Long term clinical course of Tourette syndrome

Correlation of Comorbidities and Variability of Tics in Children with Chronic Tic Disorder

OBJECTIVE

 Chronic tic disorder (CTD) is characterized by the presence of motor and/or phonic tics, and is often accompanied by comorbidities, where obsessive-compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) are the most predominant. The aim of this study was to investigate a correlation between comorbidities and variability of tics in children with CTD.

METHOD

 A cross-sectional study was completed on a clinical cohort recruited from the Danish National Tourette Clinic at Herlev Hospital. The cohort consisted of 167 children who were examined by the Yale Global Tic Severity Scale. Data regarding comorbidity were collected on 152 of these patients by using validated diagnostic instruments, and the patients were divided into four subgroups: CTD-only, CTD + ADHD, CTD + OCD, and CTD + ADHD + OCD.

RESULTS

 The comorbidity subgroups had significantly higher severity, impairment, and Total Tic Scores compared to the CTD-only group (p-value ≤ 0.001, 0.001, 0.003, respectively). The assessment of the association between variability of tics and comorbidities showed a significantly higher Simple Phonic Tic Score in the CTD + OCD group compared to the CTD-only group (p-value = 0.003).

CONCLUSION

 This study showed significantly higher Simple Phonic Tic Scores in the CTD + OCD group compared to the CTD-only group, which suggests that awareness of the variability of tics in patients with CTD and comorbidities is important.Total Tic Scores, severity of tics, and impairment were significantly higher in the comorbidity subgroups compared to the CTD-only group, which support findings from previous studies.

Development and validation of a nomogram prediction model for ADHD in children based on individual, family, and social factors

OBJECTIVES

A reliable, user-friendly, and multidimensional prediction tool can help to identify children at high risk for ADHD and facilitate early recognition and family management of ADHD. We aimed to develop and validate a risk nomogram for ADHD in children aged 3-17 years in the United States based on clinical manifestations and complex environments.

METHODS

A total of 141,356 cases were collected for the prediction model. Another 54,444 cases from a new data set were utilized for performing independent external validation. The LASSO regression was used to control possible variables. A final risk nomogram for ADHD was established based on logistic regression, and the discrimination and calibration of the established nomogram were evaluated by bootstrapping with 1000 resamples.

RESULTS

A final risk nomogram for ADHD was established based on 13 independent predictors, including behavioral problems, learning disabilities, age, intellectual disabilities, anxiety symptoms, gender, premature birth, maternal age at childbirth, parent-child interaction patterns, etc. The C-index of this model was 0.887 in the training set, and 0.862 in the validation set. Internal and external validation proved that the model was reliable.

CONCLUSIONS

A nomogram, a statistical prediction tool that assesses individualized ADHD risk for children is helpful for the early identification of children at high risk for ADHD and the construction of a conceptual model of society-family-school collaborative diagnosis, treatment, and management of ADHD.

A Critical Examination of the Clinical Diagnosis of Functional Tic-like Behaviors

BACKGROUND

Since the COVID-19 pandemic, movement disorder clinics have seen an increase in patients with an unusual type of tic-like symptoms: young adults with abrupt onset complex behaviors. It was quickly suspected that these patients suffered from functional neurological symptoms, later named Functional Tic-Like Behaviors (FTLB). Subsequent research on the differential diagnosis between FTLB and tics has been substantial and led to the development of diagnostic checklists.

OBJECTIVES

We conducted a theoretical reappraisal of the FTLB literature to clarify the validity of the concept and its diagnostic implications.

METHODS

This paper addresses several key aspects of the current FTLB literature: circular reasoning, the complications of the FTLB phenomenology and demographics, the impact of FTLB on tic literature at large, and issues with alignment of the FTLB concept with the diagnostic criteria for functional disorders.

RESULTS

The clinical approach to FTLB might involve circular reasoning due to a lack of clinical benchmarks. The FTLB phenomenology and demographics may need more work to ensure a lack of bias and a proper description of this patient group including a clear distinction from tics. The impact of the FTLB discussion on the wider literature needs consideration. The validation of positive signs may help with both these endeavors and pave way to the inclusion of FTLB within psychiatric classification systems. Furthermore, the coexistence of FTLB and tics within the same patient needs to be addressed.

CONCLUSION

More research may be needed to fully establish the diagnosis of FTLB and differentiate it from tics.

Comorbidities and Disease Duration in Tourette Syndrome: Impact on Cognition and Quality of Life of Children

BACKGROUND

Cognitive functions represent foundational factors for mental health and quality of life (QoL). In Tourette syndrome (TS), psychiatric comorbidities are common and have been inconsistently reported to affect the cognition and QoL of patients, while the role of tic disorder duration has not been yet explored.

METHODS

To examine how comorbidities and TS duration may influence cognition and QoL, N = 80 children with TS (6-16 years) were evaluated using the Wechsler Intelligence Scale for Children (WISC-IV). Standardized questionnaires were used to assess the presence and severity of TS main comorbidities and QoL. Data were interpreted using linear correlations, regression, and mediation analysis.

RESULTS

Depression and attention-deficit/hyperactivity disorder (ADHD) symptoms accounted for poorer cognitive performance. Anxiety oppositely predicted better cognitive performance, while no significant role for obsessive compulsive disorder (OCD) was observed. Disease duration was associated with lower total IQ, verbal reasoning, and working memory abilities. Depression, anxiety, and TS duration also deeply influenced QoL measures.

CONCLUSIONS

TS common comorbidities have a differential impact on the cognitive abilities of children and adolescents, which translates into a complex influence on their perceived QoL. A longer clinical history of tics was related to worse cognitive outcomes, which prompts further consideration of disease duration in both clinical and research settings involving children and adolescents.

Where Do Neurodevelopmental Disorders Go? Casting the Eye Away from Childhood towards Adulthood

Neurodevelopmental disorders (NDDs) encompass a group of complex conditions with onset during the early developmental period. Such disorders are frequently associated with a number of neuropsychiatric features, the most prevalent ones being autism spectrum disorder, attention-deficit/hyperactivity disorder, intellectual disability, communication and specific learning disorders, and motor disorders. These conditions are characterized by wide genetic and clinical variability, and although they were previously conceptualized as childhood-limited disorders, NDDs are progressively being recognized as persistent conditions with a potentially relevant impact on the quality of life and overall functioning during adult life. In addition, emerging evidence seems to point towards the hypothesis of a neurodevelopmental continuum, according to which NNDs could portray different time-dependent outcomes, depending on the severity of the altered brain development. Despite representing lifelong phenotypes, they are often not promptly identified and/or managed in adulthood. In this regard, specific guidelines on clinical and therapeutic approaches for these conditions have not yet been delineated. In this view, future research investigations should be encouraged to broaden available knowledge, characterize the clinical course of NDDs across an individual’s lifespan, and better understand the patterns of aging-related concerns in adults with an NDD diagnosis. Additionally, considering the difficulties many young adults encounter while transitioning from childhood to adult mental health services, new, specific programs should be developed and existing programs should be implemented to improve the transition process and for the management of NDDs in adulthood.

The hidden link between circadian entropy and mental health disorders

The high overlapping nature of various features across multiple mental health disorders suggests the existence of common psychopathology factor(s) (p-factors) that mediate similar phenotypic presentations across distinct but relatable disorders. In this perspective, we argue that circadian rhythm disruption (CRD) is a common underlying p-factor that bridges across mental health disorders within their age and sex contexts. We present and analyze evidence from the literature for the critical roles circadian rhythmicity plays in regulating mental, emotional, and behavioral functions throughout the lifespan. A review of the literature shows that coarse CRD, such as sleep disruption, is prevalent in all mental health disorders at the level of etiological and pathophysiological mechanisms and clinical phenotypical manifestations. Finally, we discuss the subtle interplay of CRD with sex in relation to these disorders across different stages of life. Our perspective highlights the need to shift investigations towards molecular levels, for instance, by using spatiotemporal circadian "omic" studies in animal models to identify the complex and causal relationships between CRD and mental health disorders.

Tourette syndrome in children: An update

Tourette syndrome (TS) causes academic, social, emotional, physical, and functional problems. Most TS patients also have comorbid neuropsychological conditions. The purpose of this review is to provide updated information to the clinician about phenomenology, epidemiology, comorbidities, pathophysiology and management strategies for tics (a hallmark of TS) and TS. Recent findings suggest that TS is likely due to a combination of several different genes and environmental factors, with possible involvement of the cortical-basal ganglia-thalamocortical circuit and related multiple neurotransmitters. First-line management includes psychoeducation for families, patients, and school personnel, as well as behavioral therapy. Non-medicine treatment for tics is advancing to include younger children and increase access via remote service applications. Pharmacotherapy is used if appropriate and several new medicines are under investigation (e.g., Tetrabenazine, valbenazine, deutetrabenazine, ecopipam, cannabinoids). Deep brain stimulation and Mouthguard therapy can be used for children with intractable illness.

An International Survey of Health Care Services Available to Patients With Tourette Syndrome

Objective: Tourette syndrome (TS) is a neuropsychiatric disorder that is highly associated with several comorbidities. Given the complex and multifaceted nature of TS, the condition is managed by a wide variety of practitioners in different disciplines. The goal of this study was to investigate health service delivery and care practices by clinicians who see TS patients across different geographic settings internationally. Methods: A comprehensive questionnaire was developed to assess clinical care resources for patients with TS and was sent to clinicians in Canada (CA), the United States (US), Europe (EU), and the United Kingdom (UK). Responses were compared quantitatively between geographic regions. Results: The majority of respondents, regardless of region, reported that fewer than 40% of their case-load are patients with tics. The accessibility of TS services varied among regions, as indicated by differences in wait times, telemedicine offerings, comorbidity management and the availability of behavioral therapies. First-line pharmacotherapy preferences varied among physicians in different geographical regions with CA respondents preferring alpha-2-adrenergic agonists and respondents from the UK and EU preferring dopamine receptor antagonists. Discussion: The results suggest that there is a scarcity of specialized TS clinics, potentially making access to services challenging, especially for patients newly diagnosed with TS. Differences in regional pharmacotherapeutic preferences are reflected in various published treatment guidelines in EU and North America. The lack of dedicated specialists and telemedicine availability, coupled with differences in comorbidity management, highlight the need for interprofessional care and holistic management to improve health care delivery to patients with TS.

Clinical Correlates of Health-Related Quality of Life in Adults With Chronic Tic Disorder

Tics are the hallmark feature of Tourette syndrome (TS), but psychiatric and sensory symptoms are widely prevalent and increasingly recognized as core manifestations of the disorder. Accumulating evidence suggests that these psychiatric and sensory symptoms exert greater influence on quality of life (QOL) than tics themselves. However, much remains uncertain about determinants of QOL in TS due to the complexity of the clinical presentation. Here, we sought to clarify the association between health-related QOL (HRQOL) and common psychiatric and sensory symptoms in adults with TS and other chronic tic disorders. To do so, we prospectively recruited 52 patients from a tertiary care clinic to complete self-report measures assessing HRQOL (Gilles de la Tourette-Quality of Life Scale, GTS-QOL), depression (Patient Health Questionnaire-9, PHQ-9), anxiety (Generalized Anxiety Disorder Scale-7, GAD-7), obsessive-compulsive symptoms (Dimensional Obsessive-Compulsive Scale, DOCS), attention deficit hyperactivity disorder symptoms (Adult ADHD Self-Report Screening Scale for DSM-5, ASRS-V), and premonitory urge (Premonitory Urge to Tic Scale, PUTS). All participants were also administered the Yale Global Tic Severity Scale (YGTSS) to quantify tic severity. Using correlational analysis and multivariable linear regression modeling, we found that GTS-QOL score was significantly associated with scores from all other rating scales, with the exception of the PUTS. GTS-QOL was most strongly associated with PHQ-9, followed by ASRS-V, GAD-7, DOCS, and YGTSS total tic score. The regression model including these five independent variables, as well as sex, explained 79% of GTS-QOL score variance [F _(6,40) = 29.6, p < 0.001]. Specific psychiatric symptoms differentially impacted physical, psychological, and cognitive HRQOL. Systematic assessment of psychiatric comorbidities is imperative for clinical care and clinical research efforts directed at improving QOL in adults with chronic tic disorders.

Incidence of Autism Spectrum Disorder in Youths Affected by Gilles de la Tourette Syndrome Based on Data from a Large Single Italian Clinical Cohort

Gilles de la Tourette syndrome (GTS) and autism spectrum disorder (ASD) are etiologically related neurodevelopmental disorders with an onset age before 18 years and a reported comorbidity of 2.9–20%. The aim of the present study was to identify the incidence of ASD in a large clinical sample of individuals affected by GTS and to compare our results with previously reported incidences. We retrospectively analyzed clinical data (n = 1200) from January 2010 to March 2019 obtained from the outpatient Catania Tourette Clinic, part of the Child and Adolescent Neurology and Psychiatry of the Medical and Experimental Department of Catania University. We used internationally validated evaluation tools. The neuropsychological evaluation was carried out by an expert and a certificated team of child and adolescent neurologists, supervised by two expert child neurologists (R.R. and M.G.). We investigated 975 GTS-affected individuals of various socioeconomic levels aged 5–18 years, and 8.9% (n = 87) were affected by ASD. The incidence of GTS with ASD was significantly lower (p < 0.001) in children than in adolescents. No statistically significant differences were found in the sex distribution and age of onset of tics between individuals with GTS alone and those with GTS and ASD. The incidence of GTS and ASD comorbidity in this study was high, and this has several implications in terms of treatment and prognosis.

Rage attacks in Tourette Syndrome and Chronic Tic Disorder: a systematic review

Tourette syndrome (TS) and chronic motor/vocal tic disorder (CTD) are neurodevelopmental conditions defined by the occurrence of multiple tics. Besides the well-known association with attention deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD), rage attacks (RA) represent common and detrimental symptoms for patients. Inorder to explore prevalence of RA in tic disorders, relation to tic severity/comorbidities and available treatments, we performed a systematic literature review based on PRISMA Guidelines. 32 studies published between January 2008 - December 2019 were deemed suitable for the analysis and provided a prevalence of 20-67 %. Most findings showed a direct correlation with tic severity and a significant impact on psychosocial functioning. Although apparently related to comorbid ADHD, RA also frequently occur as independent manifestations. Association with other comorbidities, such as OCD, impulse control and mood disorders has also been reported, not yet fully established. Behavioral interventions appear to be effective, whereas there is limited evidence concerning the efficacy of medication. In TS/CTD, RA may be regarded as a major comorbidity that requires clinical investigation in order to develop personalized treatments.

Clinical Features of Tourette Syndrome

Tourette syndrome is a multifaceted disorder characterized by multiple motor and at least one vocal tics that start in childhood, persist for at least 1 year, and cannot be attributed to another medical condition or exposure to medications/drugs. Clinical diagnostic criteria are available, and identification of tics is typically straightforward based on characteristic appearance and features. Diagnostic uncertainty can rarely arise in cases of mild tics, atypical features, certain psychiatric comorbidities, and other non-tic movement disorders. Comorbid psychopathology, including attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive behaviors/obsessive-compulsive disorder, affects the majority of patients and is correlated with disease severity and the presence of additional psychiatric behaviors. The severity of tics often improves after adolescence, whereas psychiatric symptoms typically persist. The subset of patients in whom tics persist into adulthood experience higher rates of anxiety, and lower self-esteem, socioeconomic status, and quality of life; the relative contribution of motor tics and psychopathology is not fully understood. This article summarizes the clinical features of Tourette syndrome, including major diagnostic criteria, unique features of tics, and key aspects that differentiate tics from common mimics and chameleons. Comorbid psychiatric conditions and their impact on phenotype and quality of life are described. Finally, current understanding of the natural history is summarized, including limited research in adults with Tourette syndrome.

Treatment options for tic disorders

Introduction: Gilles de la Tourette syndrome (GTS) is a neurodevelopmental disorder, characterized by the presence of multiple motor and, at least one, phonic tics, for more than one year, beginning before 18 years of age; its treatment is often a challenge for the clinicianAreas covered: GTS treatment requires a multidisciplinary management to treat each patient's symptom. Although individuals with GTS often have comorbid psychiatric disorders, the focus of this review will only be on the management of tics.Expert opinion: The authors summarized the steps that clinicians should follow treating GTS patient; the impact of the tics on a patients' life should be the first step; different patients could present different levels of tolerance to the symptoms. Second, comorbidities should be considered before starting a treatment for tic. Finally, clinicians must focus the attention of the patient and family, on the length of the treatment and the duration of time after which the effects of the drug will occur. Before the treatment, the potential side effects must be mentioned to the parents, and the choice of treatment must be made in the light of the patient's tolerance to these.

The effects of comorbid Tourette symptoms on distress caused by compulsive-like behavior in very young children: a cross-sectional study

BACKGROUND

Many children 4 to 6 years old exhibit compulsive-like behavior, often with comorbid Tourette symptoms, making this age group critical for investigating the effects of having comorbid Tourette symptoms with compulsive-like behavior. However, these effects have not yet been elucidated: it is unclear whether having comorbid tics with compulsive-like behavior leads to lower quality of life. This cross-sectional study aims to investigate the effect of comorbid Tourette symptoms on distress caused by compulsive-like behavior in very young children.

METHODS

Self-administered questionnaires were distributed to guardians of children aged 4 to 6 attending any of the 59 public preschools in a certain ward in Tokyo, Japan. The questionnaire contained questions on the presence of Tourette symptoms, the presence of specific motor and vocal tics, frequency/intensity of compulsive-like behavior, and the distress caused by compulsive-like behavior, which was rated on a scale of 1 to 5. Additionally, questions on autism spectrum disorder (ASD) traits, attention-deficit/hyperactivity disorder (ADHD) traits, internalizing behavior traits, and externalizing behavior traits were included in the questionnaire as possible confounders of distress caused by compulsive-like behavior. Wilcoxon rank-sum tests were conducted to compare the distress caused by compulsive-like behavior and frequency/intensity of compulsive-like behavior between children in the Tourette symptoms group and the non-Tourette symptoms group. Furthermore, a stepwise regression analysis was performed to assess the effects of the independent variables on distress caused by compulsive-like behavior. Another stepwise regression analysis was performed to assess the relationship between distress caused by compulsive-like behavior and the presence of five specific motor and vocal tics.

RESULTS

Of the 675 eligible participants, distress due to compulsive-like behavior was significantly higher in children in the Tourette symptoms group compared to the non-Tourette symptoms group (2.00 vs 1.00, P < 0.001). Stepwise regression analysis showed that frequency/intensity of compulsive-like behavior, being in the Tourette symptoms group, ASD traits, and internalizing behavior traits were predictors of distress due to compulsive-like behavior. Two specific tics, repetitive noises and sounds and repetitive neck, shoulder, or trunk movements, were significant predictors of distress due to compulsive-like behavior.

CONCLUSIONS

Comorbid Tourette symptoms may worsen distress caused by compulsive-like behavior in children 4 to 6 years old, and specific motor and vocal tics may lead to greater distress.

The impact of attention deficit hyperactivity disorder in obsessive-compulsive disorder subjects

BACKGROUND

Recent findings suggest an association between attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). Thus, we evaluated the clinical associated features of ADHD in a large sample of adult OCD patients.

METHODS

A cross-sectional study including 955 adult patients with OCD from the Brazilian Research Consortium of Obsessive-Compulsive Spectrum Disorders (C-TOC). Clinical characteristics in adult OCD patients with and without comorbid ADHD were compared using Fisher's exact test, t-tests or Mann-Whitney tests. Bivariate analyses were followed by logistic regression analysis to identify clinical characteristics independently associated with ADHD comorbidity.

RESULTS

The lifetime prevalence of ADHD in adult OCD patients was 13.7%. The current results indicate that OCD + ADHD patients were more severe, had an earlier onset of the obsessive-compulsive symptoms, a higher history of rheumatic fever, with higher frequencies of sensory phenomena and comorbidity with Tourette syndrome. They also had an increased risk for academic impairment and suicide attempts.

CONCLUSION

Adult OCD patients with ADHD present some specific clinical features and may represent a special subgroup of adult OCD. Future studies should focus on the development of interventions more tailored to the phenotype of this subgroup of patients.

Oppositional behavior and longitudinal predictions of early adulthood mental health problems in chronic tic disorders

Chronic tic disorders (TD) are associated with a number of psychological problems such as attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive behavior (OCB), oppositional-defiant disorder (ODD) as well as anxious and depressive symptoms. ODD is often considered a risk factor for many psychological symptoms and recent work suggests that different ODD dimensions show independent predictions of later psychological problems. This study examined the longitudinal predictions between ODD dimensions of Irritability and Defiance and the most frequent comorbidities in TD from childhood to early adulthood. From an initial sample of 135, parent reports were obtained on 58 participants with TD using standard clinical questionnaires and semi-structured interviews. Defiance symptoms decreased from baseline to follow-up whereas Irritability symptoms were more stable over time. In multiple regressions, Irritability in childhood predicted anxiety and OCB in early adulthood while Defiance in childhood predicted ADHD and conduct disorder symptoms in early adulthood. No developmental link was found for depressive symptoms. Results indicate that ODD dimensions are developmentally linked to both internalizing and externalizing adult mental health symptoms in TD.

Tourette’s syndrome and its borderland

The Gilles de la Tourette syndrome (or Tourette’s syndrome) has a prevalence of 1% of children with a wide range of severity and associated comorbidities. The last 20 years have seen advances in the understanding of the syndrome’s complex genetics and underlying neurobiology. Investigation with imaging and neurophysiology techniques indicate it is a neurodevelopmental condition with dysfunction of basal ganglia–cortical interactions, which are now also being studied in animal models. There is also increasing evidence for treatments although it often remains difficult to manage. First-line options include neuroleptics, other drugs and specialised behavioural treatments. Deep brain stimulation is an evolving field, not yet fully established. This review focuses on the phenomenology of tics, how to assess and manage the syndrome, and uses examples of atypical cases to explore the characteristics and limits of its clinical spectrum.

Executive control development in Tourette syndrome and its role in tic reduction

Tourette syndrome (TS) is a childhood-onset disorder characterized by motor and vocal tics. Recent findings point to a possible role of executive functions system development in the tic reduction observed with age. The goal of the present work was to track the development of executive functions system measured by well-established cognitive tasks and its correlation with diminished tic severity over time in order to understand the role of executive functions in the remission process observed in most adults. The first study followed 25 young TS patients, measuring their executive functions and clinical condition at three time- points. In the second study we compared executive functions performance of 19 adult TS patients with 19 healthy controls and 12 remitted TS patients. The first study showed that tic reduction is related to the development of the executive functions components associated with response inhibition. The second study similarly showed impaired inhibition ability in TS patients but not in controls or the remitted TS patients. The remitted group performed at normal or even higher levels on certain measures. We conclude that inhibition, an important executive function, is impaired in subjects suffering from TS and that intact executive function development is related to remission processes.

Tic Disorders and PANDAS

Tics are the most common movement disorder in childhood and are a frequent reason for referral to child neurology clinics. The purpose of this review is to examine the phenomenology of tics, discuss what is known regarding their genetic and pathophysiological causes and to evaluate current treatment options. The evidence for the evaluation and treatment of the controversial diagnosis of pediatric autoimmune neuropsychiatric disorders associated with group A streptococci (PANDAS) will also be reviewed. With improved understanding of tic disorders, their etiology and response to current treatment options, we may be able to more effectively diagnose them and identify novel treatment strategies.

Phenotype Development in Adolescents With Tourette Syndrome: A Large Clinical Longitudinal Study

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by frequent comorbidities and a wide spectrum of phenotype presentations. This study aimed to describe the development of phenotypes in TS and tic-related impairment in a large longitudinal study of 226 children and adolescents followed up after 6 years. The participants were clinically examined to assess tic severity and impairment, obsessive compulsive disorder (OCD), and attention-deficit/hyperactivity disorder (ADHD). The development in phenotypes changed toward less comorbidity with 40% TS-only (no OCD or ADHD) (TS without OCD or ADHD) at baseline and 55% at follow-up.Tic-related impairment was expected to improve with an age-related tic decline, but surprisingly the impairment score did not reflect the tic decline. Sex, vocal and motor tics, and OCD and ADHD severity were highly significantly correlated to the impairment score. Knowledge of TS phenotype development is used in clinical settings to guide patients and for genetic, etiological, and clinical research purposes.

Progress in Genetic Studies of Tourette's Syndrome

Tourette's Syndrome (TS) is a complex disorder characterized by repetitive, sudden, and involuntary movements or vocalizations, called tics. Tics usually appear in childhood, and their severity varies over time. In addition to frequent tics, people with TS are at risk for associated problems including attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), anxiety, depression, and problems with sleep. TS occurs in most populations and ethnic groups worldwide, and it is more common in males than in females. Previous family and twin studies have shown that the majority of cases of TS are inherited. TS was previously thought to have an autosomal dominant pattern of inheritance. However, several decades of research have shown that this is unlikely the case. Instead TS most likely results from a variety of genetic and environmental factors, not changes in a single gene. In the past decade, there has been a rapid development of innovative genetic technologies and methodologies, as well as significant progresses in genetic studies of psychiatric disorders. In this review, we will briefly summarize previous genetic epidemiological studies of TS and related disorders. We will also review previous genetic studies based on genome-wide linkage analyses and candidate gene association studies to comment on problems of previous methodological and strategic issues. Our main purpose for this review will be to summarize the new genetic discoveries of TS based on novel genetic methods and strategies, such as genome-wide association studies (GWASs), whole exome sequencing (WES) and whole genome sequencing (WGS). We will also compare the new genetic discoveries of TS with other major psychiatric disorders in order to understand the current status of TS genetics and its relationship with other psychiatric disorders.

Psychiatric comorbidities in movement disorders

Psychiatric comorbidities are common in movement disorders. This review provides a practical approach to help clinicians to recognize psychiatric disorders in the most frequent movement disorders. However, the extent of neurodegeneration, as well as the impact of medications with considerable CNS effects, influences the diverse psychiatric presentations that, in turn, are influenced by the stress of living with a movement disorder. Depression, anxiety, and psychosis are the most common psychiatric comorbidities in movement disorders and of the medications used to treat the motor disturbances. These psychiatric problems impair patients' functioning throughout the course of the chronic neurodegenerative diseases. Due to the direct connection between brain dysfunction and psychiatric symptoms, there is hope that understanding the psychiatric comorbidities in movement disorders will lead to a better quality-of-life.

Health-related quality of life, anxiety and depression in parents of adolescents with Gilles de la Tourette syndrome: a controlled study

Our objectives were to assess health-related quality of life (HRQoL), anxiety, depression of Gilles de la Tourette syndrome (GTS) adolescents' parents compared to controls; to assess GTS adolescents' HRQoL compared to controls; to investigate which parental and adolescent variables are associated with poorer parental HRQoL. The controlled study involved GTS outpatients and their parents, adolescent healthy controls matched for gender and age and their parents. Parents' HRQoL was assessed using SF-36 and WHOQOL-BREF; anxiety, depression using HADS. Adolescents' HRQoL was assessed by adolescents using VSP-A instrument and by their parents using VSP-P. A total of 75 GTS adolescents, 75 mothers, 63 fathers were compared to 75 control adolescents, 75 mothers, 62 fathers. GTS mothers had worse HRQoL than controls on 5 of the 8 SF-36 dimensions and 1 of the 4 WHOQOL-BREF dimensions, while GTS fathers had worse HRQoL on 2 of the WHOQOL-BREF dimensions. GTS mothers had poorer HRQoL than fathers. GTS mothers had more depression than control mothers and GTS fathers had more anxiety than control fathers. GTS adolescents had worse HRQoL than controls on 5 of the 9 VSP-A dimensions. Factors significantly related to parental HRQoL were anxiety, depression, GTS adolescents' HRQoL and, concerning mothers, behavioural and emotional adolescents' problems; concerning fathers, severity of vocal tics, duration since first symptoms. This study provides a better understanding of poorer HRQoL and psychiatric morbidity of GTS adolescents' parents. Clinicians should pay attention to their emotional well-being and HRQoL and be aware that mothers and fathers are differently affected.

Course of Tourette Syndrome and Comorbidities in a Large Prospective Clinical Study

OBJECTIVE

Tourette syndrome (TS) is a childhood-onset neurodevelopmental disorder characterized by tics and frequent comorbidities. Although tics often improve during adolescence, recent studies suggest that comorbid obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD) tend to persist. This large prospective follow-up study describes the clinical course of tics and comorbidities during adolescence and the prevalence of coexisting psychopathologies.

METHOD

The clinical cohort was recruited at the Danish National Tourette Clinic, and data were collected at baseline (n = 314, age range 5-19 years) and at follow-up 6 years later (n = 227) to establish the persistence and severity of tics and comorbidities. During follow-up, the Development and Well-Being Assessment (DAWBA) was used to diagnose coexisting psychopathologies. Repeated measures of severity scores were modeled using mixed effects models.

RESULTS

Tic severity declined yearly (0.8 points, CI: 0.58-1.01, on the Yale Global Tic Severity Scale [YGTSS]) during adolescence; 17.7% of participants above age 16 years had no tics, whereas 59.5% had minimal or mild tics, and 22.8% had moderate or severe tics. Similarly, significant yearly declines in severity of both OCD (0.24, CI: 0.09-0.39, on the Yale-Brown Obsessive Compulsive Scale for Adults [Y-BOCS] and Yale-Brown Obsessive Compulsive Scale for Children [CY-BOCS]) and ADHD (0.42, CI: 0.32-0.52, DSM-IV) were recorded. At follow-up, 63.0% of participants had comorbidities or coexistent psychopathologies, whereas 37.0% had pure TS.

CONCLUSION

Severity of tics, OCD, and ADHD were significantly associated with age and declined during adolescence. However, considerable comorbidities and coexisting psychopathologies persist throughout adolescence and require monitoring by clinicians.

Gilles de la Tourette Syndrome, Depression, Depressive Illness, and Correlates in a Child and Adolescent Population

OBJECTIVE

Gilles de la Tourette syndrome (GTS) and depression are both common disorders. It has been suggested that depression occurs in 13%-76% GTS patients. Despite this, there are few studies into the specific relationships and correlates between the two disorders. There is only some consensus as to the precise relationship between the two disorders.

MATERIALS AND METHODS

We undertook the study to investigate the relationship between depressive symptomatology and the core clinical features of GTS in a well-characterized clinical population of youth with this disorder. Our aim was to verify the association between depression and comorbid obsessive-compulsive disorder and explore further other potential associations highlighted in some, but not all, of the studies focused on this topic.

RESULTS

Our results demonstrated that (1) the GTS patients were significantly older than the controls, (2) the GTS patients were significantly more depressed than controls, (3) depression was associated with tic severity, (4) the Diagnostic Confidence Index scores were higher in GTS patients without depression, (5) anxiety, attention-deficit/hyperactivity disorder (ADHD), conduct disorder (CD), and behavioral problems were significantly associated with depression, and (6) finally, patients with GTS and depression have a positive family history of depression. However, obsessionality (CY-BOCS) did not differentiate between depressed and not depressed GTS patients.

CONCLUSIONS

Depression is common in patients with GTS and occurs significantly more in GTS than in controls. Depression is significantly associated with GTS factors such as tic severity, comorbidity with ADHD, and the presence of coexistent anxiety, CDs, and behavior problems. Depression is importantly significantly associated with a positive family history of depression. Intriguingly, depression in our sample was not related to obsessionality.

Tic Exacerbation in Adults with Tourette Syndrome: A Case Series

Background

Tourette syndrome (TS) has been described as peaking in adolescence with subsequent regression. We report patients who were diagnosed with TS during childhood who experienced a latent period (significant reduction in or absence of tics) followed by tic re-emergence in adulthood.

Methods

We performed a retrospective chart review of outpatients over age 21 seen at the Yale neurology clinic between January 2012 and July 2016 who were diagnosed with childhood-onset tics, and who experienced a latent period of greater than 1 year followed by an exacerbation.

Results

Sixteen patients were identified. The mean latent period was 16 years. Ten patients (62.5%) identified an exacerbation trigger, most commonly changes in substance use (five patients). Seven patients (43.8%) reported worsening of tics since childhood. Six patients (37.5%) had received pharmacological intervention for tics as children, and 15 patients (93.8%) as adults. Six of 15 patients (40.0%) had an effective response from those pharmacological intervention(s).

Discussion

Our study demonstrates that the decline in symptoms as patients age may represent temporary improvement. The latent period lasted years in our patients, different from the more rapid waxing and waning in children. A change in substance use was an important trigger. Requests for pharmacological intervention were not necessarily correlated with worsening tic severity.

Design of a Multisite Study Assessing the Impact of Tic Disorders on Individuals, Families, and Communities

BACKGROUND

Tic disorders, including Tourette syndrome, are complex, multisymptom diseases, yet the impact of these disorders on affected children, families, and communities is not well understood.

METHODS

To improve the understanding of the impacts of Tourette syndrome, two research groups conducted independent cross-sectional studies using qualitative and quantitative measures. They focused on similar themes, but distinct scientific objectives, and the sites collaborated to align methods of independent research proposals with the aim of increasing the analyzable sample size.

RESULTS

Site 1 (University of Rochester) was a Pediatric Neurology referral center. Site 2 (University of South Florida) was a Child Psychiatry referral center. A total of 205 children with tic disorders were enrolled from both studies. The University of Rochester also enrolled 100 control children in order to clearly isolate impacts of Tourette syndrome distinct from those occurring in the general population. The majority of children with tic disorders (n = 191, 93.1%) had Tourette syndrome, the primary population targeted for these studies. Children with Tourette syndrome were similar across sites in terms of tic severity and the occurrence of comorbid conditions. The occurrence of psychiatric comorbidities in the control group was comparable with that in the general pediatric population of the United States, making this a well-justified comparison group.

CONCLUSIONS

Through collaboration, two sites conducting independent research developed convergent research methods to enable pooling of data, and by extension increased power, for future analyses. This method of collaboration is a novel model for future epidemiological research of tic disorders.

Tics in the Pediatric Population: Pragmatic Management

BACKGROUND

Primary tic disorders, notably Tourette syndrome, are very common movement disorders in childhood. However, the management of such patients still poses great therapeutic challenges to medical professionals.

METHODS

Based on a synthesis of the available guidelines published in Europe, Canada, and the United States, coupled with more recent therapeutic developments, the authors provide a pragmatic guide to aid clinicians in deciding when and how to treat patients who have primary tic disorders.

RESULTS

After a systematic assessment of tics and common neuropsychiatric comorbidities (primarily attention-deficit hyperactivity disorder [ADHD] and obsessive-compulsive disorder [OCD]), the first step in treatment is a comprehensive psychoeducation of patients and families that addresses the protean phenomenology of tics and associated behaviors, coping mechanisms, prognosis, and treatment options. When more active intervention beyond watchful monitoring is indicated, hierarchical evaluation of treatment targets (i.e., tics vs. comorbid behavioral symptoms) is crucial. Behavioral treatments for tics are restricted to older children and are not readily available to all centers, mainly due to the paucity of well-trained therapists. Pharmacological treatments, such as antipsychotics for tics, stimulants and atomoxetine for ADHD, and α2A-agonists for children with tics plus ADHD, represent widely available and effective treatment options, but safety monitoring must be provided. Combined polypharmacological and behavioral/pharmacological approaches, as well as neuromodulation strategies, remain under-investigated in this population of patients.

CONCLUSIONS

The treatment of children with tics and Tourette syndrome is multifaceted. Multidisciplinary teams with expertise in neurology, psychiatry, psychology, and pediatrics may be helpful to address the complex needs of these children.

The English Version of the Gilles de la Tourette Syndrome-Quality of Life Scale for Children and Adolescents (C&A-GTS-QOL)

Gilles de la Tourette syndrome is a chronic neuropsychiatric disorder that can have a detrimental impact on the health-related quality of life of children with the condition. To date no patient-reported health-related quality of life measures have been developed for children and adolescents in the English language. This study validated the first disease-specific scale for the quantitative assessment of health-related quality of life in 118 children and adolescents with Gilles de la Tourette syndrome (C&A-GTS-QOL) following language adaptation from Italian to English in the United Kingdom. Standard statistical methods were used to test the psychometric properties of the rating scale. Principal component factor analyses led to the identification of six health-related quality of life domains (cognitive, copro-phenomena, psychological, physical, obsessive-compulsive, and activities of daily living), explaining 66.7% of the overall variance. The C&A-GTS-QOL demonstrated satisfactory scaling assumptions and acceptability; validity was supported by interscale correlations (range 0.2-0.7), confirmatory factor analysis, and correlation patterns with other rating scales and clinical variables.

Tourette Syndrome and Comorbid Neuropsychiatric Conditions

Tourette syndrome is a neuropsychiatric condition characterized by both motor and phonic tics over a period of at least 1 year with the onset in childhood or adolescence. Apart from the tics, most of the patients with Tourette syndrome have associated neuropsychiatric comorbidities consisting of attention deficit hyperactivity disorder, obsessive compulsive disorder, rage attacks, sleep issues, depression, and migraine. Patients may also have physical complications directly from violent motor tics which can rarely include cervical myelopathy, arterial dissection, and stroke. The purpose of this article is to review the associated neuropsychiatric comorbidities of Tourette syndrome with emphasis on recent research.

Clinical effectiveness and patient perspectives of different treatment strategies for tics in children and adolescents with Tourette syndrome: a systematic review and qualitative analysis

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental condition characterised by chronic motor and vocal tics affecting up to 1% of school-age children and young people and is associated with significant distress and psychosocial impairment.

OBJECTIVE

To conduct a systematic review of the benefits and risks of pharmacological, behavioural and physical interventions for tics in children and young people with TS (part 1) and to explore the experience of treatment and services from the perspective of young people with TS and their parents (part 2).

DATA SOURCES

For the systematic reviews (parts 1 and 2), mainstream bibliographic databases, The Cochrane Library, education, social care and grey literature databases were searched using subject headings and text words for tic* and Tourette* from database inception to January 2013.

REVIEW/RESEARCH METHODS

For part 1, randomised controlled trials and controlled before-and-after studies of pharmacological, behavioural or physical interventions in children or young people (aged < 18 years) with TS or chronic tic disorder were included. Mixed studies and studies in adults were considered as supporting evidence. Risk of bias associated with each study was evaluated using the Cochrane tool. When there was sufficient data, random-effects meta-analysis was used to synthesize the evidence and the quality of evidence for each outcome was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. For part 2, qualitative studies and survey literature conducted in populations of children/young people with TS or their carers or in health professionals with experience of treating TS were included in the qualitative review. Results were synthesized narratively. In addition, a national parent/carer survey was conducted via the Tourettes Action website. Participants included parents of children and young people with TS aged under 18 years. Participants (young people with TS aged 10-17 years) for the in-depth interviews were recruited via a national survey and specialist Tourettes clinics in the UK.

RESULTS

For part 1, 70 studies were included in the quantitative systematic review. The evidence suggested that for treating tics in children and young people with TS, antipsychotic drugs [standardised mean difference (SMD) -0.74, 95% confidence interval (CI) -1.08 to -0.41; n = 75] and noradrenergic agents [clonidine (Dixarit(®), Boehringer Ingelheim) and guanfacine: SMD -0.72, 95% CI -1.03 to -0.40; n = 164] are effective in the short term. There was little difference among antipsychotics in terms of benefits, but adverse effect profiles do differ. Habit reversal training (HRT)/comprehensive behavioural intervention for tics (CBIT) was also shown to be effective (SMD -0.64, 95% CI -0.99 to -0.29; n = 133). For part 2, 295 parents/carers of children and young people with TS contributed useable survey data. Forty young people with TS participated in in-depth interviews. Four studies were in the qualitative review. Key themes were difficulties in accessing specialist care and behavioural interventions, delay in diagnosis, importance of anxiety and emotional symptoms, lack of provision of information to schools and inadequate information regarding medication and adverse effects.

LIMITATIONS

The number and quality of clinical trials is low and this downgrades the strength of the evidence and conclusions.

CONCLUSIONS

Antipsychotics, noradrenergic agents and HRT/CBIT are effective in reducing tics in children and young people with TS. The balance of benefits and harms favours the most commonly used medications: risperidone (Risperdal(®), Janssen), clonidine and aripiprazole (Abilify(®), Otsuka). Larger and better-conducted trials addressing important clinical uncertainties are required. Further research is needed into widening access to behavioural interventions through use of technology including mobile applications ('apps') and video consultation.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002059.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The prevalence of diagnosed tourette syndrome in Canada: A national population-based study

OBJECTIVE

The objective of this study was to examine: (1) the prevalence of diagnosed Tourette syndrome in Canada by sex in youth (aged 12-17) and adults and (2) socioeconomic factors in this population.

BACKGROUND

The majority of epidemiological studies of tics have focused on children and youth, with few studies describing the prevalence of tics in adult populations.

METHODS

Canadian data on Tourette syndrome prevalence were derived from the Canadian Community Health Survey 2010 and 2011 cycles, a Statistics Canada population-based cross-sectional survey that collects information related to health status. We determined the prevalence of diagnosed Tourette syndrome and examined sociodemographic factors, including age, sex, education, income, employment, and birthplace.

RESULTS

Overall, 122,884 Canadians participated in the surveys, with 122 participants diagnosed with Tourette syndrome. The prevalence of Tourette syndrome was higher in males in youth: 6.03 per 1000 (95% confidence interval: 3.24-8.81) in males versus 0.48 per 1,000 (95% confidence interval: 0.05-0.91) in females, with a prevalence risk ratio of 5.31 (95% confidence interval: 2.38-11.81). In adults, the prevalence of Tourette syndrome was 0.89 per 1,000 (95% confidence interval: 0.48-1.29) in males versus 0.44 (95% confidence interval: 0.16.0-0.71) in females, with a prevalence risk ratio of 1.93 (95% confidence interval: 1.21-3.08). After adjusting for age and sex, adults with Tourette syndrome had lower odds of receiving postsecondary education or being employed and higher odds of having income lower than the median and receiving governmental support.

CONCLUSION

Data on the prevalence of Tourette syndrome in adults are scarce because most studies focus on children. Our data demonstrate a decreasing prevalence risk ratio for sex in adults compared to children. A diagnosis of Tourette syndrome is associated with lower education, income, and employment in adulthood. © 2016 International Parkinson and Movement Disorder Society.

Comorbidities, Social Impact, and Quality of Life in Tourette Syndrome

Tourette syndrome (TS) is more than having motor and vocal tics, and this review will examine the varied comorbidities as well as the social impact and quality of life (QoL) in individuals with TS. The relationship between any individual and his/her environment is complex, and this is further exaggerated in the case of a person with TS. For example, tics may play a significant role in shaping the person's experiences, perceptions, and interactions with the environment. Furthermore, associated clinical features, comorbidities, and coexisting psychopathologies may compound or alter this relationship. In this regard, the common comorbidities include attention-deficit hyperactivity disorder and disruptive behaviors, obsessive compulsive disorder, and autism spectrum disorder, and coexistent problems include anxiety, depression, and low self-esteem, which can all lead to poorer psychosocial functioning and QoL. Thus, the symptoms of TS and the associated comorbid conditions may interact to result in a vicious cycle or a downward spiraling of negative experiences and poor QoL. The stigma and social maladjustment in TS and the social exclusion, bullying, and discrimination are considered to be caused in large part by misperceptions of the disorder by teachers, peers, and the wider community. Improved community and professional awareness about TS and related comorbidities and other psychopathologies as well as the provision of multidisciplinary services to meet the complex needs of this clinical population are critical. Future research to inform the risk and resilience factors for successful long-term outcomes is also warranted.

Tourette syndrome in children and adolescents: aetiology, presentation and treatment

Tourette syndrome is a complex neuropsychiatric disorder of juvenile onset, characterised by motor and phonic tics. It is associated with a number of comorbid psychiatric conditions and a reduced quality of life in the young person and with parenting stress, caregiver burden and psychopathology in the parents. The global prevalence (about 1%) is higher than previously thought, with a strong male preponderance. Evidence is emerging that Tourette syndrome is not a unified disorder; rather, it encompasses a number of subtypes, characterised by complexity of tics and the simultaneous presence of other behaviours or disorders. This article discusses the aetiology of the syndrome, and examines its clinical features and comorbid psychiatric conditions and psychopathologies. Assessment and diagnosis are also discussed. Psychoeducation is a cornerstone of management, augmented with behavioural and/or pharmacological treatments. Newer therapies, such as deep brain stimulation, offer tantalising possibilities, but further research is still needed.

Increased risks of tic disorders in children with epilepsy: A nation-wide population-based case-control study in Taiwan

Both epilepsy and tic disorders may share common mechanisms with the involvement of abnormal cortical-basal ganglion circuit connection and dopaminergic dysfunction. However, the association between epilepsy and tic disorders has never been studied. This study investigated the risks of developing tic disorders among children with epilepsy using databases of a universal health insurance system in Taiwan. The data analyzed in this study were retrieved from the National Health Insurance Research Database in Taiwan. The study cohort included children with epilepsy between 2001 and 2007 (n=2629) and a three-fold age- and gender-matched controls (n=7887). All subjects were followed up for 3 years from the date of cohort entry to identify their admissions due to tic disorders (ICD-9-CM codes 307.2, 307.20-307.23). Cox hazard regression analysis was performed to estimate the effect of epilepsy on the occurrence of tics. The epilepsy cohort had a higher prevalence of tics (1.7% vs. 0.2%), and a 8.70-fold increased risk of developing a tic disorder compared with the controls (adjusted hazard ratio (AHR) 8.70, 95% confidence interval (CI) 4.26-16.37, p<0.001). Male patients were observed to have a higher risk of developing a tic disorder (AHR 1.90, 95% CI=1.04-3.46, p<0.001) compared to female individuals. Patients with multiple antiepileptic drugs treatment also exhibited higher crude OR for developing tic disorders. This nationwide population-based cohort study, for the first time, demonstrated that there is a significantly increased risk for tic disorders among children with epilepsy. We also found males, attention deficit disorder and the use of multiple AEDs to be independent risk factors of tic disorders. Closely evaluating possible tic disorders would be crucial for improving the outcome and life quality in children with epilepsy.

The effects of Gilles de la Tourette syndrome and other chronic tic disorders on quality of life across the lifespan: a systematic review

Gilles de la Tourette syndrome (GTS) and other chronic tic disorders are neurodevelopmental conditions characterized by the presence of tics and associated behavioral problems. Whilst converging evidence indicates that these conditions can affect patients' quality of life (QoL), the extent of this impairment across the lifespan is not well understood. We conducted a systematic literature review of published QoL studies in GTS and other chronic tic disorders to comprehensively assess the effects of these conditions on QoL in different age groups. We found that QoL can be perceived differently by child and adult patients, especially with regard to the reciprocal contributions of tics and behavioral problems to the different domains of QoL. Specifically, QoL profiles in children often reflect the impact of co-morbid attention-deficit and hyperactivity symptoms, which tend to improve with age, whereas adults' perception of QoL seems to be more strongly affected by the presence of depression and anxiety. Management strategies should take into account differences in age-related QoL needs between children and adults with GTS or other chronic tic disorders.

Longitudinal Magnetic Resonance Imaging (MRI) Analysis of the Developmental Changes of Tourette Syndrome Reveal Reduced Diffusion in the Cortico-Striato-Thalamo-Cortical Pathways

There is evidence that cortico-striato-thalamo-cortical pathways are involved in Tourette syndrome. We performed a longitudinal imaging study in 22 patients and 21 healthy controls in order to examine the development of tics and its correlation with magnetic resonance imaging (MRI) findings. Patients were divided in a group with persisting and a group with remission of tics. We found a decrease in volume of left putamen in controls, but not in patients. We found changes in mean diffusivity between patients and controls in right caudate nucleus, thalamus, and frontal lobe. In contrast to controls, parallel and perpendicular diffusivity decreased in patients and were most pronounced in the patients with persisting tics compared to those with remission. The findings suggest that the development of the brain in patients with remission resembles the normal development more than in patients with persistent tics. This could reflect a change in brain structure or compensatory mechanisms in the brain.

Tourette syndrome and comorbid ADHD: causes and consequences

Attention deficit hyperactivity disorder (ADHD) is the most common comorbid condition in patients with Tourette syndrome (TS). The co-occurrence of ADHD and TS is in most cases associated with a higher social and psychopathological impairment. Comorbidity between Tourette and ADHD appears to have a complex and partially known pathogenesis in which genetic, environmental, and neurobiological factors can be implicated. Genetic studies have revealed an involvement of dopaminergic, catecholaminergic, and GABAergic genes that modulated the activity of neurotransmitters. Furthermore, there are a lot of networks implicated in the development of ADHD and TS, involving cortical and striatal areas and basal ganglia. Although a large number of studies tried to find a common pathogenesis, the complex pathways responsible are not clear. The genes implicated in both disorders are currently unidentified, but it is probable that epigenetic factors associated with neural modifications can represent a substrate for the development of the diseases.

CONCLUSION

In this paper, recent advances in neurobiology of ADHD and TS are reviewed, providing a basis for understanding the complex common pathogenesis underlying the frequent co-occurrence of the two conditions and the therapeutic choices.

A personal 35 year perspective on Gilles de la Tourette syndrome: prevalence, phenomenology, comorbidities, and coexistent psychopathologies

This Series is a personal narrative of my experience with patients with Gilles de la Tourette syndrome and covers its definition and history since the first description in 1825. Controversy entered the prevalence debate early. Although originally considered very rare, in the 1980s, Tourette's syndrome was reported to be common. However, Tourette's syndrome has been shown to occur at a prevalence of about 0·85% to 1%. Tourette's syndrome is more common in the male population, more prominent during childhood, and usually improves, but does not disappear with age. Tourette's syndrome is considered less common in people of sub-Saharan black African, African-American, and American Hispanic ethnic origin. The phenomenology is similar worldwide, indicating a biological basis. The hallmark characteristics are multiple motor and one or more vocal/phonic tics. Other associated features include premonitory urges, a waxing and waning course, and to a much lesser degree, coprolalia. Comorbid disorders are common and are suggested to include obsessive-compulsive disorder and behaviours, attention deficit hyperactivity disorder, and autistic spectrum disorder. Coexistent psychopathologies are suggested to include depression and conduct and personality disorders. Importantly, I argue that Tourette's syndrome is not a unitary condition. Finally, I offer suggestions for future research.

ODD irritability is associated with obsessive-compulsive behavior and not ADHD in chronic tic disorders

Gilles de la Tourette syndrome (TS) and chronic tic disorder (CT) are often associated with a variety of behavioral comorbidities including attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive behavior (OCB), oppositional-defiant disorder (ODD) and temper outbursts. ODD is often associated with ADHD but its links to other symptoms of TS/CT is not as clear. This study examined whether the various symptoms of ODD were differentially linked to the various comorbidities in TS. A clinical sample of 135 children diagnosed with TS was evaluated through parent questionnaires and semi-structured interviews. Regressions and structural equation modeling confirmed that ODD is multidimensional in a TS/CT sample and showed that OCB was associated with the irritability symptoms of ODD whereas ADHD was associated with the Headstrong symptoms of ODD. Results suggest that increased attention to the different facets of ODD may help improve our understanding of emotional symptoms in TS/CT.

Intensive outpatient comprehensive behavioral intervention for tics: A case series

Recent randomized clinical trials have established the efficacy of Comprehensive Behavioral Intervention for Tics (CBIT) in treating children and adults with Tourette syndrome and persistent tic disorders. However, the standard CBIT protocol uses a weekly outpatient treatment format (i.e., 8 sessions over 10 wk), which may be inconvenient or impractical for some patients, particularly patients, who are required to travel long distances in order to receive care. In contrast, an intensive outpatient program may increase accessibility to evidence-based behavioral treatments for Tourette syndrome and other persistent tic disorders by eliminating the necessity of repeated travel. This case series evaluated the use of an intensive outpatient program CBIT (IOP CBIT) for the treatment of 2 preadolescent males (ages 10 and 14 years) with Tourette syndrome. The IOP CBIT treatment protocol included several hours of daily treatment over a 4-d period. Both children evidenced notable reductions in their tics and maintained treatment gains at follow-up. Moreover, both patients and their parents expressed treatment satisfaction with the IOP CBIT format. This case series addresses an important research gap in the behavioral treatment of tic disorders literature. The patients’ treatment outcomes indicate that IOP CBIT is a promising treatment that warrants more systematic investigation.

Tourette's: syndrome, disorder or spectrum? Classificatory challenges and an appraisal of the DSM criteria

The fifth version of the Diagnostic and statistical manual of mental disorders (DSM-5) was released in May 2013 after 14 years of development and almost two decades after the last edition DSM-IV was published in 1994. We review the DSM journey with regards to Tourette Syndrome from the original publication of DSM 1 in 1952 till date. In terms of changes in DSM 5, the major shift has come in the placement of Tourette Syndrome under the 'Neurodevelopmental Disorders' alongside other disorders with a developmental origin. This review provides an overview of the changes in DSM-5 highlighting key points for clinical practice and research along with a snap shot of the current use of DSM as a classificatory system in different parts of the world and suggestions for improving the subtyping and the diagnostic confidence.

Tourette syndrome and comorbid conditions: a spectrum of different severities and complexities

To investigate clinical correlates of Tourette syndrome and to identify the impact of comorbidities, we retrospectively recruited 92 young people affected by Tourette syndrome compared with 102 healthy controls. Neuropsychological assessment included: Youth Quality of Life-Research, Multidimensional Anxiety Scale for Children, Children's Depression Inventory, and Conner's and Child Behavior Checklist; moreover, Tourette syndrome patients completed the Yale Global Tic Severity Rating Scale and the Yale-Brown Obsessive Compulsive Scale. Four clinical subgroups were identified: pure Tourette syndrome (49.8%), Tourette syndrome plus attention-deficit hyperactivity disorder (ADHD) (22.2%), Tourette syndrome plus obsessive-compulsive disorder (21.5%), and Tourette syndrome plus ADHD plus obsessive-compulsive disorder (6.5%). Our findings suggested that emotional lability appeared in all Tourette syndrome subgroups, independently from comorbidities, representing a clinical feature of Tourette syndrome itself. Moreover, our data suggested that all 4 clinical subgroups had higher statistically significant behavioral problems compared with the healthy controls (P = .000), whereas affective and anxiety symptoms were overrepresented in Tourette syndrome plus comorbidities subgroups. Finally, Tourette syndrome patients had a lower quality of life compared with the healthy controls. These differences were statistically significant between the pure Tourette syndrome subgroups and Tourette syndrome plus comorbidities subgroups, as well as Tourette syndrome plus comorbidities subgroups and healthy controls.

The Semiology of Tics, Tourette's, and Their Associations

Gilles de la Tourette syndrome (GTS) is a prototypical neuropsychiatric disorder breaking the boundary of disciplinary dualism between neurology and psychiatry. The diagnosis of GTS is clinical and, in most cases, straightforward. Tics as a hallmark of GTS are usually easy to recognize and distinguish from other movement disorders as fragmented, repetitive, exaggerated movements resembling normal motor behavior, but appearing out of context. In complex cases, knowledge on additional characteristics and signs as, for example, tic distribution, suggestibility, voluntary tic inhibition, and presence of echo- or paliphenomena might further aid clinical diagnosis. However, although defining GTS, tics are rarely the main issue. The presence of comorbidities and coexisting psychopathologies often hampers normal development and negatively affects quality of life. Their recognition and treatment is paramount. Here, we review existing literature and provide a comprehensive update on the multifarious aspects of the movement disorder and neuropsychiatry of GTS. We also provide a list of associated movement disorders known to occur in GTS patients and discuss differential diagnoses to be considered in atypical cases. We finally comment on available treatment options.