The neurobiology of obsessive-compulsive personality disorder: a systematic review

Examining relationships among NODDI indices of white matter structure in prefrontal cortical-thalamic-striatal circuitry and OCD symptomatology

Obsessive-compulsive disorder is a psychiatric disorder characterized by intrusive thoughts and repetitive behaviors. There are two prominent features: Harm Avoidance (HA) and Incompleteness (INC). Previous resting-state studies reported abnormally elevated connectivity between prefrontal cortical (PFC) and subcortical regions (thalamus, striatum) in OCD participants. Yet, little is known about the white matter (WM) structural abnormalities in these connections. Using brain parcellation and segmentation, whole brain tractography, and Neurite Orientation Dispersion and Density Imaging (NODDI), we aimed to characterize WM structural abnormalities in OCD vs. healthy controls and determine the extent to which NODDI indices of these connections were associated with subthreshold-threshold HA, INC and overall OCD symptom severity across all participants. Four PFC regions were segmented: ventral medial (vmPFC), ventrolateral (vlPFC), dorsomedial (dmPFC), and dorsolateral (dlPFC). NODDI Neurite Density (NDI) and Orientation Dispersion (ODI) indices of WM structure were extracted from connections between these PFC regions and the thalamus (42 OCD, 44 healthy controls, mean age[SD] = 23.65[4.25]y, 63.9% female) and striatum (38 OCD, 41 healthy controls, mean age[SD] = 23.59[4.27]y, 64.5% female). Multivariate analyses of covariance revealed no between-group differences in these indices. Multivariate regression models revealed that greater NDI in vmPFC-thalamus, greater NDI and ODI in vmPFC-striatum, and greater NDI in dmPFC-thalamus connections were associated with greater INC severity (Q ≤ 0.032). These findings highlight the utility of NODDI in the examination of WM structure in OCD, provide valuable insights into specific WM alterations underlying dimensional INC, and can facilitate the development of customized treatments for OCD individuals with treatment-resistant symptoms.

Obsessive-Compulsive Disorder Comorbid With or Without Obsessive-Compulsive Personality Disorder: Conceptual Implications, Clinical Correlates, and Brain Morphometries

BACKGROUND

Obsessive-compulsive disorder (OCD) is often comorbid with obsessive-compulsive personality disorder (OCPD). The relationship between OCD and OCPD is complex, and the impact of comorbid OCPD on OCD remains underexplored, necessitating further research. In this study, we aimed to investigate the clinical correlates and brain morphometries associated with comorbid OCPD in a large sample of unmedicated patients with OCD.

METHODS

A total of 248 unmedicated patients diagnosed with OCD (45 comorbid with OCPD) were included in this study. All participants were assessed for OCD symptoms, OCPD traits, obsessive beliefs, depression, and anxiety. Among them, 145 patients (23 comorbid with OCPD) volunteered to receive magnetic resonance imaging brain scans.

RESULTS

Approximately 18% (45/248) of patients with OCD were comorbid for OCPD (OCD+OCPD). Patients with OCD+OCPD exhibited more severe OCD symptoms, obsessive beliefs, depression, and anxiety than OCD patients without OCPD. Additionally, the severity of OCPD was positively correlated with OCD symptoms and obsessive beliefs. Furthermore, patients with OCD+OCPD exhibited increased cortical complexity in the left superior parietal lobule and left precuneus, which mediated the relationship between OCPD and OCD symptoms only in OCD patients without OCPD.

CONCLUSIONS

The co-occurrence of OCPD may contribute to the heightened severity of psychopathological symptoms and associated brain morphological alterations in patients with OCD, indicating distinct but interrelated constructs between these 2 disorders.

Specific Patterns of Endogenous Functional Connectivity Are Associated With Harm Avoidance in Obsessive-Compulsive Disorder

BACKGROUND

Individuals with obsessive-compulsive disorder (OCD) show persistent avoidance behaviors, often in the absence of actual threat. Quality-of-life costs and heterogeneity support the need for novel brain-behavior intervention targets. Informed by mechanistic and anatomical studies of persistent avoidance in rodents and nonhuman primates, our goal was to test whether connections within a hypothesized persistent avoidance-related network predicted OCD-related harm avoidance (HA), a trait measure of persistent avoidance. We hypothesized that 1) HA, not an OCD diagnosis, would be associated with altered endogenous connectivity in at least one connection in the network; 2) HA-specific findings would be robust to comorbid symptoms; and 3) reliable findings would replicate in a holdout testing subsample.

METHODS

Using resting-state functional connectivity magnetic resonance imaging, cross-validated elastic net for feature selection, and Poisson generalized linear models, we tested which connections significantly predicted HA in our training subsample (n = 73; 71.8% female; healthy control group n = 36, OCD group n = 37); robustness to comorbidities; and replicability in a testing subsample (n = 30; 56.7% female; healthy control group n = 15, OCD group n = 15).

RESULTS

Stronger inverse connectivity between the right dorsal anterior cingulate cortex and right basolateral amygdala and stronger positive connectivity between the right ventral anterior insula and left ventral striatum were associated with greater HA across groups. Network connections did not discriminate OCD diagnostic status or predict HA-correlated traits, suggesting sensitivity to trait HA. The dorsal anterior cingulate cortex-basolateral amygdala relationship was robust to controlling for comorbidities and medication in individuals with OCD and was also predictive of HA in our testing subsample.

CONCLUSIONS

Stronger inverse dorsal anterior cingulate cortex-basolateral amygdala connectivity was robustly and reliably associated with HA across groups and in OCD. Results support the relevance of a cross-species persistent avoidance-related network to OCD, with implications for precision-based approaches and treatment.

Increased error rate and delayed response to negative emotional stimuli in antisaccade task in obsessive-compulsive disorder

Ample evidence links impaired inhibitory control, attentional distortions, emotional dysregulation, and obsessive-compulsive disorder (OCD). However, it remains unclear what underlies the deficit that triggers the OCD cycle. The present study used an antisaccade paradigm with emotional valences to compare eye movement patterns reflecting inhibitory control and attention switching in OCD and healthy control groups. Thirty-two patients with OCD and thirty healthy controls performed the antisaccade task with neutral, positive, and negative visual images served as fixation stimuli. Presentation of the fixation stimulus overlapped with target stimuli appearance for 200 ms. The OCD group showed more errors to negative stimuli than the control group and they also performed antisaccades more slowly to negative and neutral stimuli than positive ones. Other patterns, including mean gaze velocity of correct antisaccades did not differ between groups. The mean gaze velocity of correct antisaccades was higher for negative and positive stimuli than for neutral stimuli in both groups. The peak velocity parameter did not show any differences either between groups or between valences. The findings support a hypothesis that an attentional bias toward negative stimuli interferes with inhibitory control in OCD.

Obsessive-Compulsive Disorder With Co-Occurring Obsessive-Compulsive Personality Disorder: A Practice Focused Review

This review article addresses the frequently noted comorbidity between obsessive-compulsive disorder (OCD) and obsessive-compulsive personality disorder (OCPD). We begin by reviewing the recent empirical literature on the co-occurrence of these two conditions and the functional consequences of comorbid OCPD on OCD. We describe theoretical conceptualizations of the links between these disorders, including shared mechanisms that may drive the association between these two distinct conditions. We then provide an overview of diagnostic measures for OCPD and differential diagnosis. We also review data on the impact of comorbid OCPD on cognitive-behavioral treatment for OCD, including how to address potential treatment barriers through which OCPD may complicate OCD treatment. Lastly, we conclude with directions for future research.

Efficacy and tolerability of pharmacotherapy for obsessive-compulsive personality disorder: a systematic review of randomized controlled trials

INTRODUCTION

Although obsessive-compulsive personality disorder (OCPD) is one of the most prevalent personality disorders, it is one of the least studied. There is debate as to whether pharmacotherapy is efficacious for OCPD. We aimed to systematically evaluate the efficacy and tolerability of pharmacotherapy for OCPD.

AREAS COVERED

This systematic review found two randomized controlled trials investigating pharmacotherapy of OCPD. In a study of major depression (n = 308) with comorbid OCPD (n = 71), citalopram was more effective for OCPD than sertraline with fewer drop-outs from treatment. In a small study of OCPD (n = 24), fluvoxamine was more effective than placebo, and there was a low drop-out rate. Risk of bias and quality assessment of these studies was not possible, and findings have very low levels of certainty.

EXPERT OPINION

Two studies provide preliminary evidence in support of citalopram and fluvoxamine for OCPD. Further randomized controlled trials are required before firm conclusions can be drawn regarding efficacy of pharmacotherapy for OCPD.

Individual obsessive-compulsive traits are associated with poorer adjustment to the easing of COVID-19 restrictions

BACKGROUND

As COVID-19 restrictions ease, the public are expected to relinquish previously enforced safety behaviors and resume a more normal lifestyle. Despite these aims, our recent survey of 438 adults from the general population, during a temporary release of lockdown in the United Kingdom (July-November 2020), showed that 25% of the public find re-adjustment problematic. This was especially the case in those with a history of mental disorder and obsessive-compulsive (OC) traits and symptoms, including rigidity as measured by a neurocognitive test of attentional flexibility. To aid in identifying those most at risk, we performed a secondary analysis on the data to determine which specific OC traits were related to specific aspects of behavioral adjustment.

METHODS

Correlational and multiple regression analyses were performed to determine associations between the eight individual personality traits constituting DSM-5 Obsessive-Compulsive Personality Disorder (OCPD), as measured by the self-rated Compulsive Personality Assessment Scale (CPAS) and a range of self-rated Post-Pandemic Adjustment Questionnaire items.

RESULTS

Three items on the Post-Pandemic Adjustment Questionnaire correlated with individual CPAS items: 'General difficulties adjusting' correlated with perfectionism, preoccupation with details, over-conscientiousness and need for control; 'social avoidance' correlated with perfectionism and preoccupation with details; and 'disinfecting behaviors' correlated with preoccupation with details and miserliness (Pearson's r - all p < .001). Intriguingly, none of the adjustment items correlated significantly with self-rated rigidity.

CONCLUSIONS

Several OCPD traits predict post-pandemic adjustment difficulties, but perfectionism and preoccupation-with-details showed the most robust correlations. These traits constitute a platform for the development of new screening and interventional strategies aimed at restoring public mental health and wellbeing. Cognitive rigidity may be more reliably evaluated using an objective form of assessment.