Tic-related Obsessive-compulsive Disorder Research Articles

Pharmacological management of tourette's syndrome comorbid with obsessive-compulsive disorder in adult patients

AimsTourette's Syndrome (TS) is a neurodevelopmental disorder, which often presents in childhood and is hallmarked by motor and vocal tics. Obsessive-Compulsive Disorder (OCD) is a chronic neuropsychiatric condition characterised by intrusive thoughts and time-consuming repetitive behaviours. Research suggests that 15-20% of adult patients with TS will also meet the diagnostic criteria for OCD. Both illnesses appear to have neurobiological similarities but a differing course and clinical response to pharmacological treatments.Despite this, research into optimal management of adults with co-occurring TS or other tic disorders and OCD remains sparse. Comorbidities, are known to be poor predictor of response to selective serotonin reuptake inhibitors (SSRI) monotherapy in OCD and are often associated with treatment-refractory OCD. Similarly SSRI monotherapy in patients with OCD and comorbid TS can sometimes worsen motor tics (1 in 2000) and fail to improve OCD symptoms. In this review, we aim to evaluate evidence on the management of patients with co-occurring TS and OCD and address an important knowledge gap in clinical practice.MethodThis review was conducted in accordance with PRISMA Guidelines. We performed a search using PubMed, Cochrane Library and PsychINFO using the following Boolean Input “Tourettic-OCD” OR “tic-related OCD” OR ((OCD OR “obsessive-compulsive” OR “obsessive compulsive”) AND (Tourette OR “Tourette's” OR Tourettes OR tic))”. The search was conducted until January 2020. We then screened the articles of systematic reviews to extract additional studies from their reference lists.Result1888 studies were identified, of which 15 clinical trials were included in our systematic review. The presence of tics in patients with OCD are a major predictor for treatment-refractory OCD and a lack of improvement following monotherapy with SSRIs. Dual therapy with an SSRI and antipsychotics (particularly risperidone) are associated with improved outcomes in OCD patients with tics and TS patients with obsessive-compulsive symptoms. However, conjoint therapy with neuroleptics and SSRIs was only investigated when OCD burden was unsatisfactory following SSRI monotherapy.ConclusionThere are clinical implications when a patient with OCD also has a chronic tic disorder. The findings indicate the need for further research, particularly in the form of a larger cohort in randomised controlled trials, to determine when it is best to initiate patients with OCD and comorbid tic disorders on a dual antipsychotic-SSRI management strategy. Further evidence should also be done to determine other characteristics that predict an improvement to conjoint SSRI/neuroleptic therapy for effective symptom reduction.

Neurological Soft Signs and Clinical Features of Tic-Related Obsessive-Compulsive Disorder Indicate a Unique Subtype.

Tic-related obsessive-compulsive disorder (OCD) may be a unique OCD subtype. This study examined whether neurological soft signs (NSSs) of patients with tic-related and tic-free OCD enable discrimination of these subgroups. We used the Neurological Evaluation Scale to assess 32 patients with tic-related and 94 with tic-free OCD, as well as 84 controls. Most patients with tic-related OCD were male, with earlier illness onset and poorer insight scores than those of patients with tic-free OCD. Patients with tic-related OCD had poorer motor coordination, sensory integration, and motor sequencing than did tic-free patients. Logistic regression using NSS subscale scores predicted tic-related OCD. Patients with tic-related OCD displayed greater neurodevelopmental abnormalities than did tic-free patients. NSSs of the former group suggest the need to separate this subgroup. Our results also support the newly introduced tic-related specifier in the fifth edition of the Diagnostic and statistical manual of mental disorders.

A population-based family clustering study of tic-related obsessive-compulsive disorder

In the latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), obsessive-compulsive disorder (OCD) included a new “tic-related” specifier. However, strong evidence supporting tic-related OCD as a distinct subtype of OCD is lacking. This study investigated whether, at the population level, tic-related OCD has a stronger familial load than non-tic-related OCD. From a cohort of individuals born in Sweden between 1967 and 2007 (n = 4,085,367; 1257 with tic-related OCD and 20,975 with non-tic-related OCD), we identified all twins, full siblings, maternal and paternal half siblings, and cousins. Sex- and birth year-adjusted hazard ratios (aHR) were calculated to estimate the risk of OCD in relatives of individuals with OCD with and without comorbid tics, compared with relatives of unaffected individuals. We found that OCD is a familial disorder, regardless of comorbid tic disorder status. However, the risk of OCD in relatives of individuals with tic-related OCD was considerably greater than the risk of OCD in relatives of individuals with non-tic-related OCD (e.g., risk for full siblings: aHR = 10.63 [95% CI, 7.92–14.27] and aHR = 4.52 [95% CI, 4.06–5.02], respectively; p value for the difference < 0.0001). These differences remained when the groups were matched by age at first OCD diagnosis and after various sensitivity analyses. The observed familial patterns of OCD in relation to tics were not seen in relation to other neuropsychiatric comorbidities. Tic-related OCD is a particularly familial subtype of OCD. The results have important implications for ongoing gene-searching efforts.

Psychopharmacotherapy of Obsessive-Compulsive Symptoms within the Framework of Tourette Syndrome.

While Behavioral Therapy (BT) should be recommended as the first step in the treatment of OCD as well as TS, medication can be added for augmentation and in certain situations (e.g. family preference, BT not available or feasible) the priority may even reverse. This narrative review is given on the complexity of drug treatment in patients comorbid with obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) and other tic problems. OCD with TS is a co-occurring combination of the two generally delimitable, but in detail, also overlapping disorders which wax and wane with time but have different courses as well as necessities and options of treatment. Distinct subtypes like “tic-related OCD” are questionable. Obsessive-compulsive symptoms (OCS) and tics are frequently associated (OCS in TS up to 90%, tics in OCD up to 37%). Sensory-motor phenomena like urges and just-right feelings reflect some behavioral overlap. The main additional psychopathologies are attention-deficit hyperactivity disorder (ADHD), mood problems and anxiety. Also, hair pulling disorder and skin picking disorder are related to OCD with TS. Hence, the assessment and drug treatment of its many psychopathological problems need high clinical experience, careful planning, and ongoing evaluation/adaptation. Drugs are able to reduce clinical symptoms but cannot cure the disorders, which should be treated in parallel in their own right; i.e. for OCD serotonin reuptake inhibitors (SSRI) and for TS (tics), certain antipsychotics can be successfully prescribed. In cases of OCD with tics, when OCS responds only partially, an augmentation with antipsychotics (recommended: risperidone and aripiprazole) may improve OCS as well as tics. Also, the benzamide sulpiride, an atypical antipsychotics, may be beneficial in treating the combination of OCS, tics and anxious-depressive problems.Probably, any additional psychopathologies of OCD might attenuate the effectiveness of SSRI on OCS; on the other hand, in cases of OCD with tics, SSRI may reduce not only OCS but also stress sensitivity and emotional problems and thus leading to better selfregulatory abilities, useful to improve tic suppression.In sum, some clinical guidance can be given, but there remain many uncertainties because of a scarce database for psychopharmacotherapy in OCD with TS.

Tourette Syndrome and Chronic Tic Disorders: The Clinical Spectrum Beyond Tics.

The clinical surveillance and active management of Tourette syndrome (TS) and other primary chronic tic disorders cannot be limited to tics, as these patients manifest a spectrum of sensory-, behavioral-, cognitive-, and sleep-related problems that have a major impact on their functioning and quality of life, influencing enormously clinical decision making on a routine basis. The sensory phenomena of primary tic disorders consist of premonitory urges and heightened sensitivity to external somatosensory and interoceptive stimuli. Recent evidence suggests that raised interoceptive awareness may be related to the classical premonitory urges associated with tics. The burden of behavioral comorbidities is very important in determining the degree of disability of patients with primary tic disorders. Only 10%-15% of these patients presents exclusively with a tic disorder. Obsessive-compulsive disorder (OCD) are common in TS, and the clinical distinction between compulsions and complex tics may be difficult in some cases. "Tic-related OCD" represents a phenomenologically characteristic subtype of OCD, also associated with "just right" phenomena. Probably the presence of comorbid attention deficit/hyperactivity disorder is the main determinant of cognitive dysfunction in TS patients and influences heavily also the risk of developing disruptive behaviors. Mood and anxiety disorders, impulse control disorders, rage attacks, "impulsive" tic-like behaviors (e.g., nonobscene socially inappropriate behaviors, and self-injurious behaviors), and autism spectrum disorders complete the wide psychopathological spectrum of primary chronic tic disorders. Moreover, specific sleep abnormalities have been reported in TS patients, although more research is needed on this specific clinical problem. As in other areas of clinical neuroscience, a comprehensive approach to both motor and nonmotor aspects of this group of disorders will help personalizing treatment interventions and, ultimately, improve quality of care.

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

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

Tic-Related Versus Tic-Free Obsessive-Compulsive Disorder: Clinical Picture and 2-Year Natural Course.

The tic-related subtype of obsessive-compulsive disorder (OCD) has a distinct clinical profile. The course of tic-related OCD has previously been investigated in treatment studies, with inconclusive results. This study aimed to compare clinical profiles between tic-related and tic-free OCD patients and to establish the influence of tics on the 2-year natural course in adult OCD patients. Within the Netherlands OCD Association cohort, 377 patients with a current DSM-IV diagnosis of OCD were divided into a tic-related group (28%) and a tic-free group and compared on clinical variables with t tests or χ² tests. Linear mixed-model analyses were used to compare the 2-year course between the groups, with the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) as primary outcome measure. Data were collected from 2005 to 2007 and from 2007 to 2009. Compared to patients with tic-free OCD, those with tic-related OCD reported earlier disease onset (P = .009) and more symmetry/ordering symptoms (P = .002). Overall symptom severity was similar in both groups. Patients with tic-related OCD reported increased traits of attention-deficit hyperactivity (P < .001) and autism (P = .005) compared to the tic-free OCD group. Clinical improvement at 2-year follow-up (mean = 5.3-point decrease on the Y-BOCS, P < .001, 95% CI = 4.3 to 6.3) was not significantly moderated by tic status (P = .24). This remained unchanged after correcting for baseline differences. Tics do not critically affect the 2-year course of adult OCD, but tic-related OCD shows differences from tic-free OCD, such as early onset and increased autism and ADHD traits, that may indicate a neurodevelopmental subtype.

Approaches to the Diagnosis and Treatment of OCD with Comorbid Tic Disorders

Bidirectional overlap has long been described between obsessive–compulsive disorder (OCD) and tic disorders. Similar features, including underlying neurobiological genesis in frontal-striatal circuitry, familiality, relatively early onset, waxing and waning course, and overlapping phenomenology in repetitive behaviors, suggest different variations of the same disorder. Nevertheless, some differences have been described between OCD and tic disorders: tics begin early in childhood and typically attenuate or remit by late adolescence, whereas OCD tends to onset later and persist, and tic disorders are far more common in males than is the case in OCD. Individuals with OCD plus comorbid tics may represent a specific sub-type of OCD or tic disorders, and possess some important phenomenological differences from those with OCD without tics; for example, tic-related OCD tends to have earlier onset, higher prevalence in males, prominent symmetry, evening-up, counting, and “just-right” phenomenology, when compared with non-tic-related OCD. Recent DSM-5 classification changes now recognize presence of tics as a specifier in diagnosis of OCD; despite a 40 % prevalence rate of comorbid tics in childhood-onset OCD, there is still little data regarding risk factors, validated distinguishing features, course and treatment of this diagnostic group. Prominence of premonitory sensory phenomena, urges or sensations experienced prior to the repetitive behaviors, is no longer thought to distinguish complex motor tics from compulsions. Well established treatments of OCD include cognitive behavioral interventions and pharmacotherapy, specifically the serotonin re-uptake inhibitors (SRIs); although these treatments are also beneficial in tic-related OCD, some studies suggest that at least for pharmacotherapy, SRIs may not be as effective in OCD patients with comorbid tics. Given the frequent overlap of OCD and tics, and the recent designation of tic-related OCD as an OCD specifier, more investigation of the comorbid subtype is clearly needed.

The clinical utility of the tic-related obsessive-compulsive disorder diagnostic specifier.

The clinical utility of the tic-related obsessive-compulsive disorder diagnostic specifier.

Comorbid tics have no effect on response to cognitive-behavioral therapy in youth with obsessive-compulsive disorder

ABSTRACT FROM: Conelea CA, Walther WR, Freeman JB, et al . Tic-related obsessive-compulsive disorder (OCD): phenomenology and treatment outcome in the paediatric OCD treatment study II. J Am Acad Child...

Tactile processing in children and adolescents with obsessive–compulsive disorder

Many obsessive–compulsive disorder (OCD) patients experience sensory phenomena, such as bodily sensations and “just-right” perceptions accompanying compulsions. We studied tactile processing in OCD by psychophysical experiments targeting the somatosensory cortex. Thirty-two children and adolescents with OCD (8 tic-related, 19 with sensory phenomena (SP)) and their sex- and age-matched controls participated in the study. After clinical assessments, two questionnaires were completed for sensory problems (Sensory Profile and Touch Inventory for Elementary-School-Aged Children). The psychophysical experiments consisted of five tasks: simple reaction time, choice reaction time, dynamic (detection) threshold, amplitude discrimination, and amplitude discrimination with single-site adaptation. The tactile stimuli were sinusoidal mechanical vibrations (frequency: 25 Hz) applied on the fingertips. Just-noticeable differences (JNDs) were found in amplitude discrimination tasks. There was no difference between the OCD group and controls in detection thresholds. However, the OCD group (especially young males) had worse amplitude discrimination (i.e., higher JNDs) than controls. Young OCD participants had reduced adaptation than young controls. Tic-related OCD participants and those with SP had higher detection thresholds than those without. Additionally, the OCD group reported more problems than controls in the Emotional/Social subset of the Sensory Profile questionnaire. The discrimination results show altered tactile processing in OCD at suprathreshold levels. This can be explained by a scaling factor modifying the sensory signal with decreasing slope at higher input levels to achieve normal Weber fractions internally. Quadratic discriminant analysis gave the best positive (76%) and negative (60%) predictive values for classifying individuals (into “OCD” or “control” groups) based on psychophysical data alone.

Impact of Gender, Age at Onset, and Lifetime Tic Disorders on the Clinical Presentation and Comorbidity Pattern of Obsessive-Compulsive Disorder in Children and Adolescents.

Obsessive-compulsive disorder (OCD) is a heterogeneous disorder; therefore, there is a need for identifying more homogeneous subtypes. This study aimed to examine the clinical characteristics and comorbidity pattern of a large sample of pediatric OCD subjects, and to examine the impact of gender, age at onset, and lifetime tic disorders on the clinical presentation and comorbidity pattern. A total of 110 children and adolescents diagnosed with OCD were assessed using the Kiddle Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version (K-SADS-PL) for psychiatric comorbidity, and a clinical data form was filled out. The cutoff for differentiating prepubertal from adolescent onset was 11 years of age. A total of 83.6% of the subjects had at least one comorbid psychiatric disorder. Oppositional defiant disorder and contamination/somatic obsessions were significantly higher in males (p=0.036 and p=0.03, respectively) than in females. Depressive disorders and religious obsessions were significantly higher in the adolescent-onset group (p=0.02, p=0.05, respectively) whereas disruptive behavior disorders were higher in the prepubertal-onset group (p=0.037). Disruptive behavior disorders were significantly more frequent in the tic (+) group than in tic (-) group (p=0.021). There were differences in the comorbidity pattern and clinical expression between genders and between prepubertal and adolescent-onset cases. Findings of this study supported the introduction of tic-related OCD as a specifier in Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-5), and the necessity of a detailed assessment of other psychiatric disorders in youth with OCD.

Tic-Related Obsessive-Compulsive Disorder (OCD): Phenomenology and Treatment Outcome in the Pediatric OCD Treatment Study II

Prior research has shown that youth with co-occurring tic disorders and obsessive-compulsive disorder (OCD) may differ from those with non-tic-related OCD in terms of clinical characteristics and treatment responsiveness. A broad definition of "tic-related" was used to examine whether children with tics in the Pediatric OCD Treatment Study II differed from those without tics in terms of demographic and phenomenological characteristics and acute treatment outcomes. Participants were 124 youth aged 7 to 17 years, inclusive, with a primary diagnosis of OCD who were partial responders to an adequate serotonin reuptake inhibitor (SRI) trial. Participants were randomized to medication management, medication management plus instructions in cognitive-behavioral therapy (CBT), or medication management plus full CBT. Tic status was based on the presence of motor and/or vocal tics on the Yale Global Tic Severity Scale. Tics were identified in 53% of the sample. Those with tic-related OCD did not differ from those with non-tic-related OCD in terms of age, family history of tics, OCD severity, OCD-related impairment, or comorbidity. Those with tics responded equally in all treatment conditions. Tic-related OCD was very prevalent using a broad definition of tic status. Results suggest that youth with this broad definition of tic-related OCD do not have increased OCD severity or inference, higher comorbidity rates or severity, or worsened functioning, and support the use of CBT in this population. This highlights the importance of not making broad assumptions about OCD symptoms most likely to occur in an individual with comorbid tics. Clinical trial registration information-Treatment of Pediatric OCD for SRI Partial Responders; http://clinicaltrials.gov; NCT00074815.

Antipsychotic augmentation of selective serotonin reuptake inhibitors in resistant tic-related obsessive-compulsive disorder in children and adolescents: A naturalistic comparative study

The aim of this study is to assess efficacy of augmentation of SSRIs with risperidone or aripiprazole in youths with tic-related Obsessive-Compulsive Disorder (OCD) non responders to an SSRI monotherapy. 120 consecutive patients (age range 7–18 years) were treated with an SSRI monotherapy for at least 12 weeks, 51 (42.5%) were responders, and the 69 non-responders (mean age 13.7 ± 2.4 years) were included in this study. 35 patients received an augmentation with risperidone (1.7 ± .8 mg/day), and 34 with aripiprazole (8.9 ± 3.1 mg/day) for 12 weeks. Regarding the OCD symptomatology, at the endpoint the Clinical Global Impression-Severity score (CGI-S) improved from 5.6 ± .8 (severely ill), to 3.2 ± .9 (mild to moderately ill) (p < .0001), and the Children-Global Assessment Scale (C-GAS) from 40.3 ± 5.2 to 53.8 ± 9.2 (p < .0001). Thirty-nine patients (56.5%) were responders in OCD symptomatology (CGI-I score 1 or 2, CGI-S score 3 or less and C-GAS score 50 or more during three consecutive months after a 12-week treatment). Compared to non responders, they were less impaired at the baseline in CGI-S (p < .0001) and C-GAS (p < .0001). Subtypes of OCD and comorbidity did not affect the response. No differences were found between risperidone and aripiprazole augmentation. 47 patients (68.1%) significantly improved tics, without differences between risperidone and aripiprazole. None discontinued medications because of side effects, but risperidone was associated with weight gain and sedation, and aripiprazole to mild/moderate agitation. In tic-related pediatric OCD, augmentation of SSRIs with risperidone or aripiprazole was tolerated and effective in about half of the patients non responding to an SSRI.

1555 – Repetitive behaviors in tourette syndrome

Introduction In Tourette Syndrome (TS), a neuropsychiatric disorder, tics are frequently associated with obsessivecompulsive symptoms that not always fulfill criteria for Obsessive- Compulsive Disorder (OCD). Phenomenological, genetic and epidemiologic studies suggest a strong association between TS and OCD, not only in patients but also in their relatives. Obsessive-compulsive symptoms can be found in 28-63% of TS patients. Motor portions of cortico-striato-thalamic-cortical circuits are implicated in tics and compulsions. Integrating these repetitive behaviors in Obsessive-Compulsive (OC) spectrum, a continuum between Compulsion and Impulsion, OCD tic-free is positioned at the compulsive end and tic-related OCD and ST are positioned between the two poles. Objectives This communication has as main objective to characterize the repetitive behaviors in TS by presenting the differences and similarities with compulsions. Aims To integrate TS in OC spectrum. Methods Articles’ selection in PUBMED and SCIENCEDIRECT databases and literature’s review about the theme. Results According to clinical features and treatment response, tic-related OCD has an intermediate position between OCD ticfree and TS, sharing common aspects with both entities. Conclusions TS may be differenciated from OCD subgroups, namely tic-related OCD, by its clinical features and therapeutic response. The presence of repetitive touching actions and ecophenomena seems to discriminate TS from OCD. The phenomenological characterization of repetitive behaviors in TS is extremely important, as tic and compulsion’s treatment is different.

Error-Related Negativity and Tic History in Pediatric Obsessive-Compulsive Disorder

The error-related negativity (ERN) is a negative deflection in the event-related potential after an incorrect response, which is often increased in patients with obsessive-compulsive disorder (OCD). However, the relation of the ERN to comorbid tic disorders has not been examined in patients with OCD. This study compared ERN amplitudes in patients with tic-related OCD, patients with non-tic-related OCD, and healthy controls. The ERN, correct response negativity, and error number were measured during an Eriksen flanker task to assess performance monitoring in 44 youth with a lifetime diagnosis of OCD and 44 matched healthy controls ranging in age from 10 to 19 years. Nine youth with OCD had a lifetime history of tics. ERN amplitude was significantly increased in patients with OCD compared with healthy controls. ERN amplitude was significantly larger in patients with non-tic-related OCD than in patients with tic-related OCD or controls. ERN amplitude had a significant negative correlation with age in healthy controls but not in patients with OCD. Instead, in patients with non-tic-related OCD, ERN amplitude had a significant positive correlation with age at onset of OCD symptoms. ERN amplitude in patients was unrelated to OCD symptom severity, current diagnostic status, or treatment effects. The results provide further evidence of increased error-related brain activity in pediatric OCD. The difference in the ERN between patients with tic-related and those with non-tic-related OCD provides preliminary evidence of a neurobiological difference between these two OCD subtypes. The results indicate the ERN is a trait-like measurement that may serve as a biomarker for non-tic-related OCD.

Error-Related Negativity and Tic History in Pediatric Obsessive-Compulsive Disorder

Objective: The error-related negativity (ERN) is a negative deflection in the event-related potential after an incorrect response, which is often increased in patients with obsessivecompulsive disorder (OCD). However, the relation of the ERN to comorbid tic disorders has not been examined in patients with OCD. This study compared ERN amplitudes in patients with tic-related OCD, patients with non‐tic-related OCD, and healthy controls. Method: The ERN, correct response negativity, and error number were measured during an Eriksen flanker task to assess performance monitoring in 44 youth with a lifetime diagnosis of OCD and 44 matched healthy controls ranging in age from 10 to 19 years. Nine youth with OCD had a lifetime history of tics. Results: ERN amplitude was significantly increased in patients with OCD compared with healthy controls. ERN amplitude was significantly larger in patients with non‐tic-related OCD than in patients with tic-related OCD or controls. ERN amplitude had a significant negative correlation with age in healthy controls but not in patients with OCD. Instead, in patients with non‐tic-related OCD, ERN amplitude had a significant positive correlation with age at onset of OCD symptoms. ERN amplitude in patients was unrelated to OCD symptom severity, current diagnostic status, or treatment effects. Conclusions: The results provide further evidence of increased error-related brain activity in pediatric OCD. The difference in the ERN between patients with tic-related and those with non‐tic-related OCD provides preliminary evidence of a neurobiological difference between these two OCD subtypes. The results indicate the ERN is a trait-like measurement that may serve as a biomarker for non‐tic-related OCD. J. Am. Acad. Child Adolesc. Psychiatry, 2012;51(9):902‐910. Key Words: anxiety disorder, tic disorder, brain potential, performance monitoring, biomarker

Clinical features of tic-related obsessive-compulsive disorder: results from a large multicenter study

To evaluate the clinical features of obsessive-compulsive disorder (OCD) patients with comorbid tic disorders (TD) in a large, multicenter, clinical sample. A cross-sectional study was conducted that included 813 consecutive OCD outpatients from the Brazilian OCD Research Consortium and used several instruments of assessment, including the Yale-Brown Obsessive-Compulsive Scale, the Dimensional Yale-Brown Obsessive-Compulsive Scale, the Yale Global Tic Severity Scale (YGTSS), the USP Sensory Phenomena Scale, and the Structured Clinical Interview for DSM-IV Axis I Disorders. The sample mean current age was 34.9 years old (SE 0.54), and the mean age at obsessive-compulsive symptoms (OCS) onset was 12.8 years old (SE 0.27). Sensory phenomena were reported by 585 individuals (72% of the sample). The general lifetime prevalence of TD was 29.0% (n = 236), with 8.9% (n = 72) presenting Tourette syndrome, 17.3% (n = 141) chronic motor tic disorder, and 2.8% (n = 23) chronic vocal tic disorder. The mean tic severity score, according to the YGTSS, was 27.2 (SE 1.4) in the OCD + TD group. Compared to OCD patients without comorbid TD, those with TD (OCD + TD group, n = 236) were more likely to be males (49.2% vs. 38.5%, p < .005) and to present sensory phenomena and comorbidity with anxiety disorders in general: separation anxiety disorder, social phobia, specific phobia, generalized anxiety disorder, post-traumatic stress disorder, attention-deficit hyperactivity disorder, impulse control disorders in general, and skin picking. Also, the "aggressive," "sexual/religious," and "hoarding" symptom dimensions were more severe in the OCD + TD group. Tic-related OCD may constitute a particular subgroup of the disorder with specific phenotypical characteristics, but its neurobiological underpinnings remain to be fully disentangled.

Impaired Sensorimotor Gating in Unmedicated Adults with Obsessive–Compulsive Disorder

Functional and structural imaging studies suggest that obsessive-compulsive disorder (OCD) symptoms arise from dysfunction in cortico-striato-thalamo-cortical circuits. It has therefore been hypothesized that neurophysiological tasks subserved by these circuits should be abnormal in OCD patients. One neurocognitive probe associated with this circuitry is prepulse inhibition (PPI) of the acoustic startle response. PPI deficits are thought to reflect abnormalities in processing and integration of sensory and motor information. Two prior studies found that OCD patients had PPI deficits at single prepulse (PP) intensities. However, most patients in these studies were taking psychotropic medications at the time of PPI testing, and preclinical studies have demonstrated effects of psychotropic medications on PPI. We examined PPI in 22 unmedicated OCD patients and 22 matched healthy controls at three different PP intensities (74, 78, and 86 dB). OCD patients had significantly less PPI across all three PP intensities compared with controls. Exploratory analyses indicated that OCD patients with a history of tics had lower levels of PPI. Our results demonstrate that unmedicated OCD patients have impaired sensorimotor gating as measured by PPI. This indicates that PPI deficits are present in OCD patients and are not the result of medication effects. Our findings also suggest that OCD patients with a history of tics may have greater impairment in sensorimotor gating than the general OCD population. Future studies should be designed to examine whether PPI deficits characterize tic-related OCD.

Cerebellar morphology in Tourette syndrome and obsessive‐compulsive disorder

Neuroanatomical and functional imaging studies have identified the cerebellum as an integral component of motor and language control. Few studies, however, have investigated the role of the cerebellum in Tourette syndrome (TS), a condition defined by the presence of semi-involuntary movements and sounds. Magnetic resonance imaging was conducted in 163 persons with TS and 147 control participants. Multivariate linear regression models were used to explore effects on cerebellar surface morphology and underlying volumes for the main diagnosis effects of TS as well as comorbid obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder. Additionally, the correlations of symptom severity with cerebellar morphology were also assessed. The TS group demonstrated reduced volumes of the cerebellar hemispheres bilaterally that derived primarily from reduced gray matter in crus I and lobules VI, VIIB, and VIIIA. These decreased regional volumes accompanied increasing tic symptom severity and motoric disinhibition as demonstrated by a finger tapping test. Males had reduced volumes of these same regions compared with females, irrespective of diagnosis. Comorbid OCD was associated with relative enlargement of these regions in proportion to the increasing severity of OCD symptoms. The cerebellum is involved in the pathogenesis of TS and tic-related OCD. Baseline gender differences in cerebellar morphology may in part account for the more prevalent expression of TS in males.