting from these two statistical approaches, cluster analysis better captured the dimensional nature of OCD by demonstrating the prevalence of symptom categories in each subgroup. Though both analyses are capable of providing similar outputs, the validity of these results is limited given the input of a priori symptom categories from the Y-BOCS.

Transcranial direct current stimulation in obsessive-compulsive disorder: an update in electric field modeling and investigations for optimal electrode montage

Introduction: Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation intervention that has been investigated for several psychiatric disorders, including Obsessive-Compulsive Disorder (OCD). As there are several candidate brain regions for targeting OCD relevant networks, clinical studies using tDCS have considerably varied in terms of the electrode montages used. Computer modeling of electric field currents induced by tDCS can help guiding the research of relevant targets for OCD. In this review, the authors used this tool to investigate targeted brain areas from previous studies of tDCS in OCD. Areas covered: A literature search for articles with the keywords 'tDCS', 'Transcranial Direct Current Stimulation' and 'Obsessive Compulsive Disorder' was conducted to identify relevant publications. For comparing different electrode montages, electric field (EF) models were performed using high-resolution brain scan templates. Authors found 13 studies mostly showing an improvement in OCD symptoms. The electrode montages varied considerably between studies. Nonetheless, two main patterns of EFs could be identified: 'focal montages', with EFs concentrated in the prefrontal cortex, and 'diffuse montages', with widespread EFs over cortical areas. Expert opinion: Electric field simulation can guide future clinical trials in psychiatry, using personalized tDCS montages with distinct electrode positioning according to clusters of symptoms.

An Adenosine A2A Receptor Antagonist Improves Multiple Symptoms of Repeated Quinpirole-Induced Psychosis

Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder characterized by the repeated rise of concerns (obsessions) and repetitive unwanted behavior (compulsions). Although selective serotonin reuptake inhibitors (SSRIs) is the first-choice drug, response rates to SSRI treatment vary between symptom dimensions. In this study, to find a therapeutic target for SSRI-resilient OCD symptoms, we evaluated treatment responses of quinpirole (QNP) sensitization-induced OCD-related behaviors in mice. SSRI administration rescued the cognitive inflexibility, as well as hyperactivity in the lateral orbitofrontal cortex (lOFC), while no improvement was observed for the repetitive behavior. D₂ receptor signaling in the central striatum (CS) was involved in SSRI-resistant repetitive behavior. An adenosine A_2A antagonist, istradefylline, which rescued abnormal excitatory synaptic function in the CS indirect pathway medium spiny neurons (MSNs) of sensitized mice, alleviated both of the QNP-induced abnormal behaviors with only short-term administration. These results provide a new insight into therapeutic strategies for SSRI-resistant OCD symptoms and indicate the potential of A_2A antagonists as a rapid-acting anti-OCD drug.

Whole-Brain Multimodal Neuroimaging Model Using Serotonin Receptor Maps Explains Non-linear Functional Effects of LSD

Understanding the underlying mechanisms of the human brain in health and disease will require models with necessary and sufficient details to explain how function emerges from the underlying anatomy and is shaped by neuromodulation. Here, we provide such a detailed causal explanation using a whole-brain model integrating multimodal imaging in healthy human participants undergoing manipulation of the serotonin system. Specifically, we combined anatomical data from diffusion magnetic resonance imaging (dMRI) and functional magnetic resonance imaging (fMRI) with neurotransmitter data obtained with positron emission tomography (PET) of the detailed serotonin 2A receptor (5-HT_2AR) density map. This allowed us to model the resting state (with and without concurrent music listening) and mechanistically explain the functional effects of 5-HT_2AR stimulation with lysergic acid diethylamide (LSD) on healthy participants. The whole-brain model used a dynamical mean-field quantitative description of populations of excitatory and inhibitory neurons as well as the associated synaptic dynamics, where the neuronal gain function of the model is modulated by the 5-HT_2AR density. The model identified the causative mechanisms for the non-linear interactions between the neuronal and neurotransmitter system, which are uniquely linked to (1) the underlying anatomical connectivity, (2) the modulation by the specific brainwide distribution of neurotransmitter receptor density, and (3) the non-linear interactions between the two. Taking neuromodulatory activity into account when modeling global brain dynamics will lead to novel insights into human brain function in health and disease and opens exciting possibilities for drug discovery and design in neuropsychiatric disorders.

Does neuropsychological performance in OCD relate to different symptoms? A meta-analysis comparing the symmetry and obsessing dimensions

BACKGROUND

Investigations of neuropsychological functioning in obsessive-compulsive disorder (OCD) have produced mixed results for deficits in executive functioning (EF), attention, and memory. One potential explanation for varied findings may relate to the heterogeneity of symptom presentations, and different clinical or neurobiological characteristics may underlie these different symptoms.

METHODS

We investigated differences in neuropsychological functioning between two symptoms groups, obsessing/checking (O/C) and symmetry/ordering (S/O), based on data suggesting an association with different motivations: harm avoidance and incompleteness, respectively. Ten studies (with 628 patients) were included and each investigation assessed at least one of 14 neuropsychological domains.

RESULTS

The S/O domain demonstrated small, negative correlations with overall neuropsychological functioning, performance in EF, memory, visuospatial ability, cognitive flexibility, and verbal working memory. O/C symptoms demonstrated small, negative correlations with memory and verbal memory performance. A comparison of functioning between symptom groups identified large effect sizes showing that the S/O dimension was more strongly related to poorer neuropsychological performance overall, and in the domains of attention, visuospatial ability, and the subdomain of verbal working memory.

CONCLUSIONS

Findings support existing evidence suggesting that different OCD symptoms, and their associated core motivations, relate to unique patterns of neuropsychological functioning, and, potentially dysfunction in different neural circuits.

A critical appraisal of heterogeneity in Obsessive-Compulsive Disorder using symptom-based clustering analysis

Obsessive-compulsive disorder (OCD) encompasses a broad range of symptoms and is commonly considered a heterogeneous condition. Attempts were made to define discrete OCD subtypes using a range of symptom-based methods including factor and cluster analyses. The present study aims to find the most appropriate clustering model based on Yale-Brown obsessive-compulsive scale (YBOCS) checklist explaining OCD heterogeneity. Five different clustering algorithms (FCM, K-means, Ward, Ward+K-means and Complete) applied on YBOCS symptoms of 216 patients with OCD. Data studied as four different sets including item-level raw data, item-based factor scores, category-level raw data and category-based factor scores and clustering results for 2 to 6 cluster solutions evaluated by four clustering indices (Davies-Bouldin, Calinski-Harabasz, Silhouettes and Dunn indices). Two-cluster solution was detected as the most appropriate model for item and category-based clustering analyses of YBOCS checklist symptoms. Patients in each cluster were characterized based on their clinical and demographic properties and results showed that they had similar patterns of symptoms but in different severities. Heterogenity of OCD based on the YBOCS-symptoms has been challenged as OCD patients were classified based on their symptom severity not their symptom patterns. More investigations need to find appropriate measures explaining OCD heterogeneity with clinical importance.

Psychopharmacological treatment differences in autogenous and reactive obsessions: A retrospective chart review

BACKGROUND

Identification of homogeneous subgroups of obsessive compulsive disorder (OCD) patients may have important implications for improving effective treatment options. It has been proposed that obsessive thoughts can be classified into two subtypes, i.e. autogenous and reactive obsessions. Although it has been shown that patients with autogenous obsessions may display a worse response to treatment, no studies have yet addressed whether there is a different need for the psychopharmacological treatment options in the subtypes of OCD patients.

AIM

To investigate the clinical characteristics and treatment differences between autogenous (A-OCD) and reactive (R-OCD) subtypes of OCD patients.

METHODS

Both OCD subgroups (n = 50 for A-OCD, n = 130 for R-OCD) were compared with each other in terms of their demographic and clinical parameters. Odds ratio values for gender, treatment options, co-morbidity, severity of OCD, and response to treatment were computed. Multivariate hierarchical regression analyses were performed to identify any predictors for treatment options, severity of OCD, and response to treatment.

RESULTS

Our results indicated that the A-OCD and R-OCD groups differed from each other on some demographic and clinical variables in addition to their psychopharmacological treatment needs. Patients in the A-OCD group were found to be prescribed an atypical antipsychotic 2.3 times more likely than the R-OCD group. The odds for a combination treatment, or the improvement of OCD symptoms from baseline levels did not differ between the two subtypes of obsession groups.

CONCLUSIONS

Autogenous and reactive subtypes of obsessions may need to be offered different psychopharmacological treatment options.

A meta-analysis of the response of pathological hoarding to pharmacotherapy

This meta-analysis aimed to identify all studies that have assessed treatment response for pathological hoarding treated with pharmacological agents. Seven studies were identified with a total of 92 participants. Most participants had a diagnosis of obsessive-compulsive disorder. Studies assessed response to serotonin-reuptake inhibitors (SRIs); venlafaxine; methylphenidate; and augmentation of SRIs with quetiapine, minocycline and naltrexone. More than half (ER=0.58, 95% CI=0.37-0.76) of the participants treated with pharmacotherapy responded. This study encourages us to consider the use of SRIs in patients with hoarding disorder. The study also encourages more studies of pharmacotherapy for pathological hoarding, noting that these studies should use validated outcome measures that specifically assess pathological hoarding and novel agents that target the unique neurobiological correlates of pathological hoarding.

Are 5-HT3 antagonists effective in obsessive-compulsive disorder? A systematic review of literature

OBJECTIVE

The purpose of this literature database search-based review was to critically consider and evaluate the findings of literature focusing on efficacy and safety of 5-HT3 antagonists in the treatment of obsessive-compulsive disorder (OCD), so as to test whether preclinical data match clinical therapeutic trials.

DESIGN

The PubMed database has been searched for papers on 5-HT3 antagonists and OCD in humans and for animal models of OCD and 5-HT3 receptors.

RESULTS

Of the clinically tested 5-HT3 receptor antagonists, ondansetron has been used to treat OCD in five therapeutic studies, whereas granisetron only in one recent trial. Both showed some efficacy in open studies and superiority to placebo in double-blind studies, along with fair safety. No animal OCD model directly implicated 5-HT3 receptors.

CONCLUSIONS

Overall, results indicate some utility, but the available literature is too scanty to allow for valid conclusions to be drawn. The mismatch between animal models of obsessive-compulsive disorder and clinical data with 5-HT3 antagonists needs more clinical data to ensure that it is not an artefact.

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

BACKGROUND

In the quest to unravel the heterogeneity of obsessive-compulsive disorder (OCD), an increasing number of factor analytic studies are recognising unacceptable/taboo thoughts as one of the symptom dimensions of OCD.

AIMS

This study aims to examine the characteristics associated with unacceptable/taboo thoughts.

METHODS

Using the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC) with 154 individuals with OCD, obsessive-compulsive symptoms were subjected to principal components analysis. The characteristics associated with the resulting symptom dimensions were then assessed using logistic and linear regression techniques.

RESULTS

Unacceptable/taboo thoughts comprised of sexual, religious and impulsive aggressive obsessions, and mental rituals. Higher scores on an unacceptable/taboo thoughts symptom dimension were predicted by higher Y-BOCS obsession subscores, Y-BOCS time preoccupied by obsessions scores, Y-BOCS distress due to obsessions scores, importance of control of thought ratings, male gender, and having had treatment prior to entering into the study. Unacceptable/taboo thoughts were also predicted by greater levels of hostility, and a past history of non-alcohol substance dependence.

CONCLUSIONS

An unacceptable/taboo thought symptom dimension of OCD is supported by a unique set of associated characteristics that should be considered in the assessment and treatment of individuals with these symptoms.

Juvenile obsessive-compulsive disorder: A case report

Obsessive-compulsive disorder (OCD) is one of the more disabling and potentially chronic anxiety disorders that occurs in several medical settings. However, it is often under-recognized and under-treated. The condition is now known to be prevalent among children and adolescents. Obsessional images as a symptom occur less frequently than other types of obsessions. In this report, we describe a young boy who presented himself predominantly with obsessional images. The diagnostic and treatment challenges in juvenile OCD are discussed.

The use of psychotropic agents for the symptoms of obsessive-compulsive disorder

OBJECTIVE

To describe the use of psychotropic agents in a sample of subjects with obsessive-compulsive disorder (OCD), and in particular the differences associated with different OCD symptoms.

METHOD

A total of 154 subjects participated in a study assessing OCD symptom subtypes, called the Nepean OCD Study. In addition to a comprehensive evaluation of the subjects' OCD symptoms using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Vancouver Obsessive-Compulsive Inventory (VOCI), and the Sheehan Disability Scale (SDS), the subjects' medication history was recorded. The association between symptom severity, disability, OCD symptom subtypes and the use of psychotropic agents was examined.

RESULTS

Psychotropic medication was taken by 93 (60.4%) participants. In the majority of cases (n=55, 59.1%), selective serotonin reuptake inhibitors (SSRIs) were taken, and of the SSRIs, the most commonly used agent was escitalopram (n=21, 22.6%). Psychotropic agents were more likely to be taken by subjects with higher Y-BOCS and SDS scores. Hoarding was associated with a lower likelihood of psychotropic use, whereas unacceptable/taboo thoughts were associated with an increased likelihood of psychotropic and antipsychotic use.

CONCLUSION

Patients with OCD are more likely to be taking psychotropic agents if they have a more severe illness, greater disability and more prominent unacceptable/taboo thoughts.

The nature and correlates of avoidance in obsessive-compulsive disorder

OBJECTIVES

Avoidance in obsessive-compulsive disorder (OCD) has been neglected by research. This study aimed (i) to collect information on the nature and frequency of avoidance in people with OCD and ascertain the types of obsessions related to avoidance; (ii) compare OCD individuals with and without avoidance, and (iii) determine predictors of avoidance in people with OCD.

METHOD

A total of 124 OCD adults underwent a comprehensive assessment. Participants were asked whether they engaged in any avoidance behaviour because of their OCD, and the nature and number of instances of such avoidance were recorded. The instances of avoidance were grouped according to the type of obsession and compulsion that they were related to.

RESULTS

A total of 74 (59.7%) participants reported OCD-related avoidance. Avoidance was most commonly related to contamination obsessions. Almost 80% of all contamination obsessions and more than 50% of all aggressive obsessions were associated with avoidance, and contamination obsessions were significantly more common among the participants with avoidance. In contrast, very few obsessions about a need to collect and keep objects and obsessions about a need for ordering, arranging and doing things right or in an exact way were associated with avoidance; these types of obsessions were also significantly more common among the participants without avoidance. The strongest predictor of avoidance was the presence of contamination obsessions. Participants with avoidance had a significantly more severe OCD than those without avoidance.

CONCLUSIONS

Avoidance is common in OCD, and it is particularly frequently associated with contamination obsessions. There is a weak link between avoidance and hoarding and between avoidance and ordering/arranging/symmetry obsessions and compulsions. These results, along with the finding that OCD with avoidance is a more severe illness, have implications for the future diagnostic criteria, description, subtyping and treatment of OCD and for its relationship with other anxiety disorders.

Functions of compulsions in obsessive-compulsive disorder

OBJECTIVES

The key function of compulsions in obsessive-compulsive disorder (OCD) is to alleviate anxiety or distress caused by the obsessions, but compulsions may also have other functions. The main aim of this study was to systematically ascertain what motivates individuals with OCD to perform compulsions.

METHOD

A total of 108 adults with OCD were assessed with the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Functions of Compulsions Interview. The latter instrument elicits the functions of identified compulsions.

RESULTS

The functions of 218 compulsions were identified. The mean number of functions per compulsion in the whole sample was 2.94 and the vast majority of compulsions (85.3%) were performed for more than one reason. The total number of functions of compulsions endorsed for the three main compulsions correlated with Y-BOCS total scores (r = 0.37, p < 0.001). Compulsions were most frequently performed automatically and to decrease distress or anxiety, but there was substantial variation, depending on the type of compulsion. Hoarding was often performed for reasons not related to any other compulsion (involving a perceived need for collected objects), whereas ordering/symmetry/repeating compulsions were frequently performed to achieve a 'just right' feeling. Checking was frequently performed because of the belief that something bad or unpleasant would happen if one failed to check; washing/cleaning compulsions were most frequently performed to decrease distress or anxiety and automatically, and mental compulsions were performed automatically far more often than for other reasons.

CONCLUSIONS

The majority of compulsions have more than one function and they are often performed automatically. The finding of different functions of compulsions in different types of compulsions provides some support to the subtyping of OCD on the basis of obsessions and compulsions. Identifying functions of compulsions allows better understanding of the functional relationship between obsessions and compulsions, which may have implications for cognitive-behavioural therapy of OCD.

Stuck in a rut: rethinking depression and its treatment

The current definition of major depressive disorder (MDD) emerged from efforts to create reliable diagnostic criteria for clinical and research use. However, despite decades of research, the neurobiology of MDD is largely unknown, and treatments are no more effective today than they were 50-70 years ago. Here, we propose that the current conception of depression is misguiding basic and clinical research. Redefinition is necessary and could include a focus on a more narrowly defined set of core symptoms. However, we conclude that depression is better defined as the tendency to enter into, and inability to disengage from, a negative mood state rather than the mood state per se. We also discuss the implications of this revised definition for future clinical and basic research.

Nonclinical obsessive-compulsive symptoms and executive functions in schizophrenia

The impact of nonclinical obsessive-compulsive symptoms (OCS) on neuropsychological functioning in schizophrenia has received little investigation. The authors evaluated whether severity and subtype of OCS are associated with executive functioning in schizophrenia. Twenty-nine patients with schizophrenia and 32 healthy comparison subjects completed questionnaire and performance-based measures of executive functioning. Overall OCS severity in patients was associated with poorer monitoring and cognitive flexibility. Obsessing, hoarding, and checking were related to poorer executive functioning in daily life. Performance-based scores showed few correlations with OCS. Findings indicate that severity of nonclinical OCS subtypes contributes to the heterogeneity of executive functions in schizophrenia.