Neuroimaging of psychotherapy for obsessive-compulsive disorder: A systematic review

Neurobiology of Obsessive-Compulsive Disorder from Genes to Circuits: Insights from Animal Models

Obsessive-compulsive disorder (OCD) is a chronic, severe psychiatric disorder that has been ranked by the World Health Organization as one of the leading causes of illness-related disability, and first-line interventions are limited in efficacy and have side-effect issues. However, the exact pathophysiology underlying this complex, heterogeneous disorder remains unknown. This scenario is now rapidly changing due to the advancement of powerful technologies that can be used to verify the function of the specific gene and dissect the neural circuits underlying the neurobiology of OCD in rodents. Genetic and circuit-specific manipulation in rodents has provided important insights into the neurobiology of OCD by identifying the molecular, cellular, and circuit events that induce OCD-like behaviors. This review will highlight recent progress specifically toward classic genetic animal models and advanced neural circuit findings, which provide theoretical evidence for targeted intervention on specific molecular, cellular, and neural circuit events.

Effects of cognitive behavioural therapy and exposure-response prevention on brain activation in obsessive-compulsive disorder patients: systematic review and meta-analysis

Current psychotherapeutic treatments for OCD, while effective, have complex outcomes with mixed efficacy. Previous research has observed baseline brain activation patterns in OCD patients, elucidating some of the implications of this disorder. Observing the effects of evidence-based psychotherapeutics for OCD on brain activation (through MRI) may provide a more comprehensive outline of pathology. This systematic review and meta-analysis evaluated the effects of cognitive behavioural therapy (CBT) with exposure-response prevention (ERP) on brain activation in OCD patients. Academic databases were systematically searched, and the outcomes evaluated included changes in brain activation and symptom severity between baseline and post-treatment. Patients (n = 193) had confirmed OCD diagnosis and underwent protocolized CBT with ERP programs delivered by trained therapists. Participants in the CBT with ERP programs demonstrated significant improvements in symptom severity (Cohen's d = - 1.91). In general, CBT with ERP resulted in decreased activation post-treatment in the frontal (Cohen's d = 0.40), parietal (Cohen's d = 0.79), temporal (Cohen's d = 1.02), and occipital lobe (Cohen's d = 0.76), and cerebellum (Cohen's d = - 0.78). The findings support CBT with ERP's ability to improve brain activation abnormalities in OCD patients. By identifying regions that improved activation levels, psychotherapy programs may benefit from the addition of function-specific features that could improve treatment outcomes.

Neuronal correlates of intensification and acceptance of symptoms during exposure therapy in patients with obsessive-compulsive disorder

Introduction

Cognitive behaviour therapy with exposure and response prevention is efficient in treating patients with obsessive-compulsive disorder (OCD). Nevertheless, it would be helpful for many patients to complement the therapeutic treatment with acceptance strategies to further increase the therapeutic benefit. The aim of the present study was to examine neurobiological responses to acceptance and intensification strategies during symptom provocation alongside the psychotherapeutic process.

Method

A total of 23 patients diagnosed with OCD (subtype: washing/contamination fear) was instructed to utilise either an acceptance strategy (ACS) or an intensification strategy (INS) to cope with their emotional and cognitive reactions to personalised symptom-triggering and neutral pictures. Fourteen patients participated twice: at the beginning [T1] and at the end [T2] of an inpatient multimodal treatment including cognitive behaviour therapy with response prevention to assess functional variations.

Results

For the contrast of T1 and T2, ACS showed increased brain activity in the left inferior frontal gyrus (IFG), left caudate body, and posterior cingulate gyrus (PCC). They also showed decreased activity in the left anterior insula. INS showed decreased activation in right lingual gyrus and right caudate body. At T2, ACS showed increased activation compared to INS in the left cerebrum: IFG, caudate nucleus, middle and superior temporal gyrus, and PCC/cuneus. For the comparison of T1 and T2, the ACS revealed increased brain activity in the left IFG, left caudate body, and right inferior parietal lobe. It showed decreased activity in the left anterior insula. The INS revealed decreased activity in right lingual gyrus and right caudate body.The psychometric questionnaires suggested that patients were able to reduce obsession, compulsion, and depression symptoms. Furthermore, patients rated the ACS as more useful for themselves compared with the INS.

Conclusion

The increased left IFG activity using ACS (T1 vs. T2) could be interpreted as a better inhibitory top-down process, while the increased PCC response might be due to a better reappraisal strategy after therapy. ACS seems to mobilise neuronal activations under therapy, especially in the left hemisphere. Both strategies showed reductions in emotional networks as a neuronal correlate of therapy success. Overall, ACS may be more efficient than INS, as rated by the patients and as in accordance with neurobiological findings.

Acceptance and commitment therapy as an add-on treatment for the management of patients with obsessive-compulsive disorder

Background

Obsessive compulsive disorder (OCD) is a chronic and long-lasting illness affecting approximately 2% of the population. Up to 40%-60% of patients with OCD do not have satisfactory outcomes, thereby leading to disability in performing daily routine activities. Acceptance and commitment therapy (ACT) provides a substitute for old-fashioned psychotherapies, as it involves the client directly experiencing the problematic emotion, that is, anxiety and obsessions in the case of OCD.

Aim

To observe the effect of ACT on patients with OCD and compare its effect on obsessive compulsive symptoms, thought control, thought and action fusion, acceptance and action, and depression.

Materials and Methods

A total of 62 patients diagnosed with OCD as per Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) in the age range between 18 and 60 years, having duration of illness less than two years, both male and female, literate and illiterate, hailing from rural and urban background, were included in the study. For pre- and post-assessment Yale-Brown Obsessive and Compulsive Scale (Y-BOCS), Hamilton Depression Rating Scale (HDRS), acceptance and commitment questionnaire, thought control questionnaire, and thought and action fusion questionnaire were used in this study, and ACT was used for management of OCD.

Results

There is a significant difference between the groups treated with ACT and those treated as usual, on every domain of thought control questionnaire (TCQ) -- distraction (t = 9.07), social control (t = 11.13), worry (t = 11.93), punishment (t = 16.78), and re-appraisal (t = 16.47). Significance is also seen in the thought and action fusion in the moral domain (t = 16.22), the likelihood domain (t = 16.49), and others (t = 9.23). On Y-BOCS, HDRS, and acceptance and action questionnaire (AAQ) both groups show a significant difference between each other.

Conclusion

The findings of the present study indicate that ACT is a productive method for patients with OCD as it encourages the patient to accept and integrate their lived experiences, challenges effective responses, and recognizes and eliminates the controlling dimensions.

Using electronically delivered therapy and brain imaging to understand OCD pathology: A pilot feasibility study

Background

Obsessive–compulsive disorder (OCD) is a debilitating mental health disorder with current psychotherapeutic treatments, while somewhat effective, yielding low accessibility and scalability. A lack of knowledge regarding the neural pathology of OCD may be hindering the development of innovative treatments. Previous research has observed baseline brain activation patterns in OCD patients, elucidating some understanding of the implications. However, by using neuroimaging to observe the effects of treatment on brain activation, a more complete picture of OCD can be drawn. Currently, the gold standard treatment is cognitive behavioral therapy (CBT). However, CBT is often inaccessible, time-consuming, and costly. Fortunately, it can be effectively delivered electronically (e-CBT).

Objectives

This pilot study implemented an e-CBT program for OCD and observed its effects on cortical activation levels during a symptom provocation task. It was hypothesized that abnormal activations could be attenuated following treatment.

Methods

OCD patients completed a 16-week e-CBT program administered through an online platform, mirroring in-person content. Treatment efficacy was evaluated using behavioral questionnaires and neuroimaging. Activation levels were assessed at the resting state and during the symptom provocation task.

Results

In this pilot, seven participants completed the program, with significant improvements (p < 0.05) observed between baseline and post-treatment for symptom severity and levels of functioning. No statistically significant (p = 0.07) improvement was observed in the quality of life. Participants had mostly positive qualitative feedback, citing accessibility benefits, comprehensive formatting, and relatable content. No significant changes in cortical activation were observed between baseline and post-treatment.

Conclusion

This project sheds light on the application of e-CBT as a tool to evaluate the effects of treatment on cortical activation, setting the stage for a larger-scale study. The program showed great promise in feasibility and effectiveness. While there were no significant findings regarding changes in cortical activation, the trends were in agreeance with previous literature, suggesting future work could provide insight into whether e-CBT offers comparable cortical effects to in-person psychotherapy. Applying a greater knowledge of the neural mechanisms of action in OCD can help develop novel treatment plans in the future.

Unhealthy mind in a healthy body: A criticism to eliminativism in psychopathology

In this article we criticize the thesis "The diseases we treat are diseases of the brain". A first criticism is against the eliminativist perspective and in favor of a perspective that is still reductionist but emergentist and functionalist. In a second part, we try to answer the question "under which conditions can we consider this statement legitimate?". We argue that only those mental disorders whose neural substrate has clearly neuropathological characteristics, i.e., anomalies with respect to the laws of good neural functioning, can be considered "brain diseases." We propose that it is not sufficient to observe a simple difference between the brains of people with psychopathology, that is, with anomalies with respect to the laws of good psychological functioning, and that of people without psychopathology. Indeed, we believe it is a categorical error to postulate a neuropathology starting from a psychopathology. Finally, we summarize some research that shows how purely psychological interventions can reduce or eliminate the differences between the brains of people with or psychopathology and those of people without.

Boosting psychological change: Combining non-invasive brain stimulation with psychotherapy

Mental health disorders and substance use disorders are a leading cause of morbidity and mortality worldwide, and one of the most important challenges for public health systems. While evidence-based psychotherapy is generally pursued to address mental health challenges, psychological change is often hampered by non-adherence to treatments, relapses, and practical barriers (e.g., time, cost). In recent decades, Non-invasive brain stimulation (NIBS) techniques have emerged as promising tools to directly target dysfunctional neural circuitry and promote long-lasting plastic changes. While the therapeutic efficacy of NIBS protocols for mental illnesses has been established, neuromodulatory interventions might also be employed to support the processes activated by psychotherapy. Indeed, combining psychotherapy with NIBS might help tailor the treatment to the patient's unique characteristics and therapeutic goal, and would allow more direct control of the neuronal changes induced by therapy. Herein, we overview emerging evidence on the use of NIBS to enhance the psychotherapeutic effect, while highlighting the next steps in advancing clinical and research methods toward personalized intervention approaches.

Imbalance between the caudate and putamen connectivity in obsessive-compulsive disorder

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The imbalance between the caudate and putamen connectivity in OCD patient arises from the abnormal connection of caudate.

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The abnormal caudate connectivity mainly results from the outward extension of cortico-striato-thalamo-cortical loop.

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The caudate connectivity of OCD patients is negatively associated with their task-switch performance.

Background

Compulsive behaviors in obsessive–compulsive disorder (OCD) have been suggested to result from an imbalance in cortico-striatal connectivity. However, the nature of this impairment, the relative involvement of different striatal areas, their imbalance in genetically related but unimpaired individuals, and their relationship with cognitive dysfunction in OCD patients, remain unknown.

Methods

In the current study, striatal (i.e., caudate and putamen) whole-brain connectivity was computed in a sample of OCD patients (OCD, n = 62), unaffected first-degree relatives (UFDR, n = 53) and healthy controls (HC, n = 73) by ROI-based resting-state functional magnetic resonance imaging (rs-fMRI). A behavioral task switch paradigm outside of the scanner was also performed to measure cognitive flexibility in OCD patients.

Results

There were significantly increased strengths (Z-transformed Pearson correlation coefficient) in caudate connectivity in OCD patients. A significant correlation between the two types of connectivity strengths in the relevant regions was observed only in the OCD patient group. Furthermore, the caudate connectivity of patients was negatively associated with their task-switch performance.

Conclusions

The imbalance between the caudate and putamen connectivity, arising from the abnormal increase of caudate activity, may serve as a clinical characteristic for obsessive–compulsive disorder.

Symptom provocation in obsessive-compulsive disorder: A voxel-based meta-analysis and meta-analytic connectivity modeling

BACKGROUND

Obsessive-compulsive disorder (OCD) is a heterogeneous psychiatric illness with a complex array of symptoms and potentially distinct neural underpinnings. We employed meta-analysis and connectivity modeling of symptom dimensions to delineate the circuit mechanisms of OCD.

METHODS

With the activation likelihood estimation (ALE) algorithm we performed meta-analysis of whole-brain functional magnetic resonance imaging (fMRI) studies of symptom provocation. We contrasted all OCD patients and controls in a primary analysis and divided the studies according to clinical symptoms in secondary meta-analyses. Finally, we employed meta-analytic connectivity modeling analyses (MACMs) to examine co-activation patterns of the brain regions revealed in the primary meta-analysis.

RESULTS

A total of 14 experiments from 12 eligible studies with a total of 238 OCD patients (124 men) and 219 healthy controls (120 men) were included in the primary analysis. OCD patients showed higher activation in the right caudate body/putamen/insula and lower activation in the left orbitofrontal cortex (OFC), left inferior frontal gyrus (IFG), left caudate body/middle cingulate cortex (MCC), right middle temporal gyrus (MTG), middle occipital gyrus (MOG) and right lateral occipital gyrus (LOG). MACMs revealed significant co-activation between left IFG and left caudate body/MCC, left MOG and right LOG, right LOG and MTG. In the secondary meta-analyses, the washing subgroup showed higher activation in the right OFC, bilateral ACC, left MOG and right caudate body.

CONCLUSION

OCD patients showed elevated dorsal striatal activation during symptom provocation. In contrast, the washing subgroup engaged higher activation in frontal, temporal and posterior cortical structures as well as right caudate body. Broadly consistent with the proposition of cortico-striatal-thalamic-cortical circuit dysfunction, these findings highlight potentially distinct neural circuits that may underlie the symptoms and potentially etiological subtypes of OCD.

Diffusion Tensor Imaging Before and 3 Months After Concentrated Exposure Response Prevention in Obsessive-Compulsive Disorder

Background: Subtle differences in white matter microstructure have been found in obsessive-compulsive disorder (OCD) compared to controls using diffusion tensor imaging (DTI), but it is unclear if and how this change after treatment. The primary aim of this pre-registered study was to investigate white matter integrity between OCD patients and controls and changes after concentrated exposure and response prevention (ERP). Methods: Fractional anisotropy (FA), radial diffusivity (RD), axial diffusivity (AD) and mean diffusivity (MD) were estimated using FMRIB Software Library (FSL). The images were registered to a study-specific template using a longitudinal pipeline based on full tensor information in DTI-TK. Voxel-based analysis was performed using tract-based spatial statistics (TBSS). Using SPSS, we compared the integrity in three bilateral regions of interest (ROI), the sagittal stratum, posterior thalamic radiation and cingulum, in 32 OCD patients and 30 matched healthy controls at baseline. Patients received a four-day concentrated ERP format. We investigated longitudinal changes in 26 OCD patients and 22 healthy controls at 3months follow-up using repeated-measures ANOVA. Exploratory t-tests were conducted for AD and MD. Secondary hypothesis used linear regression to investigate if baseline FA predict treatment outcome 3 months later, and if patients with illness onset before 18 years of age would show lower FA in sagittal stratum. Finally, we performed sensitivity analysis on medication and comorbidity influences on FA. Results: Three months after treatment, 77% of the patients were in remission. Contrary to our hypotheses, we did not find any significant differences in FA, RD, AD or MD between the groups before treatment, nor significant group by time effects in any of the ROI. None of the baseline FA measures significantly predicted treatment outcome. Illness onset before 18 years of age did not significantly predict FA in the sagittal stratum. Adjusting for medication or comorbid anxiety or mood disorder did not influence the results. Conclusions: Although concentrated ERP in OCD lead to high remission, we did not find significant long-term changes by DTI. Future studies will benefit from using larger sample sizes and multi-shell diffusion-weighted imaging when investigating white matter microstructure in OCD and underlying neurobiological mechanisms of treatment.

Cognitive Control in Pediatric Obsessive-Compulsive and Anxiety Disorders: Brain-Behavioral Targets for Early Intervention

The DSM provides distinct criteria for obsessive-compulsive disorder (OCD) and various types of anxiety disorders, but phenomenological overlap, high rates of comorbidity, and early onset suggest common underlying mechanisms. This notion is further supported by use of the same treatments-cognitive behavioral therapy and serotonin reuptake inhibitor medication-for managing both OCD and non-OCD anxiety disorders in clinical settings. While early intervention with these gold standard treatments is recommended for pediatric OCD and anxiety disorders, young patients often remain symptomatic even after treatment. To guide the development of novel, mechanistically targeted treatments to better resolve OCD and anxiety symptoms, the identification of neural circuits underlying psychological constructs with relevance across disorders has been recommended. One construct that may be relevant for understanding pediatric OCD and anxiety disorders is cognitive control, given the difficulty that young patients experience in dismissing obsessions, compulsions, and worry despite recognition that these symptoms are excessive and unreasonable. In this review, we examine findings from a growing body of literature implicating brain-behavioral markers of cognitive control in pediatric OCD and anxiety disorders, including before and after treatment. We conclude by suggesting that interventions designed to enhance the functioning of the task control circuits underlying cognitive control may facilitate brain maturation to help affected youth overcome symptoms.

Neural correlates of cognitive behavioral therapy response in youth with negative valence disorders: A systematic review of the literature

BACKGROUND

Cognitive-behavioral therapy (CBT) is the gold-standard psychotherapeutic treatment for pediatric negative valence disorders. However, some youths do not respond optimally to treatment, which may be due to variations in neural functioning.

METHODS

We systematically reviewed functional magnetic resonance imaging studies in youths with negative valence disorders to identify pre- and post-treatment neural correlates of CBT response.

RESULTS

A total of 21 studies were identified, of overall weak to moderate quality. The most consistent findings across negative valence disorders consisted of associations of treatment response with pre- and post-treatment task-based activation and/or functional connectivity within and between the prefrontal cortex, the medial temporal lobe, and other limbic regions. Associations of CBT response with baseline and/or post-treatment activity in the striatum, precentral and postcentral gyri, medial and posterior cingulate cortices, and parietal cortex, connectivity within and between the default-mode, cognitive control, salience, and frontoparietal networks, and metrics of large-scale brain network organization, were also reported, although less consistently.

LIMITATIONS

The poor quality and limited number of studies and the important heterogeneity of study designs and results considerably limit the conclusions that can be drawn from this literature.

CONCLUSIONS

Despite these limitations, these findings provide preliminary evidence suggesting youths presenting certain patterns of brain function may respond better to CBT, whereas others may benefit from alternative or augmented forms of treatment.

The effects of cognitive behavioral therapy on the whole brain structural connectome in unmedicated patients with obsessive-compulsive disorder

Cognitive behavioral therapy (CBT) is considered a first-line treatment for patients with obsessive-compulsive disorder (OCD), and it possesses advantages over pharmacological treatments in stronger tolerance to distress, lower rates of drop out and relapse, and no physical "side-effects". Previous studies have reported CBT-related alterations in focal brain regions and connections. However, the effects of CBT on whole-brain structural networks have not yet been elucidated. Here, we collected diffusion MRI data from 34 unmedicated OCD patients before and after 12 weeks of CBT. Fifty healthy controls (HCs) were also scanned twice at matched intervals. We constructed individual brain white matter connectome and performed a graph-theoretical network analysis to investigate the effects of CBT on whole-brain structural topology. We observed significant group-by-time interactions on the global network clustering coefficient and the nodal clustering of the left lingual gyrus, the left middle temporal gyrus, the left precuneus, and the left fusiform gyrus of 26 CBT responders in OCD patients. Further analysis revealed that these CBT responders showed prominently higher global and nodal clustering compared to HCs at baseline and reduced to normal levels after CBT. Such significant changes in the nodal clustering of the left lingual gyrus were also found in 8 CBT non-responders. The pre-to-post decreases in nodal clustering of the left lingual gyrus and the left fusiform gyrus positively correlated with the improvements in obsessive-compulsive symptoms in the CBT-responding patients. These findings indicated that the network segregation of the whole-brain white matter network in OCD patients was abnormally higher and might recover to normal after CBT, which provides mechanistic insights into the CBT response in OCD and potential imaging biomarkers for clinical practice.

A Systematic Review of Behavioral, Physiological, and Neurobiological Cognitive Regulation Alterations in Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is characterized by cognitive regulation deficits. However, the current literature has focused on executive functioning and emotional response impairments in this disorder. Herein, we conducted a systematic review of studies assessing the behavioral, physiological, and neurobiological alterations in cognitive regulation in obsessive-compulsive patients using the PubMed database. Most of the studies included explored behavioral (distress, arousal, and frequency of intrusive thoughts) and neurobiological measures (brain activity and functional connectivity) using affective cognitive regulation paradigms. Our results pointed to the advantageous use of reappraisal and acceptance strategies in contrast to suppression to reduce distress and frequency of intrusive thoughts. Moreover, we observed alterations in frontoparietal network activity during cognitive regulation. Our conclusions are limited by the inclusion of underpowered studies with treated patients. Nonetheless, our findings support the OCD impairments in cognitive regulation of emotion and might help to improve current guidelines for cognitive therapy.

Stable inhibition-related inferior frontal hypoactivation and fronto-limbic hyperconnectivity in obsessive-compulsive disorder after concentrated exposure therapy

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Less IFG activation and more fronto-limbic connectivity was found in OCD.

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IFG hypoactivation and fronto-limbic hyperconnectivity persisted after exposure therapy.

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Activation and connectivity before treatment did not predict treatment outcome.

Response inhibition has previously been suggested as an endophenotype for obsessive–compulsive disorder (OCD), evidenced by studies showing worse task performance, and altered task-related activation and connectivity. However, it’s unclear if these measures change following treatment. In this study, 31 OCD patients and 28 healthy controls performed a stop signal task during 3 T functional magnetic resonance imaging before treatment, while 24 OCD patients and 17 healthy controls were rescanned one week and three months after concentrated exposure and response prevention over four consecutive days using Bergen 4-Day Format. To study changes over time we performed a longitudinal analysis on stop signal reaction time and task-related activation and amygdala connectivity during successful and failed inhibition. Results showed that there was no group difference in task performance. Before treatment, OCD patients compared to controls showed less inhibition-related activation in the right inferior frontal gyrus, and increased functional connectivity between the right amygdala and the right inferior frontal gyrus and pre-supplementary motor area. During error-processing, OCD patients versus controls showed less activation in the pre-SMA before treatment. These group differences did not change after treatment. Pre-treatment task performance, brain activation, and connectivity were unrelated to the degree of symptom improvement after treatment. In conclusion, inferior frontal gyrus hypoactivation and increased fronto-limbic connectivity are likely trait markers of OCD that remain after effective exposure therapy.

Obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a highly prevalent and chronic condition that is associated with substantial global disability. OCD is the key example of the 'obsessive-compulsive and related disorders', a group of conditions which are now classified together in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and the International Classification of Diseases, 11th Revision, and which are often underdiagnosed and undertreated. In addition, OCD is an important example of a neuropsychiatric disorder in which rigorous research on phenomenology, psychobiology, pharmacotherapy and psychotherapy has contributed to better recognition, assessment and outcomes. Although OCD is a relatively homogenous disorder with similar symptom dimensions globally, individualized assessment of symptoms, the degree of insight, and the extent of comorbidity is needed. Several neurobiological mechanisms underlying OCD have been identified, including specific brain circuits that underpin OCD. In addition, laboratory models have demonstrated how cellular and molecular dysfunction underpins repetitive stereotyped behaviours, and the genetic architecture of OCD is increasingly understood. Effective treatments for OCD include serotonin reuptake inhibitors and cognitive-behavioural therapy, and neurosurgery for those with intractable symptoms. Integration of global mental health and translational neuroscience approaches could further advance knowledge on OCD and improve clinical outcomes.

Emotion Regulation in Obsessive-Compulsive Disorder, Unaffected Siblings, and Unrelated Healthy Control Participants

BACKGROUND

Functional neuroimaging endophenotypes of obsessive-compulsive disorder (OCD) have been suggested during executive tasks. The purpose of this study was to investigate whether behavioral and neural responses during emotion processing and regulation also represent an endophenotype of OCD.

METHODS

Forty-three unmedicated adult OCD patients, 19 of their unaffected siblings, and 38 healthy control participants underwent 3T functional magnetic resonance imaging during an emotion regulation task including neutral, fear-inducing, and OCD-related visual stimuli. Stimuli were processed during natural appraisal and during cognitive reappraisal, and distress ratings were collected after each picture. We performed between-group comparisons on task behavior and brain activation in regions of interest during emotion provocation and regulation.

RESULTS

Siblings reported similar distress as healthy control participants during provocation, and significantly less than patients. There was no significant three-group difference in activation during fear provocation or regulation. Three-group comparisons showed that patients had higher amygdala and dorsomedial prefrontal cortex activation during OCD-related emotion provocation and regulation, respectively, while siblings were intermediate between patients and control participants but not significantly different from either. Siblings showed higher left temporo-occipital activation (compared with both healthy control participants and patients) and higher frontolimbic connectivity (compared with patients) during OCD-related regulation.

CONCLUSIONS

Unaffected siblings do not show the same distress and amygdala activation during emotional provocation as OCD patients. Siblings show distinct activation in a temporo-occipital region, possibly related to compensatory cognitive control. This suggests that emotion regulation is not a strong endophenotype for OCD. When replicated, this contributes to our understanding of familial risk and resilience for OCD.

Emotional Processing in Obsessive-Compulsive Disorder: A Systematic Review and Meta-analysis of 25 Functional Neuroimaging Studies

BACKGROUND

Patients with obsessive-compulsive disorder (OCD) experience aversive emotions in response to obsessions, motivating avoidance and compulsive behaviors. However, there is considerable ambiguity regarding the brain circuitry involved in emotional processing in OCD, especially whether activation is altered in the amygdala.

METHODS

We conducted a systematic literature review and performed a meta-analysis-seed-based d mapping-of 25 whole-brain neuroimaging studies (including 571 patients and 564 healthy control subjects) using functional magnetic resonance imaging or positron emission tomography, comparing brain activation of patients with OCD and healthy control subjects during presentation of emotionally valenced versus neutral stimuli. Meta-regressions were employed to investigate possible moderators.

RESULTS

Patients with OCD, compared with healthy control subjects, showed increased activation in the bilateral amygdala, right putamen, orbitofrontal cortex extending into the anterior cingulate and ventromedial prefrontal cortex, and middle temporal and left inferior occipital cortices during emotional processing. Right amygdala hyperactivation was most pronounced in unmedicated patients. Symptom severity was related to increased activation in the orbitofrontal and anterior cingulate cortices and precuneus. Greater comorbidity with mood and anxiety disorders was associated with higher activation in the right amygdala, putamen, and insula as well as with lower activation in the left amygdala and right ventromedial prefrontal cortex.

CONCLUSIONS

Patients with OCD show increased emotional processing-related activation in limbic, frontal, and temporal regions. Previous mixed evidence regarding the role of the amygdala in OCD has likely been influenced by patient characteristics (such as medication status) and low statistical power.

Impact of treatment on resting cerebral blood flow and metabolism in obsessive compulsive disorder: a meta-analysis

Neurobiological models of obsessive-compulsive disorder (OCD) posit that its clinical symptoms such as repetitive thoughts and behaviors are related to hyperactivity in the cortico-striato-thalamo-cortical (CSTC) circuit. Small scale neuroimaging studies have shown that treatment of OCD is associated with reduced activity across different brain structures within this circuitry. We performed the first meta-analysis of positron emission tomography (PET) and single photon emission computed tomography (SPECT) studies that investigated cerebral blood flow or glucose metabolism in patients with OCD before and after pharmacological or psychological treatment. We calculated standardized mean differences for the regions-of-interest most often reported. The meta-analysis revealed small reductions in activity in the caudate nucleus and orbitofrontal cortex after treatment with a serotonin reuptake inhibitor or cognitive behavioral therapy. Small reductions were also observed in the thalamus when one SPECT study with a large opposite effect was excluded from the analysis. Meta-regression analyses for the caudate nucleus showed no significant effect of the type of treatment, decrease in symptom severity, mean duration until the follow-up scan, or year of publication. These results show that pharmacological and psychological treatments reduce resting CSTC circuit activity, and provide further support for the CSTC circuit model in OCD.

Depression in patients with SAPHO syndrome and its relationship with brain activity and connectivity

BACKGROUND

Synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome is a rare disease and there is no related literature concerning psychiatric symptoms in SAPHO patients. Thus, we believe that this will be the first paper to explore the episode and the neurobiological basis of depression symptoms in SAPHO patients using resting state functional magnetic resonance imaging (rs-fMRI). Twenty-eight SAPHO patients and fifteen age- and gender- matched normal controls (NC) were consecutively submitted to psychiatric evaluation and rs-fMRI scanning.

RESULTS

46.2% (13/28) of SAPHO patients were diagnosed as depression. The local spontaneous activity study showed that depressed SAPHO (D-SAPHO) patients had decreased amplitude of low-frequency fluctuation (ALFF) in the bilateral ventrolateral prefrontal cortex (VLPFC, attributed to the anatomical structures of Brodmann's area 47, 45 and 44) and right dorsolateral prefrontal cortex (DLPFC, attributed to the anatomical structures of Brodmann's area 8, 9 and 46), increased ALFF in the bilateral middle temporal gyrus, when compared to non-depressed SAPHO (ND-SAPHO) patients. The functional connectivity (FC) study disclosed that D-SAPHO patients had an increased FC in the anterior portions of default mode network (DMN) (the bilateral inferior frontal cortex, anterior cingulate cortex and insula cortex), and a decreased FC in the posterior areas of DMN (left middle occipital cortex), when compared to ND-SAPHO patients. Furthermore, correlation analysis revealed that both ALFF and FC values were significantly correlated with depression scores of SAPHO patients.

CONCLUSION

These results prompt us to understand the underlying pathophysiological mechanism of depression in SAPHO syndrome, and demonstrate that abnormal brain functional areas may serve as effective biological indicators to monitor depression in the future.

Cognitive Dysfunction in Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a mental disorder featuring obsessions (intrusive thoughts) and compulsions (repetitive behaviors performed in the context of rigid rituals). There is strong evidence for a neurobiological basis of this disorder, involving limbic cortical regions and related basal ganglion areas. However, more research is needed to lift the veil on the precise nature of that involvement and the way it drives the clinical expression of OCD. Altered cognitive functions may underlie the symptoms and thus draw a link between the clinical expression of the disorder and its neurobiological etiology. Our extensive review demonstrates that OCD patients do present a broad range of neuropsychological dysfunctions across all cognitive domains (memory, attention, flexibility, inhibition, verbal fluency, planning, decision-making), but some methodological issues temper this observation. Thus, future research should have a more integrative approach to cognitive functioning, gathering contributions of both experimental psychology and more fundamental neurosciences.

Cognitive and emotional impairments in obsessive-compulsive disorder: Evidence from functional brain alterations

There is a common agreement on the existence of dysfunctional cortico-striatal-thalamus-cortical pathways in OCD. Despite this consensus, recent studies showed that brain regions other than the CSTC loops are needed to understand the complexity and diversity of cognitive and emotional deficits in OCD. This review presents examples of research using functional neuroimaging, reporting abnormal brain processes in OCD that may underlie specific cognitive/executive (inhibitory control, cognitive flexibility, working memory), and emotional impairments (fear/defensive, disgust, guilt, shame). Studies during resting state conditions show that OCD patients have alterations in connectivity not only within the CSTC pathways but also in more extended resting state networks, particularly the default mode network and the fronto-parietal network. Additionally, abnormalities in brain functioning have been found in several cognitive and emotionally task conditions, namely: inhibitory control (e.g., CSTC loops, fronto-parietal networks, anterior cingulate); cognitive flexibility (e.g., CSTC loops, extended temporal, parietal, and occipital regions); working memory (e.g., CSTC loops, frontal parietal networks, dorsal anterior cingulate); fear/defensive (e.g., amygdala, additional brain regions associated with perceptual - parietal, occipital - and higher level cognitive processing - prefrontal, temporal); disgust (e.g., insula); shame (e.g., decrease activity in middle frontal gyrus and increase in frontal, limbic, temporal regions); and guilt (e.g., decrease activity anterior cingulate and increase in frontal, limbic, temporal regions). These findings may contribute to the understanding of OCD as both an emotional (i.e., anxiety) and cognitive (i.e., executive control) disorder.