Schizotypy and smooth pursuit eye movements as potential endophenotypes of obsessive-compulsive disorder

Heart rate and heart rate variability in obsessive-compulsive disorder: Evidence from patients and unaffected first-degree relatives

Altered heart rate (HR) and heart rate variability (HRV) are common observations in psychiatric disorders. Yet, few studies have examined these cardiac measures in obsessive-compulsive disorder (OCD). The current study aimed to investigate HR and HRV, indexed by the root mean square of successive differences (RMSSD) and further time domain indices, as putative biological characteristics of OCD. Electrocardiogram was recorded during a five-minute resting state. Group differences between patients with OCD (n = 96), healthy participants (n = 112), and unaffected first-degree relatives of patients with OCD (n = 47) were analyzed. As potential moderators of group differences, we examined the influence of age and medication, respectively. As results indicated, patients with OCD showed higher HR and lower HRV compared to healthy participants. These group differences were not moderated by age. Importantly, subgroup analyses showed that only medicated patients displayed lower HRV compared to healthy individuals, while HR alterations were evident in unmedicated patients. Regarding unaffected first-degree relatives, group differences in HRV remained at trend level. Further, an age-moderated group differentiation showed that higher HRV distinguished relatives from healthy individuals in young adulthood, whereas at higher age lower HRV was indicative of relatives. Both the role of familial risk and medication in HRV alterations need further elucidation. Pending future studies, alterations in HR and potentially HRV might serve as useful indices to characterize the pathophysiology of OCD.

Along the fringes of Agency: neurodevelopmental account of the obsessive mind

The experiential core of the obsessive mind rests on subtle, primary mental phenomena (such as obsessions and so called "sensory phenomena") which precede and trigger behavioral compulsions. Converging evidence supports a possible pathophysiological role for altered corollary discharge (phenotypically expressed in sensorimotor symptoms and contributing to a reduced Sense of Agency [SoA]), in the neurodevelopment of obsessions and "sensory phenomena." In phenomenological terms, "sensory phenomena" may represent the subjective experiential resonance of an individual history of persistent inaccurate sensory predictions, whereas accompanying manifestations, such as the obsessive need for order and symmetry, may represent a compensatory attempt to mitigate "sensory phenomena" (eg, by increasing the sensory predictability of the surrounding world). Since disturbances of both SoA and Sense of Ownership have been thematized as potential pathogenetic factors in the neurodevelopment of the psychotic mind, a dimensional account of altered sensorimotor prediction may partly explain the affinities (and high comorbidity) between obsessive-compulsive disorder and schizophrenia spectrum disorders.

Schizotypal personality disorder in clinical obsessive-compulsive disorder samples: a brief overview

Obsessive-compulsive disorder (OCD) is a chronic and disabling mental disorder characterized by the presence of obsessions and/or compulsions that cause major distress and impair important areas of functioning. About 9 out of 10 patients with OCD have comorbid psychiatric diagnoses. A high proportion of clinically diagnosed OCD patients fulfill diagnostic criteria of a schizophrenia spectrum disorder, to the point that significant evidence in the literature supports the existence and the clinical relevance of a schizo-obsessive spectrum of disorders, including schizotypal personality disorder (SPD) with OCD (schizotypal OCD). In this paper, we provide a brief but comprehensive analysis of the literature on the clinical coexistence between OCD and SPD. The clinical validity of the so-called schizotypal OCD is analyzed through a comprehensive investigation of the relationship between SPD features and obsessive-compulsive phenomena in clinical OCD samples. This review describes the potential connections between OCD and SPD on the epidemiological, sociodemographic, psychopathological, and clinical levels. SPD is commonly observed in OCD patients: about 10% of OCD patients have a full categorical diagnosis of SPD. Early clinical identification of SPD features-and, more generally, of psychotic features and personality disorders-in OCD patients is strongly recommended. In fact, a proper and early diagnosis with early treatment may have benefits for prognosis. However, although schizotypal OCD seems to have clinical and predictive validity, further neurobiological and genetic studies on etiological specificity are warranted.

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.

Recent updates of eye movement abnormalities in patients with schizophrenia: A scoping review

AIM

Although eye-tracking technology expands beyond capturing eye data just for the sole purpose of ensuring participants maintain their gaze at the presented fixation cross, gaze technology remains of less importance in clinical research. Recently, impairments in visual information encoding processes indexed by novel gaze metrics have been frequently reported in patients with schizophrenia. This work undertakes a scoping review of research on saccadic dysfunctions and exploratory eye movement deficits among patients with schizophrenia. It gathers promising pieces of evidence of eye movement abnormalities in attention-demanding tasks on the schizophrenia spectrum that have mounted in recent years and their outcomes as potential biological markers.

METHODS

The protocol was drafted based on PRISMA for scoping review guidelines. Electronic databases were systematically searched to identify articles published between 2010 and 2020 that examined visual processing in patients with schizophrenia and reported eye movement characteristics as potential biomarkers for this mental illness.

RESULTS

The use of modern eye-tracking instrumentation has been reported by numerous neuroscientific studies to successfully and non-invasively improve the detection of visual information processing impairments among the screened population at risk of and identified with schizophrenia.

CONCLUSIONS

Eye-tracking technology has the potential to contribute to the process of early intervention and more apparent separation of the diagnostic entities, being put together by the syndrome-based approach to the diagnosis of schizophrenia. However, context-processing paradigms should be conducted and reported in equally accessible publications to build comprehensive models.

Impaired Corollary Discharge in Psychosis and At-Risk States: Integrating Neurodevelopmental, Phenomenological, and Clinical Perspectives

The brain is increasingly viewed in contemporary neuroscience as a predictive machine; its products, such as movements and decisions, are indeed accompanied by predictions of outcomes at distinct levels of awareness. In this conceptual review, we focus on corollary discharge, a basic neurophysiological mechanism that is allegedly involved in sensory prediction and contributes to the distinction between self-generated and externally generated actions. Failures in corollary discharge have been hypothesized as potentially relevant for the progressive development of positive psychotic symptoms such as passivity delusions and auditory verbal hallucinations. We articulate this framework adopting three confocal lenses, namely, the neurodevelopmental, phenomenological, and clinical perspectives. Converging evidence from these research domains indicates a possible developmental cascade leading to increased lifetime risk of psychosis. That is, early childhood alterations of corollary discharge mechanisms, endophenotypically expressed in motor impairment, may concur with a progressive fading of the feeling of self-agency on one's own experiences. Combined with other age-dependent situational challenges occurring along development, this may progressively hamper the ontogenesis of the embodied self, thereby facilitating the emergence of anomalous subjective experiences such as self-disorders (a longitudinal index of schizophrenia spectrum vulnerability) and broadly conceived clinical high-risk states. Overall, this condition increases the risk of developing passivity symptoms, phenotypically expressed in a severity gradient ranging from intrusive thoughts to passivity delusions and auditory verbal hallucinations. Empirical and clinical implications of this framework, as well as future scenarios, are discussed.

Impaired Antisaccades in Obsessive-Compulsive Disorder: Evidence From Meta-Analysis and a Large Empirical Study

Increasing evidence indicates that patients with obsessive-compulsive disorder (OCD) exhibit alterations in fronto-striatal circuitry. Performance deficits in the antisaccade task would support this model, but results from previous small-scale studies have been inconclusive as either increased error rates, prolonged antisaccade latencies, both or neither have been reported in OCD patients. In order to address this issue, we investigated antisaccade performance in a large sample of OCD patients (n = 169) and matched control subjects (n = 183). As impaired antisaccade performance constitutes a potential endophenotype of OCD, unaffected first-degree relatives of OCD patients (n = 100) were assessed, as well. Furthermore, we conducted a quantitative meta-analysis to integrate our data with previous findings. In the empirical study, OCD patients exhibited significantly increased antisaccade latencies, intra-subject variability (ISV) of antisaccade latencies, and antisaccade error rates. The latter effect was driven by errors with express latency (80-130 ms), as patients did not differ significantly from controls with regards to regular errors (>130 ms). Notably, unaffected relatives of OCD patients showed elevated antisaccade express error rates and increased ISV of antisaccade latencies, as well. Antisaccade performance was not associated with state anxiety within groups. Among relatives, however, we observed a significant correlation between antisaccade error rate and harm avoidance. Medication status of OCD patients, symptom severity, depressive comorbidity, comorbid anxiety disorders and OCD symptom dimensions did not significantly affect antisaccade performance. Meta-analysis of 10 previous and the present empirical study yielded a medium-sized effect (SMD = 0.48, p < 0.001) for higher error rates in OCD patients, while the effect for latencies did not reach significance owing to strong heterogeneity (SMD = 0.51, p = 0.069). Our results support the assumption of impaired antisaccade performance in OCD, although effects sizes were only moderately large. Furthermore, we provide the first evidence that increased antisaccade express error rates and ISV of antisaccade latencies may constitute endophenotypes of OCD. Findings regarding these more detailed antisaccade parameters point to potentially underlying mechanisms, such as early pre-stimulus inhibition of the superior colliculus.