"Not just right experiences" in patients with Tourette syndrome: complex motor tics or compulsions?

Dorsal Striatal Functional Connectivity and Repetitive Behavior Dimensions in Children and Youths With Neurodevelopmental Disorders

BACKGROUND

Impairing repetitive behaviors are one of the core diagnostic symptoms in autism spectrum disorder and obsessive-compulsive disorder, but they also manifest in attention-deficit/hyperactivity disorder. Although the dorsal striatal circuit has been implicated in repetitive behaviors, extensive heterogeneity in and cross-diagnostic manifestations of these behaviors have suggested phenotypic and likely neurobiological heterogeneity across neurodevelopmental disorders (NDDs).

METHODS

Intrinsic dorsal striatal functional connectivity was examined in 3 NDDs (autism spectrum disorder, obsessive-compulsive disorder, and attention-deficit/hyperactivity disorder) and typically developing control participants in a large single-cohort sample (N = 412). To learn how diagnostic labels and overlapping behaviors manifest in dorsal striatal functional connectivity measured with functional magnetic resonance imaging, the main and interaction effects of diagnosis and behavior were examined in 8 models (2 seed functional connectivity [caudate and putamen] × 4 sub-behavioral domains [sameness/ritualistic, self-injury, stereotypy, and compulsions]).

RESULTS

The obsessive-compulsive disorder group demonstrated distinctive patterns in visual and visuomotor coordination regions compared with the other diagnostic groups. Lower-order repetitive behaviors (self-injury and stereotypy) manifesting across all participants were implicated in regions involved in motor and cognitive control, although the findings did not survive effects of multiple comparisons, suggesting heterogeneity in these behavioral domains. An interaction between self-injurious behavior and an attention-deficit/hyperactivity disorder diagnosis were observed on caudate-cerebellum functional connectivity.

CONCLUSIONS

These findings confirmed high heterogeneity and overlapping behavioral manifestations in NDDs and their complex underlying neural mechanisms. A call for diagnosis-free symptom measures that can capture not only observable symptoms and severity across NDDs but also the underlying functions and motivations of such behaviors across diagnoses is needed.

Co-morbid tics and stereotypies: a systematic literature review

BACKGROUND

Tics and stereotypies are childhood-onset repetitive behaviours that can pose significant diagnostic challenges in clinical practice. Both tics and stereotypies are characterised by a complex co-morbidity profile, however little is known about the co-occurrence of these hyperkinetic disorders in the same patient population.

OBJECTIVE

This review aimed to assess the relationship between tics and stereotypies when these conditions present in co-morbidity.

METHODS

We conducted a systematic literature review of original studies on co-morbid tics and stereotypies, according to the standards outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Our literature search identified six studies of suitable sample size (n ≥ 40) presenting data on the association between tics and stereotypies in otherwise typically developing patients. A considerable proportion (23%) of patients diagnosed with stereotypic movement disorder present with co-morbid tics (range 18-43%). Likewise, the prevalence of primary stereotypies is increased in patients with tic disorders such as Tourette syndrome (8%, range 6-12%).

DISCUSSION

Tics and stereotypies can often develop in co-morbidity. The association of tics and stereotypies in the same patient has practical implications, in consideration of the different treatment approaches. Future research should focus on the assessment and management of both conditions, particularly in special populations (e.g. patients with pervasive developmental disorders).

Current and emerging pharmacotherapeutic strategies for Tourette syndrome

INTRODUCTION

Tourette syndrome (TS) is a chronic tic disorder characterized by both motor and vocal tics. The vast majority of patients present with co-morbid behavioral problems, especially tic-related obsessive-compulsive behaviors and attention-deficit and hyperactivity disorder. Evidence-based guidelines on the pharmacotherapy of TS have become available in recent years.

AREAS COVERED

The main purpose of this paper is to provide an overview of the current and emerging pharmacotherapeutic strategies for TS. A comprehensive search for the literature on the pharmacotherapy of tics was conducted using multiple databases (MEDLINE, Scopus, Web of Science, and Google Scholar), without date limits.

EXPERT OPINION

In consideration of the heterogeneity of the TS phenotypes, pharmacotherapy should be tailored to the individual patient. The choice of the pharmacological agent should take into account both the efficacy-to-tolerability ratio and the presence of co-morbid conditions. Evidence-based pharmacotherapy should aim at improving health-related quality life within a dynamic framework that typically requires active monitoring of the clinical presentation and reevaluation of the treatment intervention over time.

The Phenomenon of Exquisite Motor Control in Tic Disorders and its Pathophysiological Implications

The unifying characteristic of movement disorders is the phenotypic presentation of abnormal motor outputs, either as isolated phenomena or in association with further clinical, often neuropsychiatric, features. However, the possibility of a movement disorder also characterized by supranormal or enhanced volitional motor control has not received attention. Based on clinical observations and cases collected over a number of years, we here describe the intriguing clinical phenomenon that people with tic disorders are often able to control specific muscle contractions as part of their tic behaviors to a degree that most humans typically cannot. Examples are given in accompanying video documentation. We explore medical literature on this topic and draw analogies with early research of fine motor control physiology in healthy humans. By systematically analyzing the probable sources of this unusual capacity, and focusing on neuroscientific accounts of voluntary motor control, sensory feedback, and the role of motor learning in tic disorders, we provide a novel pathophysiological account explaining both the presence of exquisite control over motor output and that of overall tic behaviors. We finally comment on key questions for future research on the topic and provide concluding remarks on the complex movement disorder of tic behaviors. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Challenges in the Diagnosis and Assessment in Patients with Tourette Syndrome and Comorbid Obsessive-Compulsive Disorder

Tourette syndrome (TS) is characterized by the presence of vocal and motor tics with an onset in childhood. In almost 80% of patients psychiatric comorbidities coexist, particularly, attention deficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD) or behavior (OCB), depression, anxiety, rage attacks, and self-injurious behaviour (SIB). In this review, we discuss current state of the art regarding diagnosis and assessment of tics and OCD in patients with TS as well as challenges related to differential diagnosis between tics and OCD-related phenomena based on a systematic literature search. While in most cases clinical symptoms can be easily classified as either tics or OCB/OCD, some phenomena lay on the frontier between tics and compulsions/obsessions. For example, compulsions may resemble tics and, vice versa, sequences of motor tics may be misdiagnosed as compulsions. Accordingly, the terms "compulsive tics" and "cognitive tics" have been introduced. The most common and typical OCD symptom in patients with TS are "just right" phenomena, which also may show an overlap with tics, since patients may perform tics repeatedly until this feeling is achieved. Similarly, repetitive behaviors in patients with TS may manifest in a more "tic-like" or a more "OCD-like" type. Furthermore, SIB shows similarities with both tics and OCD. Until today, it is unclear how to classify this symptom best, although from most recent research a closer relationship between SIB and tics is suggested. In this review, in addition, we illustrate differences of the clinical spectrum of OCD in patients with TS compared to those with "pure OCD" without tics. To assess tics, the revised version of the Yale Global Tic Severity Scale (YGTSS-R) should be used, while for the assessment of OCD, the Yale Brown Obsessive Compulsive Disorder Scale (Y-BOCS) is recommended. Finally, we briefly summarize treatment strategies for tics and OCB/OCD in patients with TS.

Sensory symptoms in body-focused repetitive behaviors, restless legs syndrome, and Tourette syndrome: An overlap?

Tourette syndrome (TS) is a neurodevelopmental condition characterized by multiple tics. Sensory symptoms play a key role in the clinical phenomenology and pathophysiology of TS, as most patients report premonitory urges driving tic expression. Interestingly, sensory symptoms have also been reported in other conditions characterized by repeated behaviors. This review explores the nature of sensory symptoms reported by patients with body focused repetitive behaviors (BFRBs, especially trichotillomania and skin picking disorder) and restless legs syndrome (RLS) in comparison to TS. A sense of mounting inner tension and reinforcement mechanisms driven by gratification and relief on expression of the tic or repetitive behavior appear to be implicated across all conditions. Subjective urges can be temporarily suppressed by patients with TS and selected BFRBs, whereas patients with RLS tend to report dysesthesia more frequently than a suppressible urge to move. The observed similarities in the phenomenology of sensory symptoms across these conditions raise the possibility of a comparable underlying pathophysiology. Preliminary findings suggest an overlap of neural pathways encompassing the insula, basal ganglia (putamen), and posterior cingulate cortex.

The severity of obsessive-compulsive symptoms in Tourette syndrome and its relationship with premonitory urges: a meta-analysis

OBJECTIVES

Nearly half of the patients with Tourette Syndrome (TS) present with comorbid Obsessive-Compulsive Symptoms (OCS) and premonitory urges (PUs). However, inconsistent results have been found in the correlation between PUs and OCS in patients with TS.

METHODS

A meta-analysis was applied to identify the severity of OCS and its correlation with PUs in TS patients. Subgroup and meta-regression analyses were used to identify potential heterogeneity.

RESULTS

A total of 13 studies, including 576 patients, were enrolled in this study. The pooled correlation coefficient (r) was 0.29 (95% confidence interval: 0.18, 0.38) and heterogeneity (I²) of pooled r was 40% based on a fixed-effect model. The mean level of OCS based on the assessment of Children's Yale-Brown Obsessive-Compulsive Symptom Scale/Yale-Brown Obsessive-Compulsive Symptom Scale was 14.99 (95% CI: 11.41, 18.57) by a random effect model. Results of meta-regression analysis demonstrated that the severity of tic symptoms based on the assessment of the Yale Global Tic Severity Scale was the predictor of severity of OCS (p = 0.018).

CONCLUSION

There was a mild positive correlation between the PUs and OCS in patients with TS. The severity of OCS in TS patients was mild to moderate and positively predicted by the severity of tic symptoms.

Sensory hypersensitivity in Tourette syndrome: A review

Tourette syndrome (TS) is a neurodevelopmental disorder defined by tics, but most patients also experience bothersome sensory phenomena, in the form of premonitory urges and/or sensory hypersensitivity. Whereas premonitory urges are temporally paired with tics, sensory hypersensitivity is a constant, heightened awareness of external and/or internal stimuli. The intensity of sensory hypersensitivity does not strongly correlate with the severity of tics or premonitory urges, suggesting it is a dissociable clinical phenomenon. At least 80% of TS patients report subjectively enhanced perception of various sensory stimuli. These same patients demonstrate normal static detection thresholds. However, individuals with TS habituate abnormally to repetitive stimuli, indicating incapacity to appropriately filter redundant sensory input, i.e. impaired sensory gating. Physiologic support for this hypothesis is provided by abnormal pre-pulse inhibition (PPI) and event-related potential (ERP) investigations. Preclinical data implicates parvalbumin-positive (PV+) interneuron dysfunction in altered sensory gating in TS and other neurodevelopment disorders. Studies probing TS sensory hypersensitivity must methodically account for comorbid psychiatric conditions, namely obsessive compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), and autism spectrum disorder (ASD), as these entities appear to involve pathophysiologic processes shared with TS. The presence of psychiatric comorbidities in TS is associated with even more profound sensory processing dysfunction. A deepened understanding of TS sensory hypersensitivity will afford novel insights into disease mechanisms, clinical phenotype, and therapeutic management.

Social Cognition in Gilles de la Tourette Syndrome

Abstract. Research on the neural mechanisms underlying Gilles de la Tourette syndrome (GTS) has mostly concentrated on abnormalities in basal ganglia circuits. Recent alternative accounts, however, focused more on social and affective aspects. Individuals with GTS show peculiarities in their social and affective domain, including echophenomena, coprolalia, and nonobscene socially inappropriate behavior. This article reviews the experimental and theoretical work done on the social symptoms of GTS. We discuss the role of different social cognitive and affective functions and associated brain networks, namely, the social-decision-making system, theory-of-mind functions, and the so-called “mirror-neuron” system. Although GTS affects social interactions in many ways, and although the syndrome includes aberrant social behavior, the underlying cognitive, affective, and neural processes remain to be investigated.

The Correlation Between the Severity of Premonitory Urges and Tic Symptoms: A Meta-Analysis

Objectives: Premonitory urges (PUs) are defined as sensory experiences of pre-tic inner tension. Evidence suggests that most patients with Tourette syndrome experience PUs, which are transiently relived by the expression of tics. However, recent studies have revealed inconsistent results regarding the correlation between the severity of PUs and the severity of tic symptoms. Methods: A meta-analysis was performed to confirm the correlation between the severity of the urge and the severity of the expression of the tic. In total, 10 studies involving 626 patients with tic disorders were included in this meta-analysis. Results: The correlation coefficient (r) was extracted from each selected study, and a pooled correlation coefficient (r) and its 95% confidence intervals (CIs) were calculated. Sensitivity and subgroup analyses were performed to identify the potential sources of heterogeneity. The pooled correlation coefficient (r) of the relationship between the severity of PUs and tic symptoms was 0.296 (95% CI: 0.215-0.376) with an I² of 15.2% (95% CI: 0.00-56.5) based on a fixed effects model. The correlation was stronger in adults than in children (p = 0.03). Conclusion: A slight to moderate positive correlation was observed between the severity of PUs and tic symptoms. This correlation may be affected by the age of the patients. Further research should seek to elucidate the relationships among PUs, tic suppression, and tic expression to support the development of behavioral intervention therapies to reduce tic symptoms.

Clinical Aspects of Premonitory Urges in Patients with Tourette's Disorder

Most patients with Tourette’s disorder experience an uncomfortable sensory phenomenon called the premonitory urge immediately before experiencing tics. It has been suggested that premonitory urges are associated with comorbidities such as obsessive compulsive disorder, anxiety disorders, and attention-deficit/hyperactivity disorder, although these associations have been inconsistent. Most patients experience tics as a result of the premonitory urges, and after the tics occur, most patients report that the premonitory urges are temporarily relieved. As a consequence, several studies have assessed the premonitory urge and its potential therapeutic utility. Based on the concept that the premonitory urge induces tics, behavioral treatments such as Exposure and Response Prevention and Habit Reversal Therapy have been developed. However, it is still unclear whether habituation, the main mechanism of these therapies, is directly related to their effectiveness. Moreover, the observed effects of pharmacological treatments on premonitory urges have been inconsistent.

Systematic review of co-occurring OCD and TD: Evidence for a tic-related OCD subtype?

OBJECTIVE

The aim of this review is to summarize the current knowledge of associated features of co-occurring obsessive-compulsive disorder (OCD) and tic disorders (TD) and to critically evaluate hypotheses regarding the nature of their comorbidity.

METHOD

We conducted a systematic review following PRISMA guidelines. To this aim, the PubMed, PsychInfo and ISI Web of Knowledge databases were searched up to August 30, 2018. For gender and age-of-onset we additionally conducted meta-analyses.

RESULTS

One hundred eighty-nine studies met inclusion criteria. We substantiate some acknowledged features and report evidence for differential biological mechanisms and treatment response. In general, studies were of limited methodological quality.

CONCLUSIONS

Several specific features are reliable associated with co-occurring OCD + TD. The field lacks methodological sound studies. The review found evidence against and in favor for different hypotheses regarding the nature of comorbidity of OCD and TD. This could indicate the existence of a stepwise model of co-morbidity, or could be an artefact of the low methodological quality of studies.

Sensory aspects of Tourette syndrome

Motor and vocal tics have long been recognised as the core features of Tourette syndrome (TS). However, patients' first-person accounts have consistently reported that these involuntary motor manifestations have specific sensory correlates. These sensory symptoms are often described as feelings of mounting inner tension ("premonitory urges") and are transiently relieved by tic expression. Multimodal hypersensitivity to external stimuli, perceived as triggers and/or exacerbating factors for specific tic symptoms, is also commonly reported by patients with TS. This article focuses on the rapidly expanding literature on the clinical and neurobiological aspects of the premonitory urge and multimodal hypersensitivity in patients with TS, with particular attention to pathophysiological mechanisms and possible treatment implications. These findings suggest that TS is a neurobehavioural condition characterised by intrinsic perceptual abnormalities involving the insula and sensorimotor areas, in addition to basal ganglia dysfunction. Further research will clarify the role of sensory symptoms in TS, as well as the effects of external sensory input on underlying motor abnormalities.

Social cognition and self-other distinctions in neuropsychiatry: Insights from schizophrenia and Tourette syndrome

Impairments in social cognition may reflect dysfunction of disorder specific or disorder general mechanisms. Although cross-disorder comparison may prove insightful, few studies have compared social cognition in different neuropsychiatric disorders. Parallel investigation of schizophrenia and Tourette syndrome (TS) is encouraged by similarities including the presence of problematic social behavior, echophenomena, emotional dysregulation and dopamine dysfunction. Focusing on tests of social cognition administered in both disorders, this review aims to summarize behavioral, neurophysiological and neuroimaging findings, before exploring how these may contribute to clinical symptoms. Studies investigating social cognition (imitation, emotion recognition, and understanding of beliefs or intentions) in patients with schizophrenia or TS were identified through Web of Science and PubMed searches. Although findings indicate that social cognitive deficits are more apparent in schizophrenia, adults with TS can exhibit similar task performance to patients with paranoia. In both disorders, behavioral and neuroimaging findings raise the possibility of increased internal simulation of others' actions and emotions, in combination with a relative under-application of mentalizing. More specifically, dysfunction in neurobiological substrates such as temporo-parietal junction and inferior frontal gyrus may underlie problems with self-other distinctions in both schizophrenia and TS. Difficulties in distinguishing between actions and mental states linked to the self and other may contribute to a range of psychiatric symptoms, including emotional dysregulation, paranoia, social anhedonia and socially disruptive urges. Comparing different patient populations could therefore reveal common neuro-cognitive risk factors for the development of problematic social behaviors, in addition to markers of resilience, coping strategies and potential neuro-compensation mechanisms.

Pediatric obsessive-compulsive disorder with tic symptoms: clinical presentation and treatment outcome

Some studies have shown that children and adolescents with obsessive-compulsive disorder (OCD) and co-morbid tics differ from those without co-morbid tics in terms of several demographic and clinical characteristics. However, not all studies have confirmed these differences. This study examined children and adolescents with OCD and with possible or definite tic specifiers according to the DSM-5 in order to see whether they differ from patients without any tic symptoms regarding clinical presentation and outcome of cognitive behavioral therapy (CBT). The full sample included 269 patients (aged 7-17) with primary DSM-IV OCD who had participated in the Nordic Long-term Treatment Study (NordLOTS). Symptoms of tics were assessed using the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS-PL). One or more tic symptoms were found in 29.9% of participants. Those with OCD and co-morbid tic symptoms were more likely male, more likely to have onset of OCD at an earlier age, and differed in terms of OCD symptom presentation. More specifically, such participants also showed more symptoms of OCD-related impairment, externalization, autism spectrum disorder (ASD), social anxiety, and attention-deficit/hyperactivity disorder (ADHD). However, the two groups showed no difference in terms of OCD severity or outcome of CBT. Children and adolescents with OCD and co-morbid tic symptoms differ from those without tic symptoms in several aspects of clinical presentation, but not in their response to CBT. Our results underscore the effectiveness of CBT for tic-related OCD.

CLINICAL TRIALS REGISTRATION

Nordic Long-term Obsessive-Compulsive Disorder (OCD) Treatment Study; www.controlled-trials.com ; ISRCTN66385119.

A search for the common ground between Tic; Obsessive-compulsive and Autism Spectrum Disorders: part I, Tic disorders

This article is the first of four articles designed to explore the complex interrelationship between Autism Spectrum Disorders (ASD); Obsessive compulsive and Related Disorders (OCRD) and Tic Disorders/Tourette's Syndrome (TD/TS). We begin with an overview TD/TS and follow-up with reviews of OCRD and ASD. The final article in this series represents a synthesis of the neurobiological and genetic markers shared by patients presenting with all three syndromes. The goal is to describe the complex endophenotype of these patients in an effort to better define gene markers that underlie these heterogeneous clinical syndromes. Tic disorders (TD) are a collection of hyperkinetic movements that begin in early childhood. Tics are transient for most affected preschool children but a subgroup development persistent movements or progress to develop Tourette Syndrome (TS). TDs as a group display high heritability rates but definitive gene markers still elude us. The difficulty defining genetic markers is in large part due to the diverse neurodevelopmental trajectory, changing topography and typology, development of a broad spectrum of neurocognitive and behavioral complications, and a mixed pattern of psychiatric comorbidities.

Distinguishing Fear Versus Distress Symptomatology in Pediatric OCD

Prior research has identified OCD subtypes or "clusters" of symptoms that differentially relate to clinical features of the disorder. Given the high comorbidity between OCD and anxiety, OCD symptom clusters may more broadly associate with fear and/or distress internalizing constructs. This study examines fear and distress dimensions, including physical concerns (fear), separation anxiety (fear), perfectionism (distress), and anxious coping (distress), as predictors of previously empirically-derived OCD symptom clusters in a sample of 215 youth diagnosed with primary OCD (ages 7-17, mean age = 12.25). Self-reported separation fears predicted membership in Cluster 1 (aggressive, sexual, religious, somatic obsessions, and checking compulsions) while somatic/autonomic fears predicted membership in Cluster 2 (symmetry obsessions and ordering, counting, repeating compulsions). Results highlight the diversity of pediatric OCD symptoms and their differential association with fear, suggesting the need to carefully assess both OCD and global fear constructs that might be directly targeted in treatment.

Neurobiology of the Premonitory Urge in Tourette's Syndrome: Pathophysiology and Treatment Implications

Motor and vocal tics are relatively common motor manifestations identified as the core features of Tourette's syndrome (TS). Although traditional descriptions have focused on objective phenomenological observations, such as anatomical location, number and frequency of tics, patients' first-person accounts have consistently reported characteristic subjective correlates. These sensory phenomena are often described as a feeling of mounting inner tension or urge to move ("premonitory urge"), which is transiently relieved by tic expression. This article reviews the existing literature on the clinical and neurobiological aspects of the premonitory urge in patients with TS, with focus on its pathophysiology and possible treatment implications.

New Insights into Clinical Characteristics of Gilles de la Tourette Syndrome: Findings in 1032 Patients from a Single German Center

Background: Gilles de la Tourette syndrome (TS) is a complex neuropsychiatric disorder defined by the presence of motor and phonic tics, but often associated with psychiatric comorbidities. The main objective of this study was to explore the clinical presentation and comorbidities of TS.

Method: We analyzed clinical data obtained from a large sample (n = 1032; 529 children and 503 adults) of patients with tic disorders from one single German TS center assessed by one investigator. Data was collected with the help of an expert-reviewed semi-structured interview, designed to assess tic severity and certain comorbidities. Group comparisons were carried out via independent sample t-tests and chi-square tests.

Results: The main findings of the study are: (1) tic severity is associated with the presence of premonitory urges (PU), copro-, echo-, and paliphenomena and the number of comorbidities, but not age at tic onset; it is higher in patients with comorbid obsessive-compulsive disorder (OCD) than in patients with comorbid attention deficit/hyperactivity disorder (ADHD). (2) PU were found to be highly associated with “not just right experiences” and to emerge much earlier than previously thought alongside with the ability to suppress tics (PU in >60% and suppressibility in >75% at age 8–10 years). (3) Self-injurious behavior (SIB) is highly associated with complex motor tics and coprophenomena, but not with OCD/obsessive-compulsive behavior (OCB). While comorbid ADHD is associated with a lower ability to suppress tics, comorbid depression is associated with sleeping problems.

Discussion: Our results demonstrate that tic severity is not influenced by age at onset. From our data, it is suggested that PU represent a specific type of “not just right experience” that is not a prerequisite for tic suppression. Comorbid ADHD reduces patients' ability of successful tic suppression. Our data suggest that SIB belongs to the coprophenomena spectrum and hence should be conceptualized as a complex tic rather than a compulsion. Finally, this study strongly supports the hypothesis that TS+OCD is a more severe form of TS and that comorbid OCD/OCB, depression, and anxiety belong to the TS spectrum, while ADHD should be better conceptualized as a separate problem.

An empirical investigation of incompleteness in a large clinical sample of obsessive compulsive disorder

Obsessive Compulsive Disorder (OCD) is a disorder with heterogeneous clinical presentations. To advance our understanding of this heterogeneity we investigated the prevalence and clinical features associated with incompleteness (INC), a putative underlying core feature of OCD. We predicted INC would be prominent in individuals with OCD and associated with greater severity and impairment. We examined the impact of INC in 307 adults with primary OCD. Participants with clinically significant INC (22.8% of the sample) had significantly greater OCD severity, greater rates of comorbidity, poorer ratings of functioning, lower quality of life, and higher rates of unemployment and disability. Participants with clinically significant INC were also more likely to be diagnosed with OCPD and to endorse symmetry/exactness obsessions and ordering/arranging compulsions than those who reported low INC. Our findings provide evidence that INC is associated with greater severity, comorbidity, and impairment, highlighting the need for improved assessment and treatment of INC in OCD.

Sensory Phenomena in Tourette Syndrome: Their Role in Symptom Formation and Treatment

The primary symptoms of Tourette Syndrome (TS) are motor and vocal tics, but increasingly, researchers have examined the role of sensory phenomena in biobehavioral models of the disorder. These sensory phenomena involve tic-related premonitory urge sensations as well as potential abnormalities in the perceptual and behavioral experiences associated with external sensory input. As such, dysfunctional sensorimotor integration might represent a key facet of TS pathology. The current paper reviews the literature on sensory phenomena in tic disorders and highlights possible connections to TS symptoms and directions for future research.

The sense of incompleteness as a motivator of obsessive-compulsive symptoms: an empirical analysis of concepts and correlates

Contemporary models of obsessive-compulsive disorder emphasize the importance of harm avoidance (HA) and related dysfunctional beliefs as motivators of obsessive-compulsive (OC) symptoms. Recently, there has been a resurgence of interest in Janet's (1908) concept of incompleteness (INC) as another potentially important motivator. Contemporary investigators define INC as the sense that one's actions, intentions, or experiences have not been properly achieved. Janet defined INC more broadly to include alexithymia, depersonalization, derealization, and impaired psychological mindedness. We conducted two studies to address four issues: (a) the clinical correlates of INC; (b) whether INC and HA are distinguishable constructs; (c) whether INC predicts OC symptoms after controlling for HA; and (d) the relative merits of broad versus narrow conceptualizations of INC. Study 1 was a meta-analysis of the clinical correlates of narrowly defined INC (16 studies, N=5,940). INC was correlated with all types of OC symptoms, and was more strongly correlated with OC symptoms than with general distress. Study 2 (N=534 nonclinical participants) showed that (a) INC and HA were strongly correlated but factor analytically distinguishable; (b) INC statistically predicted all types of OC symptoms even after controlling for HA; and (c) narrow INC was most strongly correlated with OC symptoms whereas broad INC was most strongly correlated with general distress. Although the findings are limited by being correlational in nature, they support the hypothesis that INC, especially in its narrow form, is a motivator of OC symptoms.