Genome-wide association study identifies 30 obsessive-compulsive disorder associated loci

Obsessive-compulsive disorder (OCD) affects ~1% of the population and exhibits a high SNP-heritability, yet previous genome-wide association studies (GWAS) have provided limited information on the genetic etiology and underlying biological mechanisms of the disorder. We conducted a GWAS meta-analysis combining 53,660 OCD cases and 2,044,417 controls from 28 European-ancestry cohorts revealing 30 independent genome-wide significant SNPs and a SNP-based heritability of 6.7%. Separate GWAS for clinical, biobank, comorbid, and self-report sub-groups found no evidence of sample ascertainment impacting our results. Functional and positional QTL gene-based approaches identified 249 significant candidate risk genes for OCD, of which 25 were identified as putatively causal, highlighting WDR6, DALRD3, CTNND1 and genes in the MHC region. Tissue and single-cell enrichment analyses highlighted hippocampal and cortical excitatory neurons, along with D1- and D2-type dopamine receptor-containing medium spiny neurons, as playing a role in OCD risk. OCD displayed significant genetic correlations with 65 out of 112 examined phenotypes. Notably, it showed positive genetic correlations with all included psychiatric phenotypes, in particular anxiety, depression, anorexia nervosa, and Tourette syndrome, and negative correlations with a subset of the included autoimmune disorders, educational attainment, and body mass index.. This study marks a significant step toward unraveling its genetic landscape and advances understanding of OCD genetics, providing a foundation for future interventions to address this debilitating disorder.

White matter diffusion estimates in obsessive-compulsive disorder across 1653 individuals: machine learning findings from the ENIGMA OCD Working Group

White matter pathways, typically studied with diffusion tensor imaging (DTI), have been implicated in the neurobiology of obsessive-compulsive disorder (OCD). However, due to limited sample sizes and the predominance of single-site studies, the generalizability of OCD classification based on diffusion white matter estimates remains unclear. Here, we tested classification accuracy using the largest OCD DTI dataset to date, involving 1336 adult participants (690 OCD patients and 646 healthy controls) and 317 pediatric participants (175 OCD patients and 142 healthy controls) from 18 international sites within the ENIGMA OCD Working Group. We used an automatic machine learning pipeline (with feature engineering and selection, and model optimization) and examined the cross-site generalizability of the OCD classification models using leave-one-site-out cross-validation. Our models showed low-to-moderate accuracy in classifying (1) "OCD vs. healthy controls" (Adults, receiver operator characteristic-area under the curve = 57.19 ± 3.47 in the replication set; Children, 59.8 ± 7.39), (2) "unmedicated OCD vs. healthy controls" (Adults, 62.67 ± 3.84; Children, 48.51 ± 10.14), and (3) "medicated OCD vs. unmedicated OCD" (Adults, 76.72 ± 3.97; Children, 72.45 ± 8.87). There was significant site variability in model performance (cross-validated ROC AUC ranges 51.6-79.1 in adults; 35.9-63.2 in children). Machine learning interpretation showed that diffusivity measures of the corpus callosum, internal capsule, and posterior thalamic radiation contributed to the classification of OCD from HC. The classification performance appeared greater than the model trained on grey matter morphometry in the prior ENIGMA OCD study (our study includes subsamples from the morphometry study). Taken together, this study points to the meaningful multivariate patterns of white matter features relevant to the neurobiology of OCD, but with low-to-moderate classification accuracy. The OCD classification performance may be constrained by site variability and medication effects on the white matter integrity, indicating room for improvement for future research.

Right Prefrontal Cortical Thickness Is Associated With Response to Cognitive-Behavioral Therapy in Children With Obsessive-Compulsive Disorder

OBJECTIVE

Cognitive-behavioral therapy (CBT) is considered a first-line treatment for obsessive-compulsive disorder (OCD) in pediatric and adult populations. Nevertheless, some patients show partial or null response. The identification of predictors of CBT response may improve clinical management of patients with OCD. Here, we aimed to identify structural magnetic resonance imaging (MRI) predictors of CBT response in 2 large series of children and adults with OCD from the worldwide ENIGMA-OCD consortium.

METHOD

Data from 16 datasets from 13 international sites were included in the study. We assessed which variations in baseline cortical thickness, cortical surface area, and subcortical volume predicted response to CBT (percentage of baseline to post-treatment symptom reduction) in 2 samples totaling 168 children and adolescents (age range 5-17.5 years) and 318 adult patients (age range 18-63 years) with OCD. Mixed linear models with random intercept were used to account for potential cross-site differences in imaging values.

RESULTS

Significant results were observed exclusively in the pediatric sample. Right prefrontal cortex thickness was positively associated with the percentage of CBT response. In a post hoc analysis, we observed that the specific changes accounting for this relationship were a higher thickness of the frontal pole and the rostral middle frontal gyrus. We observed no significant effects of age, sex, or medication on our findings.

CONCLUSION

Higher cortical thickness in specific right prefrontal cortex regions may be important for CBT response in children with OCD. Our findings suggest that the right prefrontal cortex plays a relevant role in the mechanisms of action of CBT in children.

Associations of medication with subcortical morphology across the lifespan in OCD: Results from the international ENIGMA Consortium

BACKGROUND

Widely used psychotropic medications for obsessive-compulsive disorder (OCD) may change the volumes of subcortical brain structures, and differently in children vs. adults. We measured subcortical volumes cross-sectionally in patients finely stratified for age taking various common classes of OCD drugs.

METHODS

The ENIGMA-OCD consortium sample (1081 medicated/1159 unmedicated OCD patients and 2057 healthy controls aged 6-65) was divided into six successive 6-10-year age-groups. Individual structural MRIs were parcellated automatically using FreeSurfer into 8 regions-of-interest (ROIs). ROI volumes were compared between unmedicated and medicated patients and controls, and between patients taking serotonin reuptake inhibitors (SRIs), tricyclics (TCs), antipsychotics (APs), or benzodiazepines (BZs) and unmedicated patients.

RESULTS

Compared to unmedicated patients, volumes of accumbens, caudate, and/or putamen were lower in children aged 6-13 and adults aged 50-65 with OCD taking SRIs (Cohen's d = -0.24 to -0.74). Volumes of putamen, pallidum (d = 0.18-0.40), and ventricles (d = 0.31-0.66) were greater in patients aged 20-29 receiving APs. Hippocampal volumes were smaller in patients aged 20 and older taking TCs and/or BZs (d = -0.27 to -1.31).

CONCLUSIONS

Results suggest that TCs and BZs could potentially aggravate hippocampal atrophy of normal aging in older adults with OCD, whereas SRIs may reduce striatal volumes in young children and older adults. Similar to patients with psychotic disorders, OCD patients aged 20-29 may experience subcortical nuclear and ventricular hypertrophy in relation to APs. Although cross-sectional, present results suggest that commonly prescribed agents exert macroscopic effects on subcortical nuclei of unknown relation to therapeutic response.

An overview of the first 5 years of the ENIGMA obsessive-compulsive disorder working group: The power of worldwide collaboration

Neuroimaging has played an important part in advancing our understanding of the neurobiology of obsessive-compulsive disorder (OCD). At the same time, neuroimaging studies of OCD have had notable limitations, including reliance on relatively small samples. International collaborative efforts to increase statistical power by combining samples from across sites have been bolstered by the ENIGMA consortium; this provides specific technical expertise for conducting multi-site analyses, as well as access to a collaborative community of neuroimaging scientists. In this article, we outline the background to, development of, and initial findings from ENIGMA's OCD working group, which currently consists of 47 samples from 34 institutes in 15 countries on 5 continents, with a total sample of 2,323 OCD patients and 2,325 healthy controls. Initial work has focused on studies of cortical thickness and subcortical volumes, structural connectivity, and brain lateralization in children, adolescents and adults with OCD, also including the study on the commonalities and distinctions across different neurodevelopment disorders. Additional work is ongoing, employing machine learning techniques. Findings to date have contributed to the development of neurobiological models of OCD, have provided an important model of global scientific collaboration, and have had a number of clinical implications. Importantly, our work has shed new light on questions about whether structural and functional alterations found in OCD reflect neurodevelopmental changes, effects of the disease process, or medication impacts. We conclude with a summary of ongoing work by ENIGMA-OCD, and a consideration of future directions for neuroimaging research on OCD within and beyond ENIGMA.

Antidepressant use and risk of intubation or death in hospitalized patients with COVID-19: A retrospective cohort study of clinical effectiveness

Initial controlled trials of the serotonergic antidepressant fluvoxamine showed promise for treatment of mild to moderate COVID-19 in outpatients, although more recent outpatient data have been less encouraging. Turning to studies of hospitalized patients, a retrospective cohort study by Hoertel and associates in 2021 found a markedly reduced risk of intubation or death among patients hospitalized with COVID-19 who were receiving serotonergic antidepressants at the time of admission vs. those not receiving antidepressants. In an attempt to replicate these latter findings, we performed a similarly designed study of 500 individuals hospitalized with COVID-19 in a large academic hospital system who were taking a serotonergic antidepressant at the time of admission compared with two groups (N = 573 and N = 593) not receiving an antidepressant. In analyses controlling for demographic and clinical variables, we found no significant difference in effect between the antidepressant group and either of the two comparison groups [hazard ratios (95% CI) for intubation or death 1.1 (0.83-1.5) and 1.1 (0.86-1.5); and for death alone 1.3 (0.93-1.8) and 1.1 (0.85-1.7)]. Examining the results of our study, along with those of Hoertel et al. and three additional retrospective cohort studies in inpatients published in the interim, the data permit only very limited conclusions, with the findings on the effect of serotonergic antidepressants ranging from a strongly protective effect to no effect. Although there are numerous threats to validity that might account for this wide range of findings, we could not identify any principal factor or set of factors that could clearly explain the differences.

Specialty knowledge and competency standards for pharmacotherapy for adult obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) affects approximately one person in 40 and causes substantial suffering. Evidence-based treatments can benefit many; however, optimal treatment can be difficult to access. Diagnosis is frequently delayed, and pharmacological and psychotherapeutic interventions often fail to follow evidence-based guidelines. To ameliorate this distressing situation, the International OCD Accreditation Task Force of the Canadian Institute for Obsessive-Compulsive Disorders has developed knowledge and competency standards for specialized treatments for OCD through the lifespan. These are foundational to evidence-based practice and will form the basis for upcoming ATF development of certification/accreditation programs. Here, we present specialty standards for the pharmacological treatment of adult OCD. We emphasize the importance of integrating pharmacotherapy with clear diagnosis, appreciation of complicating factors, and evidence-based cognitive behavioral therapy. Clear evidence exists to inform first- and second-line pharmacological treatments. In disease refractory to these initial efforts, multiple strategies have been investigated, but the evidence is more equivocal. These standards summarize this limited evidence to give the specialist practitioner a solid basis on which to make difficult decisions in complex cases. It is hoped that further research will lead to development of a clear, multi-step treatment algorithm to support each step in clinical decision-making.

Virtual Histology of Cortical Thickness and Shared Neurobiology in 6 Psychiatric Disorders

IMPORTANCE

Large-scale neuroimaging studies have revealed group differences in cortical thickness across many psychiatric disorders. The underlying neurobiology behind these differences is not well understood.

OBJECTIVE

To determine neurobiologic correlates of group differences in cortical thickness between cases and controls in 6 disorders: attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), bipolar disorder (BD), major depressive disorder (MDD), obsessive-compulsive disorder (OCD), and schizophrenia.

DESIGN, SETTING, AND PARTICIPANTS

Profiles of group differences in cortical thickness between cases and controls were generated using T1-weighted magnetic resonance images. Similarity between interregional profiles of cell-specific gene expression and those in the group differences in cortical thickness were investigated in each disorder. Next, principal component analysis was used to reveal a shared profile of group difference in thickness across the disorders. Analysis for gene coexpression, clustering, and enrichment for genes associated with these disorders were conducted. Data analysis was conducted between June and December 2019. The analysis included 145 cohorts across 6 psychiatric disorders drawn from the ENIGMA consortium. The numbers of cases and controls in each of the 6 disorders were as follows: ADHD: 1814 and 1602; ASD: 1748 and 1770; BD: 1547 and 3405; MDD: 2658 and 3572; OCD: 2266 and 2007; and schizophrenia: 2688 and 3244.

MAIN OUTCOMES AND MEASURES

Interregional profiles of group difference in cortical thickness between cases and controls.

RESULTS

A total of 12 721 cases and 15 600 controls, ranging from ages 2 to 89 years, were included in this study. Interregional profiles of group differences in cortical thickness for each of the 6 psychiatric disorders were associated with profiles of gene expression specific to pyramidal (CA1) cells, astrocytes (except for BD), and microglia (except for OCD); collectively, gene-expression profiles of the 3 cell types explain between 25% and 54% of variance in interregional profiles of group differences in cortical thickness. Principal component analysis revealed a shared profile of difference in cortical thickness across the 6 disorders (48% variance explained); interregional profile of this principal component 1 was associated with that of the pyramidal-cell gene expression (explaining 56% of interregional variation). Coexpression analyses of these genes revealed 2 clusters: (1) a prenatal cluster enriched with genes involved in neurodevelopmental (axon guidance) processes and (2) a postnatal cluster enriched with genes involved in synaptic activity and plasticity-related processes. These clusters were enriched with genes associated with all 6 psychiatric disorders.

CONCLUSIONS AND RELEVANCE

In this study, shared neurobiologic processes were associated with differences in cortical thickness across multiple psychiatric disorders. These processes implicate a common role of prenatal development and postnatal functioning of the cerebral cortex in these disorders.

Structural neuroimaging biomarkers for obsessive-compulsive disorder in the ENIGMA-OCD consortium: medication matters

No diagnostic biomarkers are available for obsessive-compulsive disorder (OCD). Here, we aimed to identify magnetic resonance imaging (MRI) biomarkers for OCD, using 46 data sets with 2304 OCD patients and 2068 healthy controls from the ENIGMA consortium. We performed machine learning analysis of regional measures of cortical thickness, surface area and subcortical volume and tested classification performance using cross-validation. Classification performance for OCD vs. controls using the complete sample with different classifiers and cross-validation strategies was poor. When models were validated on data from other sites, model performance did not exceed chance-level. In contrast, fair classification performance was achieved when patients were grouped according to their medication status. These results indicate that medication use is associated with substantial differences in brain anatomy that are widely distributed, and indicate that clinical heterogeneity contributes to the poor performance of structural MRI as a disease marker.

Subcortical Brain Volume, Regional Cortical Thickness, and Cortical Surface Area Across Disorders: Findings From the ENIGMA ADHD, ASD, and OCD Working Groups

OBJECTIVE

Attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and obsessive-compulsive disorder (OCD) are common neurodevelopmental disorders that frequently co-occur. The authors sought to directly compare these disorders using structural brain imaging data from ENIGMA consortium data.

METHODS

Structural T1-weighted whole-brain MRI data from healthy control subjects (N=5,827) and from patients with ADHD (N=2,271), ASD (N=1,777), and OCD (N=2,323) from 151 cohorts worldwide were analyzed using standardized processing protocols. The authors examined subcortical volume, cortical thickness, and cortical surface area differences within a mega-analytical framework, pooling measures extracted from each cohort. Analyses were performed separately for children, adolescents, and adults, using linear mixed-effects models adjusting for age, sex, and site (and intracranial volume for subcortical and surface area measures).

RESULTS

No shared differences were found among all three disorders, and shared differences between any two disorders did not survive correction for multiple comparisons. Children with ADHD compared with those with OCD had smaller hippocampal volumes, possibly influenced by IQ. Children and adolescents with ADHD also had smaller intracranial volume than control subjects and those with OCD or ASD. Adults with ASD showed thicker frontal cortices compared with adult control subjects and other clinical groups. No OCD-specific differences were observed across different age groups and surface area differences among all disorders in childhood and adulthood.

CONCLUSIONS

The study findings suggest robust but subtle differences across different age groups among ADHD, ASD, and OCD. ADHD-specific intracranial volume and hippocampal differences in children and adolescents, and ASD-specific cortical thickness differences in the frontal cortex in adults, support previous work emphasizing structural brain differences in these disorders.

Mapping Cortical and Subcortical Asymmetry in Obsessive-Compulsive Disorder: Findings From the ENIGMA Consortium

BACKGROUND

Lateralized dysfunction has been suggested in obsessive-compulsive disorder (OCD). However, it is currently unclear whether OCD is characterized by abnormal patterns of brain structural asymmetry. Here we carried out what is by far the largest study of brain structural asymmetry in OCD.

METHODS

We studied a collection of 16 pediatric datasets (501 patients with OCD and 439 healthy control subjects), as well as 30 adult datasets (1777 patients and 1654 control subjects) from the OCD Working Group within the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) Consortium. Asymmetries of the volumes of subcortical structures, and of measures of regional cortical thickness and surface areas, were assessed based on T1-weighted magnetic resonance imaging scans, using harmonized image analysis and quality control protocols. We investigated possible alterations of brain asymmetry in patients with OCD. We also explored potential associations of asymmetry with specific aspects of the disorder and medication status.

RESULTS

In the pediatric datasets, the largest case-control differences were observed for volume asymmetry of the thalamus (more leftward; Cohen's d = 0.19) and the pallidum (less leftward; d = -0.21). Additional analyses suggested putative links between these asymmetry patterns and medication status, OCD severity, or anxiety and depression comorbidities. No significant case-control differences were found in the adult datasets.

CONCLUSIONS

The results suggest subtle changes of the average asymmetry of subcortical structures in pediatric OCD, which are not detectable in adults with the disorder. These findings may reflect altered neurodevelopmental processes in OCD.

Performing group-level functional image analyses based on homologous functional regions mapped in individuals

Functional MRI (fMRI) studies have traditionally relied on intersubject normalization based on global brain morphology, which cannot establish proper functional correspondence between subjects due to substantial intersubject variability in functional organization. Here, we reliably identified a set of discrete, homologous functional regions in individuals to improve intersubject alignment of fMRI data. These functional regions demonstrated marked intersubject variability in size, position, and connectivity. We found that previously reported intersubject variability in functional connectivity maps could be partially explained by variability in size and position of the functional regions. Importantly, individual differences in network topography are associated with individual differences in task-evoked activations, suggesting that these individually specified regions may serve as the "localizer" to improve the alignment of task-fMRI data. We demonstrated that aligning task-fMRI data using the regions derived from resting state fMRI may lead to increased statistical power of task-fMRI analyses. In addition, resting state functional connectivity among these homologous regions is able to capture the idiosyncrasies of subjects and better predict fluid intelligence (gF) than connectivity measures derived from group-level brain atlases. Critically, we showed that not only the connectivity but also the size and position of functional regions are related to human behavior. Collectively, these findings suggest that identifying homologous functional regions across individuals can benefit a wide range of studies in the investigation of connectivity, task activation, and brain-behavior associations.

Empirically-derived response trajectories of intensive residential treatment in obsessive-compulsive disorder: A growth mixture modeling approach

BACKGROUND

This study investigated distinct trajectories of treatment response in a naturalistic intensive/residential treatment (IRT) program for adults with severe obsessive-compulsive disorder (OCD). We hypothesized that: (1) distinct trajectories would emerge and (2) demographic variables, psychiatric comorbidity, OCD symptom subtype, level of insight, previous exposure and response prevention (ERP) treatment, and quality of life, would differentially predict assignment to these trajectories.

METHODS

Participants included 305 individuals with primary OCD admitted for IRT.

RESULTS

Two trajectories emerged over the course of the first eight weeks of treatment, with the vast majority of participants demonstrating treatment response. The first trajectory (96%, n = 292) showed a negative, linear treatment response (a.k.a. "linear responders") and more severe OCD symptoms at admission. The second trajectory (4%, n = 13) had less severe OCD symptoms at admission and did not exhibit a significant overall change in symptoms over the course of treatment. More specifically, this second trajectory or "u-shaped responders" show a non-significant linear response through week four of treatment, followed by slightly increased symptoms in week five. Assignment to these classes was not differentially predicted by hypothesized predictor variables.

LIMITATIONS

Our final model had inconsistent fit indices and small class prevalance of the u-shaped responder group; therefore, model selection was based on both fit indices and substantive meaning.

CONCLUSIONS

This study emprically derived two distinct trajectories of OCD symptom severity over the course of IRT. These findings have the potential to refine IRT for patients with severe OCD, and to potentially guide future investigation into the optimal delivery of ERP treatment for OCD generally.

Neuroscientifically Informed Formulation and Treatment Planning for Patients With Obsessive-Compulsive Disorder: A Review

IMPORTANCE

Obsessive-compulsive disorder (OCD) is a common and often debilitating psychiatric illness. Recent advances in the understanding of the neuroscience of OCD have provided valuable insights that have begun to transform the way we think about the management of this disorder. This educational review provides an integrated neuroscience perspective on formulation and treatment planning for patients with OCD. The article is organized around key neuroscience themes most relevant for OCD.

OBSERVATIONS

An integrated neuroscience formulation of OCD is predicated on a fundamental understanding of phenomenology and symptom dimensions, fear conditioning and extinction, neurochemistry, genetics and animal models, as well as neurocircuitry and neurotherapeutics. Symptom dimensions provide a means to better understand the phenotypic heterogeneity within OCD with an eye toward more personalized treatments. The concept of abnormal fear extinction is central to OCD and to the underlying therapeutic mechanism of exposure and response prevention. A framework for understanding the neurochemistry of OCD focuses on both traditional monoaminergic systems and more recent evidence of glutamatergic and γ-aminobutyric acid-ergic dysfunction. Obsessive-compulsive disorder is highly heritable, and future work is needed to understand the contribution of genes to underlying pathophysiology. A circuit dysregulation framework focuses on cortico-striato-thalamo-cortical circuit dysfunction and the development of neurotherapeutic approaches targeting this circuit. The impact of these concepts on how we think about OCD diagnosis and treatment is discussed. Suggestions for future investigations that have the potential to further enhance the clinical management of OCD are presented.

CONCLUSIONS AND RELEVANCE

These key neuroscience themes collectively inform formulation and treatment planning for patients with OCD. The ultimate goal is to increase crosstalk between clinicians and researchers in an effort to facilitate translation of advances in neuroscience research to improved care for patients with OCD.

Use of an Individual-Level Approach to Identify Cortical Connectivity Biomarkers in Obsessive-Compulsive Disorder

BACKGROUND

Existing functional connectivity studies of obsessive-compulsive disorder (OCD) support a model of circuit dysfunction. However, these group-level observations have failed to yield neuroimaging biomarkers sufficient to serve as a test for the OCD diagnosis, predict current or future symptoms, or predict treatment response, perhaps because these studies failed to account for the substantial intersubject variability in structural and functional brain organization.

METHODS

We used functional regions, localized in each of 41 individual OCD patients, to identify cortical connectivity biomarkers of both global and dimension-specific symptom severity and to detect functional connections that track changes in symptom severity following intensive residential treatment.

RESULTS

Global OCD symptom severity was directly linked to dysconnectivity between large-scale intrinsic brain networks-particularly among the dorsal attention, default, and frontoparietal networks. Changes within a subset of connections among these networks were associated with symptom resolution. Additionally, distinct and nonoverlapping cortical connectivity biomarkers were identified that were significantly associated with the severity of contamination/washing and responsibility for harm/checking symptoms, highlighting the contribution of dissociable neural networks to specific OCD symptom dimensions. By contrast, when we defined functional regions conventionally, using a population-level brain atlas, we could no longer identify connectivity biomarkers of severity or improvement for any of the symptom dimensions.

CONCLUSIONS

Our findings would seem to encourage the use of individual-level approaches to connectivity analyses to better delineate the cortical and subcortical networks underlying symptom severity and improvement at the dimensional level in OCD patients.

Validating an abbreviated version of the Obsessive Beliefs Questionnaire

OBJECTIVES

A shorter version of the Obsessive Beliefs Questionnaire (OBQ-44) is needed to promote the use of this measure in research and increase our understanding of cognitive phenomena maintaining obsessive-compulsive disorder (OCD). Additionally, an abbreviated version of the OBQ-44 would encourage frequent monitoring of dysfunctional beliefs in intensive care settings. This study aimed to validate a nine-item version of the questionnaire (OBQ-9).

METHOD

Participants seeking intensive/residential treatment for OCD (N = 311) completed relevant measures on a weekly basis and at admission and discharge.

RESULTS

A confirmatory factor analysis revealed that the OBQ-9's factor structure replicated the three-factor solution of the OBQ-44. The OBQ-9 demonstrated good psychometric properties and convergent validity and was sensitive to treatment effects. Finally, the OBQ-9 subscales predicted specific OCD dimensions over and above depressive symptoms.

CONCLUSION

The OBQ-9 appears to be a psychometrically sound tool for routine outcome monitoring of dysfunctional beliefs in hospital-based settings.

Acute change in anterior cingulate cortex GABA, but not glutamine/glutamate, mediates antidepressant response to citalopram

Little is known about the acute effects of antidepressant treatments on brain glutamate and gamma-amino-butyric acid (GABA) levels, and their association with clinical response. Using proton magnetic resonance spectroscopy (¹H-MRS) we examined longitudinally the effects of citalopram on glutamine/glutamate ratios and GABA levels in the pregenual anterior cingulate cortex (pgACC) of individuals with major depressive disorder (MDD). We acquired ¹H-MRS scans at baseline and at days 3, 7, and 42 of citalopram treatment in nineteen unmedicated individuals with MDD. Ten age- and sex-matched non-depressed comparison individuals were scanned once. The association between 1) baseline metabolites and 2) change in metabolites from baseline to each time point and clinical response (change in Montgomery-Åsberg Depression Rating Scale (MADRS) score from baseline to day 42) was assessed by longitudinal regression analysis using generalized estimating equations. Contrary to our hypotheses, no significant associations emerged between glutamate metabolites and clinical response; however, greater increases (or smaller decreases) in pgACC GABA levels from baseline to days 3 and 7 of citalopram treatment were significantly associated with clinical response. These findings suggest that an acute change in GABA levels in pgACC predicts, and possibly mediates, later clinical response to citalopram treatment in individuals with MDD.

Validation of the distress tolerance scale-short form in obsessive compulsive disorder

OBJECTIVE

This study aimed to develop and validate the Distress Tolerance Scale-Short Form (DTS-SF), a modification of the original Distress Tolerance Scale, in a severe/complex sample of individuals with obsessive compulsive disorder (OCD). Currently, there are multiple self-report measurements of distress tolerance (DT), highlighting the need for a more refined measure.

METHOD

Participants included 222 individuals with a primary diagnosis of OCD (57% male, average age = 31) seeking intensive/residential treatment. Participants completed surveys at admission, discharge, and each week.

RESULTS

An exploratory factor analysis revealed a one-factor solution representing overall DT ability. The DTS-SF was found to be sensitive to treatment effects. Appropriate associations between the DTS-SF and other measures were also found, with lower DT associated with greater OCD and depression severity and lower reported quality of life.

CONCLUSION

The DTS-SF was found to be a valid and reliable measure with high clinical utility for quickly and accurately measuring DT.

How willing are you? Willingness as a predictor of change during treatment of adults with obsessive-compulsive disorder

OBJECTIVE

Exposure and response prevention (ERP) is an effective treatment for individuals with obsessive-compulsive disorder (OCD), yet a substantial number of individuals with OCD do not fully respond to this intervention. Based on emerging experimental and clinical research on acceptance, this study sought to explore whether willingness to experience unpleasant thoughts, emotions, and bodily sensations during ERP was associated with improved treatment response.

METHODS

Two hundred eighty-eight adults with OCD receiving residential ERP provided self-rated willingness and other exposure-related variables during each daily coached ERP session. Obsessive-compulsive and depressive symptom severity was assessed every week. Multilevel modeling was used to study the impact of willingness on treatment outcome during the first 6 weeks of residential care.

RESULTS

Data indicated that individuals with higher willingness during ERP reported faster symptom reduction during residential treatment, even when controlling for length of stay, psychopharmacological intervention, depression, adherence, and rituals performed during ERP. These results appear to have both statistical and clinical significance.

CONCLUSIONS

Willingness to fully experience unpleasant and unwanted thoughts, emotions, and bodily sensations during exposures appears to be a marker of successful exposure therapy in adults with OCD. Future research should examine how willingness may enhance extinction learning during ERP.

LOWER POSTERIOR CINGULATE CORTEX GLUTATHIONE LEVELS IN OBSESSIVE-COMPULSIVE DISORDER

BACKGROUND

Several lines of evidence support the hypothesis that lower cerebral levels of glutathione (GSH), associated with increased oxidative stress, may contribute to obsessive-compulsive disorder (OCD). However, no studies to date have investigated brain GSH levels in individuals with OCD.

METHODS

Twenty-nine individuals with OCD and 25 age-, sex-, and race-matched comparison individuals without OCD underwent single voxel 2D J-resolved proton magnetic resonance spectroscopy (MRS) to examine GSH levels in the posterior cingulate cortex (PCC). MRS data were analyzed using LCModel and a simulated basis set. Group metabolite differences referenced to total creatine (Cr), as well as relationships between metabolite ratios and symptom severity as measured by the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), were analyzed using linear regression with adjustment for age, sex, and race.

RESULTS

One OCD participant failed to produce usable PCC MRS data. We found significantly lower PCC GSH/Cr in OCD participants compared with non-OCD participants (β = -0.027 [95% CI: -0.049 to -5.9 × 10^-3]; P = 0.014). PCC GSH/Cr was not significantly associated with total Y-BOCS score in the OCD group (β = 5.7 × 10^-4 [95% CI: -4.8 × 10^-3 to 5.9 × 10^-3]; P = 0.83).

CONCLUSIONS

Lower PCC GSH/Cr may be indicative of increased oxidative stress secondary to hypermetabolism in this brain region in OCD. Future MRS studies are warranted to investigate GSH levels in other brain regions that comprise the cortico-striato-thalamo-cortical circuit thought to be abnormal in OCD.

An Examination of Rostral Anterior Cingulate Cortex Function and Neurochemistry in Obsessive-Compulsive Disorder

The anterior cingulate cortex is implicated in the neurobiology of obsessive-compulsive disorder (OCD). However, few studies have examined functional and neurochemical abnormalities specifically in the rostral subdivision of the ACC (rACC) in OCD patients. We used functional magnetic resonance imaging (fMRI) during an emotional counting Stroop task and single-voxel J-resolved proton magnetic resonance spectroscopy ((1)H-MRS) in the rACC to examine the function and neurochemistry of the rACC in individuals with OCD and comparison individuals without OCD. Between-group differences in rACC activation and glutamine/glutamate ratio (Gln/Glu), Glu, and Gln levels, as well as associations between rACC activation, Gln/Glu, Glu, Gln, behavioral, and clinical measures were examined using linear regression. In a sample of 30 participants with OCD and 29 age- and sex-matched participants without OCD, participants with OCD displayed significantly reduced rACC deactivation compared with those without OCD in response to OCD-specific words versus neutral words on the emotional counting Stroop task. However, Gln/Glu, Glu, and Gln in the rACC did not differ between groups nor was there an association between reduced rACC deactivation and Gln/Glu, Glu, or Gln in the OCD group. Taken together, these findings strengthen the evidence for rACC dysfunction in OCD, but weigh against an underlying association with abnormal rACC glutamatergic neurotransmission.

Brain and cognition abnormalities in long-term anabolic-androgenic steroid users

BACKGROUND

Anabolic-androgenic steroid (AAS) use is associated with psychiatric symptoms including increased aggression as well as with cognitive dysfunction. The brain effects of long-term AAS use have not been assessed in humans.

METHODS

This multimodal magnetic resonance imaging study of the brain compared 10 male weightlifters reporting long-term AAS use with 10 age-matched weightlifters reporting no AAS exposure. Participants were administered visuospatial memory tests and underwent neuroimaging. Brain volumetric analyses were performed; resting-state fMRI functional connectivity (rsFC) was evaluated using a region-of-interest analysis focused on the amygdala; and dorsal anterior cingulate cortex (dACC) metabolites were quantified by proton magnetic resonance spectroscopy (MRS).

RESULTS

AAS users had larger right amygdala volumes than nonusers (P=0.002) and reduced rsFC between right amygdala and frontal, striatal, limbic, hippocampal, and visual cortical areas. Left amygdala volumes were slightly larger in AAS users (P=0.061) but few group differences were detected in left amygdala rsFC. AAS users also had lower dACC scyllo-inositol levels (P=0.004) and higher glutamine/glutamate ratios (P=0.028), possibly reflecting increased glutamate turnover. On a visuospatial cognitive task, AAS users performed more poorly than nonusers, with the difference approaching significance (P=0.053).

CONCLUSIONS

Long-term AAS use is associated with right amygdala enlargement and reduced right amygdala rsFC with brain areas involved in cognitive control and spatial memory, which could contribute to the psychiatric effects and cognitive dysfunction associated with AAS use. The MRS abnormalities we detected could reflect enhanced glutamate turnover and increased vulnerability to neurotoxic or neurodegenerative processes, which could contribute to AAS-associated cognitive dysfunction.

REDUCED DISGUST PROPENSITY IS ASSOCIATED WITH IMPROVEMENT IN CONTAMINATION/WASHING SYMPTOMS IN OBSESSIVE-COMPULSIVE DISORDER

OBJECTIVES

Disgust is a well-established phenomenon with known neurobiological correlates. However, it remains unclear how or whether disgust changes with clinical treatment, because few longitudinal studies have tracked the association of disgust vulnerability and clinical symptoms in patient populations.

METHODS

We assessed disgust propensity and symptoms of obsessive-compulsive disorder (OCD) in 134 patients receiving intensive residential treatment for OCD. Using linear regression with adjustment for age, sex, and depression severity, we tested the association between change in disgust propensity and change in OCD symptoms from admission to discharge.

RESULTS

Change in disgust propensity was significantly associated with improvement in contamination/washing symptoms (β = 0.25 [95% confidence interval: 0.11-0.39]; P = .001). No significant association was found between change in disgust propensity and change in other OCD symptom dimensions.

CONCLUSIONS

In patients with OCD undergoing intensive residential treatment, disgust propensity appears to improve in parallel with contamination/washing symptoms.

Intensive residential treatment for severe obsessive-compulsive disorder: characterizing treatment course and predictors of response

BACKGROUND

Intensive residential treatment (IRT) is effective for severe, treatment-resistant obsessive-compulsive disorder (OCD). We sought to characterize predictors and course of response to IRT.

METHODS

Admission, monthly, and discharge data were collected on individuals receiving IRT. We examined the association between baseline characteristics and percent change in OCD symptoms as measured by the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) using linear regression. We compared baseline characteristics of IRT responders (≥35% reduction in Y-BOCS) versus non-responders, and of patients who did versus those who did not achieve wellness (Y-BOCS ≤ 12) using non-parametric tests. To examine the course of OCD severity over time, we used linear mixed-effects models with randomly varying intercepts and slopes.

RESULTS

We evaluated 281 individuals admitted to an IRT program. Greater baseline Y-BOCS scores were associated with a significantly greater percent reduction in Y-BOCS scores (β = -1.49 ([95% confidence interval: -2.06 to -0.93]; P < .001)). IRT responders showed significantly greater baseline Y-BOCS scores than non-responders (mean (SD) 28 (5.2) vs. 25.6 (5.8); P = .003) and lower past-year alcohol use scores than non-responders (1.4 (1.9) vs. 2.1 (2.2); P = .01). Participants who achieved wellness displayed lower hoarding factor scores than those who did not (5 (4.6) vs. 9.53 (6.3); P = .03). OCD symptoms declined rapidly over the first month but more slowly over the remaining two months.

CONCLUSIONS

Higher baseline OCD severity, lower past-year alcohol use, and fewer hoarding symptoms predicted better response to IRT. IRT yielded an initial rapid reduction in OCD symptoms, followed by a slower decline after the first month.

Performance-enhancing drugs on the web: a growing public-health issue

BACKGROUND AND OBJECTIVES

Today's Internet provides extensive "underground" guidelines for obtaining and using illicit substances, including especially anabolic-androgenic steroids (AAS) and other appearance- and performance-enhancing drugs (APEDs). We attempted to qualitatively characterize APED-related Internet sites.

METHODS

We used relevant Internet search terms (eg, "steroids bodybuilding" and "buy steroids online") to assess (i) the numbers of site visitors; (ii) offers of drugs for sale; and (iii) the quality of online medical information. We also chose the examples of (iv) "site-enhancing oils" and (v) "cattle implants" to illustrate the volume of available Internet information as compared with that in the medical literature.

RESULTS

We found thousands of sites involving AAS and other APEDs. Most sites presented an unabashedly pro-drug position, often openly questioning the qualifications and motivations of mainstream medical practitioners. Offers of AAS and other APEDs for sale, together with medical advice of varying legitimacy, was widespread across sites. Importantly, many sites provided detailed guidelines for exotic forms of APED use, some likely associated with serious health risks, which are probably unknown to most practicing clinicians.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

It seems important for practitioners to be aware of the extent of this "underground literature," which may strongly influence their patients' decisions about use and abuse of APEDs.

Mitochondrial modulators for bipolar disorder: a pathophysiologically informed paradigm for new drug development

OBJECTIVES

Bipolar patients frequently relapse within 12 months of their previous mood episode, even in the context of adequate treatment, suggesting that better continuation and maintenance treatments are needed. Based on recent research of the pathophysiology of bipolar disorder, we review the evidence for mitochondrial dysregulation and selected mitochondrial modulators (MM) as potential treatments.

METHODS

We reviewed the literature about mitochondrial dysfunction and potential MMs worthy of study that could improve the course of bipolar disorder, reduce subsyndromal symptoms, and prevent subsequent mood episodes.

RESULTS

MM treatment targets mitochondrial dysfunction, oxidative stress, altered brain energy metabolism and the dysregulation of multiple mitochondrial genes in patients with bipolar disorder. Several tolerable and readily available candidates include N-acetyl-cysteine (NAC), acetyl-L-carnitine (ALCAR), S-adenosylmethionine (SAMe), coenzyme Q(10) (CoQ10), alpha-lipoic acid (ALA), creatine monohydrate (CM), and melatonin. The specific metabolic pathways by which these MMs may improve the symptoms of bipolar disorder are discussed and combinations of selected MMs could be of interest as well.

CONCLUSIONS

Convergent data implicate mitochondrial dysfunction as an important component of the pathophysiology of bipolar disorder. Clinical trials of individual MMs as well as combinations are warranted.

A critical review of magnetic resonance spectroscopy studies of obsessive-compulsive disorder

Functional neuroimaging studies have converged to suggest that cortico-striatal-thalamo-cortical (CSTC) circuit dysfunction is a core pathophysiologic feature of obsessive-compulsive disorder (OCD). Now, complementary approaches examining regional neurochemistry are beginning to yield additional insights with regard to the neurobiology of aberrant CSTC circuitry in OCD. In particular, proton magnetic resonance spectroscopy, which allows for the in vivo quantification of various neurochemicals in the CSTC circuit and other brain regions, has recently been used extensively in studies of OCD patients. In this review, we summarize the diverse and often seemingly inconsistent findings of these studies, consider methodological factors that might help to explain these inconsistencies, and discuss several convergent findings that tentatively seem to be emerging. We conclude with suggestions for possible future proton magnetic resonance spectroscopy studies in OCD.

Testosterone gel replacement improves sexual function in depressed men taking serotonergic antidepressants: a randomized, placebo-controlled clinical trial

Testosterone replacement is the most effective treatment for sexual dysfunction in hypogonadal men. Comorbid depression and antidepressant side effects may reduce its influence. The authors conducted a 6-week, double-blind, placebo-controlled clinical trial of testosterone gel versus placebo gel in men with major depressive disorder who were currently taking a serotonergic antidepressant and exhibited low or low-normal testosterone level. A total of 100 men were enrolled at 2 study sites (Boston, Massachusetts, USA, and Tel Aviv, Israel). The effects of testosterone augmentation on sexual functioning were determined using domain scores on the International Index of Erectile Function (IIEF). Complete pre- and posttrial IIEF data were available for 63 subjects. Men randomized to testosterone (n = 31) and placebo (n = 32) were similar in age, baseline testosterone levels, and baseline IIEF scores. At study termination, men randomized to placebo showed virtually no change from baseline in mean (95% CI) IIEF score (-0.7 [-6.5, 5.2]), whereas those receiving testosterone exhibited a substantial increase (15.8 [8.5, 23.1]). The estimated mean difference between groups was 16.8 [7.5, 26.1]; p = .001 by linear regression with adjustment for age and study site. There were also significant between-group differences in each of the 5 IIEF subscales, as well as on the single question involving ejaculatory ability (p ≤ .03 in all cases). Effect sizes in these comparisons remained little changed, and generally remained statistically significant, when we further adjusted for change in depression scores on the Montgomery Asberg Depression Rating Scale. It is notable that the subgroup of men with the highest baseline testosterone levels showed virtually the same improvement as those with lower levels, suggesting that the observed improvement was unlikely to be due simply to correction of hypogonadism alone. In depressed men with low or low-normal testosterone levels who continued to take serotonergic antidepressants, treatment with exogenous testosterone was associated with a significant improvement in sexual function, particularly including ejaculatory ability.

Human growth hormone abuse in male weightlifters

In a study of performance-enhancing substance use among 231 experienced young male weightlifters, we found that 27 (12%) reported illicit use of human growth hormone (HGH) or its bioactive derivative, insulin-like growth factor-1. All of these 27 men also reported use of anabolic-androgenic steroids (AAS) and 22 (81%) met criteria for current or past AAS dependence. Fifteen (56%) also reported current or past dependence on opioids, cocaine, and/or ecstasy. These findings suggest that among young male weightlifters, illicit HGH use has become a common form of substance abuse, frequently associated with both AAS dependence and classical substance dependence. 

Rapid enhancement of glutamatergic neurotransmission in bipolar depression following treatment with riluzole

Glutamatergic abnormalities may underlie bipolar disorder (BD). The glutamate-modulating drug riluzole may be efficacious in bipolar depression, but few in vivo studies have examined its effect on glutamatergic neurotransmission. We conducted an exploratory study of the effect of riluzole on brain glutamine/glutamate (Gln/Glu) ratios and levels of N-acetylaspartate (NAA). We administered open-label riluzole 100-200 mg daily for 6 weeks to 14 patients with bipolar depression and obtained imaging data from 8-cm(3) voxels in the anterior cingulate cortex (ACC) and parieto-occipital cortex (POC) at baseline, day 2, and week 6 of treatment, using two-dimensional J-resolved proton magnetic resonance spectroscopy at 4 T. Imaging data were analyzed using the spectral-fitting package, LCModel; statistical analysis used random effects mixed models. Riluzole significantly reduced Hamilton Depression Rating Scale (HAM-D) scores (d=3.4; p<0.001). Gln/Glu ratios increased significantly by day 2 of riluzole treatment (Cohen's d=1.2; p=0.023). NAA levels increased significantly from baseline to week 6 (d=1.2; p=0.035). Reduction in HAM-D scores was positively associated with increases in NAA from baseline to week 6 in the ACC (d=1.4; p=0.053), but was negatively associated in the POC (d=9.6; p<0.001). Riluzole seems to rapidly increase Gln/Glu ratios-suggesting increased glutamate-glutamine cycling, which may subsequently enhance neuronal plasticity and reduce depressive symptoms. Further investigation of the Gln/Glu ratio as a possible early biomarker of response to glutamate-modulating therapies is warranted.

Duloxetine in the treatment of irritable bowel syndrome: an open-label pilot study

OBJECTIVE

To assess the efficacy of duloxetine for irritable bowel syndrome (IBS).

METHODS

We conducted an open-label 12-week trial of duloxetine 60 mg daily in 15 patients with IBS without concurrent major depressive disorder. The primary outcome measure was average abdominal pain. Secondary measures included IBS symptoms, Clinical Global Impression-Severity, Hamilton Anxiety Rating Scale, IBS Quality-of-Life Scale, and Sheehan Disability Scale. We analyzed changes using random regression and one-sample t-tests.

RESULTS

Fourteen patients completed at least one post-baseline evaluation; eight completed the study. Duloxetine was associated with significant improvement (p < 0.05) in pain, severity of illness, quality of life, loose stool, work and family disability, and anxiety. However, duloxetine did not improve hard stool. Although we found no evidence of serious duloxetine toxicity, seven participants withdrew over the course of the study because of adverse drug events.

CONCLUSIONS

In this small, open-label study, duloxetine appeared to be effective for many features of IBS, but its adverse effects, most notably constipation, limited its use. Since our study excluded individuals with concurrent major depression, it appears that duloxetine may benefit IBS independently of its antidepressant effects. These encouraging but preliminary open-label findings support further investigation of duloxetine treatment in placebo-controlled trials of IBS.

Memantine in the treatment of binge eating disorder: an open-label, prospective trial

OBJECTIVE

To assess preliminarily the efficacy of memantine in binge eating disorder.

METHOD

This was an open-label, 12-week, flexible-dose (5-20 mg/day) trial of memantine in binge eating disorder. The primary outcome was frequency of binge days. Secondary outcomes included frequency of binge episodes, body-mass index (BMI), weight, Clinical Global Impressions Severity (CGI-S), Three Factor Eating Questionnaire (TFEQ), Montgomery-Asberg Depression Rating Scale (MADRS), Hamilton Anxiety Rating Scale (HAM-A), and Sheehan Disability Scale (SDS). Longitudinal random regression analysis was performed for frequency of binge days and episodes, BMI, weight, and CGI-S; analysis of baseline to endpoint change was performed for all outcomes.

RESULTS

Sixteen individuals received memantine; 15 completed at least one postbaseline evaluation, 9 completed the study. Mean dose at endpoint was 18.3 mg/day. Memantine was associated with significant reductions in frequency of binge days and episodes, severity of illness (p < .001 for both analyses), disinhibition on the TFEQ (p = .015), and disability on the SDS (p < .05 for three subscales). There was no significant change in BMI, weight, MADRS, HAM-A, and TFEQ cognitive restraint and hunger.

CONCLUSION

In this open-label trial, memantine was well tolerated and effective in reducing binge eating, severity of illness, and disability, but had little effect on BMI and weight.