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

Prevalence of mass social media-induced illness presenting with Tourette-like behavior in Germany between 2019 and 2021

Starting in 2019, in Germany the first well documented outbreak of mass sociogenic illness induced by social media (mass social media-induced illness; MSMI) occurred presenting with functional Tourette-like behaviors (FTB). This study aimed to provide first data on the prevalence rate of MSMI-FTB in Germany between 2019 and 2021 in the general population. We conducted a large-scale representative population survey in cooperation with the USUMA market and social research institute. Between August and December 2021, n = 2.509 people (mean age: 49.5 years, range: 16-95 years, n = 1.276 females) were randomly selected, visited in their households, interviewed, and asked to answer for themselves, but also for close family members (n = 6.744). Thus, in total, we received answers for n = 9.253 people. Probable MSMI-FTB was found in n = 33 individuals (mean age at onset: 30.5 years, n = 8 females). Based on strict criteria, the diagnosis of MSMI-FTB was considered highly likely in 16/33 individuals (mean age at onset: 25.6 years, n = 2 females) corresponding to prevalence rates of 0.17% (CIlower = 0.10, CIupper = 0.28) and 0.36% (CIlower = 0.25, CIupper = 0.50), respectively. This is the first large-scale, population representative study investigating the prevalence of MSMI-FTB in the general population in Germany between 2019 and 2021. Based on the prevalence rates found, MSMI-FTB is highly relevant for health economy. Accordingly, we suggest educating healthcare professionals and the general public to avoid misdiagnosis and inefficient treatment.

Leclerc J. PROTOCOL: Mindfulness-based interventions for improving tic-related symptoms in children and adults with chronic tic disorder and Tourette's disorder: A systematic review

This is a protocol for a Cochrane Review (prototype). The objectives are as follows: This systematic review aims to summarize the available scientific literature on the effect of mindfulness-based approaches in children and adults with Chronic Tic Disorder (CTD) or Tourette Disorder (TD). More specifically, the research question is: What is the effectiveness of mindfulness-based interventions in reducing tic severity and improving overall functioning, quality of life, and co-occurring symptoms in children and adults with CTD or TD?

The role of neuroactive steroids in tic disorders

Tics are sudden, repetitive movements or vocalizations. Tic disorders, such as Tourette syndrome (TS), are contributed by the interplay of genetic risk factors and environmental variables, leading to abnormalities in the functioning of the cortico-striatal-thalamo-cortical (CSTC) circuitry. Various neurotransmitter systems, such as gamma-aminobutyric acid (GABA) and dopamine, are implicated in the pathophysiology of these disorders. Building on the evidence that tic disorders are predominant in males and exacerbated by stress, emerging research is focusing on the involvement of neuroactive steroids, including dehydroepiandrosterone sulfate (DHEAS) and allopregnanolone, in the ontogeny of tics and other phenotypes associated with TS. Emerging evidence indicates that DHEAS levels are significantly elevated in the plasma of TS-affected boys, and the clinical onset of this disorder coincides with the period of adrenarche, the developmental stage characterized by a surge in DHEAS synthesis. On the other hand, allopregnanolone has garnered particular attention for its potential to mediate the adverse effects of acute stress on the exacerbation of tic severity and frequency. Notably, both neurosteroids act as key modulators of GABA-A receptors, suggesting a pivotal role of these targets in the pathophysiology of various clinical manifestations of tic disorders. This review explores the potential mechanisms by which these and other neuroactive steroids may influence tic disorders and discusses the emerging therapeutic strategies that target neuroactive steroids for the management of tic disorders.

Sex Differences in Youth with Chronic Tic Disorder and Tourette Syndrome: Evaluation of Tic Severity, Psychological Profiles, and Quality of Life

Background: Tourette syndrome (TS) and Chronic Tic Disorder (CT) are neurodevelopmental conditions involving motor and/or phonic tics. Youth with tics may encounter feelings of isolation, diminished self-esteem and quality of life, and academic difficulties. A growing body of scientific literature suggests sex differences in youth with tics, but findings have been mixed so far. Because symptom severity peaks around puberty, understanding sex differences in tic manifestations and associated symptoms during this critical period is essential. Therefore, we aimed to assess sex differences related to tic symptoms, action planning styles, quality of life, and externalizing/internalizing symptoms in youth with tics. Methods: Our sample consisted of 66 youths with tics (19 girls) aged 7-14 (mean = 10 years). Youths were assessed with clinical interviews, as well as self- and parent-reported inventories evaluating tic symptoms, psychological profiles, and quality of life. Results: While no differences in tic symptoms were found, girls exhibited lower functional inflexibility, reduced overall functional planning effectiveness, and higher impairment in the psychological well-being subscale than boys. Additionally, girls had reduced general life satisfaction and social self-esteem. Boys reported more explosive outbursts, higher levels of hyperactivity, and more difficulties with self-concept. Conclusions: Our analyses suggested differences in several manifestations associated with tics. This introduces new perspectives that refine our understanding of sex differences. A better understanding of sex differences in tic disorders may eventually improve outcomes for all individuals living with these conditions.

Developmental stuttering, physical concomitants associated with stuttering, and Tourette syndrome: A scoping review

BACKGROUND AND PURPOSE

Developmental stuttering and Tourette syndrome (TS) are common neurodevelopmental disorders. Although disfluencies may co-occur in TS, their type and frequency do not always represent pure stuttering. Conversely, core symptoms of stuttering may be accompanied by physical concomitants (PCs) that can be confused for tics. This scoping review aimed to explore the similarities and differences between stuttering and tics in terms of epidemiology, comorbidities, phenomenology, evolution, physiopathology, and treatment. We also described the nature of PCs in stuttering and disfluencies in TS.

METHODS

A literature search on Medline, Embase and PsycInfo was executed in March 2022. From 426 studies screened, 122 were included in the review (a majority being narrative reviews and case reports).

RESULTS

TS and stuttering have several epidemiological, phenomenological, comorbidity, and management similarities suggesting shared risk factors and physiopathology (involving the basal ganglia and their connections with speech and motor control cortical regions). PCs in stuttering commonly involve the face (eyelids, jaw/mouth/lip movements) and sometimes the head, trunk and limbs. PCs can be present from early stages of stuttering and vary over time and within individuals. The function of PCs is unknown. Some individuals with TS have a distinct disfluency pattern, composed of a majority of typical disfluencies (mostly between-word disfluencies), and a mix of cluttering-like behaviors, complex phonic tics (e.g. speech-blocking tics, echolalia, palilalia), and rarely, atypical disfluencies.

CONCLUSION

Future investigations are warranted to better understand the complex relationships between tics and stuttering and address the management of disfluencies in TS and PCs in stuttering.

Compulsive sexual behavior and paraphilic interests in adults with chronic tic disorders and Tourette syndrome: a survey-based study

Early research suggested that compulsive sexual behavior (CSB) and paraphilic interests (PI) are more prevalent in adults with primary tic disorders compared to the general population. However, recent data on this topic remain scarce. We conducted an anonymous online survey capturing data on CSB and PI in adult patients with primary tic disorders. We also explored the role of antipsychotic tic medication and the impact of neuropsychiatric comorbidities like attention-deficit hyperactivity disorder and depression. In total, 62 participants (26 females/36 males) completed the survey. The prevalence of CSB and PI were 12.9% and 19.4%, respectively. There was no association with antipsychotic medication nor with symptoms of depression. However, the presence of attention-deficit hyperactivity disorder was associated with a higher prevalence of both CSB and PI. The current results contrast with earlier reports and show that in adults with primary tic disorders, the prevalence of CSB and PI is not overly prominent.

Scoping Review of Multidisciplinary Care in Tourette Syndrome

Objective

To review current multidisciplinary care practices in patients with Tourette syndrome (TS).

Background

Individuals with TS can have multiple symptoms and comorbidities and require treatment to encompass all of their needs. A multidisciplinary research or care model approaches the situation/problem from all sides and uses multiple perspectives.

Methods

A database search of Medline (using Pubmed), PsychINFO, and Scopus was performed using keywords related to multidisciplinary care and TS. The authors then screened the results for relevant information using a standardized extraction form to collect data. Next, relevant codes from text analysis were extracted with a final list agreed on with author consensus. Finally, we inferred common themes.

Results

The search revealed 2304 citations, and 87 were selected for full-text analysis. One additional article was identified by manual search. Thirty-one citations were deemed relevant. Multidisciplinary team members typically included a psychiatrist or child psychiatrist, a neurologist or child neurologist, and a psychologist or therapist at the core. Four primary benefits were associated with multidisciplinary care: establishing the diagnosis, managing the complexity of TS and its associated comorbidities, averting complications, and evaluating advanced therapies. Limitations include possible poor team dynamics and rigidity in the approach leading to an algorithmic treatment plan.

Conclusions

A multidisciplinary care model for TS is the preferred model advocated by patients, physicians, and organizations. This scoping review reveals that the impetus for multidisciplinary care rests on four primary benefits, but there is a lack of empirical evidence for defining and evaluating its use.

Adolescent Gender Differences in Tic- and Non-Tic-Related Impairments in Tourette Syndrome

We aimed to compare tic- and non-tic-related impairment experienced by adolescent girls and boys (ages 13 through 17) with Tourette syndrome and associations with age. We extracted from the electronic health record child and parental responses to the mini-Child Tourette Syndrome Impairment Scale (mini-CTIM) and other questionnaire data reflective of tic- and non-tic-related impairment of adolescents with Tourette syndrome presenting to our clinic over a 12-month period. We identified a total of 132 (49 female, 83 male) unique adolescent encounters. Mini-CTIM scores did not differ significantly between genders. Tic- and non-tic-related impairment were lower in older boys, but not older girls. Obsessive-compulsive symptoms correlated with parent-reported non-tic-related impairment experienced by adolescent girls but not boys. During adolescence, tic- and non-tic-related impairments may be less likely to improve with age in girls. Future longitudinal studies are needed to confirm this finding.

Sex and gender in neurodevelopmental conditions

Health-related conditions often differ qualitatively or quantitatively between individuals of different birth-assigned sexes and gender identities, and/or with different gendered experiences, requiring tailored care. Studying the moderating and mediating effects of sex-related and gender-related factors on impairment, disability, wellbeing and health is of paramount importance especially for neurodivergent individuals, who are diagnosed with neurodevelopmental conditions with uneven sex/gender distributions. Researchers have become aware of the myriad influences that sex-related and gender-related variables have on the manifestations of neurodevelopmental conditions, and contemporary work has begun to investigate the mechanisms through which these effects are mediated. Here we describe topical concepts of sex and gender science, summarize current knowledge, and discuss research and clinical challenges related to autism, attention-deficit/hyperactivity disorder and other neurodevelopmental conditions. We consider sex and gender in the context of epidemiology, behavioural phenotypes, neurobiology, genetics, endocrinology and neighbouring disciplines. The available evidence supports the view that sex and gender are important contributors to the biological and behavioural variability in neurodevelopmental conditions. Methodological caveats such as frequent conflation of sex and gender constructs, inappropriate measurement of these constructs and under-representation of specific demographic groups (for example, female and gender minority individuals and people with intellectual disabilities) limit the translational potential of research so far. Future research and clinical implementation should integrate sex and gender into next-generation diagnostics, mechanistic investigations and support practices.

"Unvoluntary" Movement Disorders: Distinguishing between Tics, Akathisia, Restless Legs, and Stereotypies

Tics, stereotypies, akathisia, and restless legs fall at different places on the spectrum of discrete, unwanted and potentially disabling motor routines. Unlike tremor, chorea, myoclonus, or dystonia, this subgroup of abnormal movements is characterized by the subject's variable ability to inhibit or release undesired motor patterns on demand. Though it may be sometimes clinically challenging, it is crucial to distinguish these "unvoluntary" motor behaviors because secondary causes and management approaches differ substantially. To this end, physicians must consider the degree of repetitiveness of the movements, the existence of volitional control, and the association with sensory symptoms, or cognitive-ideational antecedent. This review aims to summarize the current existing knowledge on phenomenology, diagnosis, and treatment of tics, stereotypies, akathisia, and restless leg syndrome.

Ecopipam for Tourette Syndrome: A Randomized Trial

BACKGROUND AND OBJECTIVES

All US Food and Drug Administration-approved medications for Tourette syndrome are antipsychotics, and their use is limited by the risk of weight gain, metabolic changes, and drug-induced movement disorders. Several small trials suggest that ecopipam, a first-in-class, selective dopamine 1 receptor antagonist, reduces tics with a low risk for these adverse events. This trial sought to further evaluate the efficacy, safety, and tolerability of ecopipam in children and adolescents with moderate to severe Tourette syndrome.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled, phase 2b trial. Subjects aged ≥6 to <18 years with a baseline Yale Global Tic Severity Score Total Tic Score of ≥20 were randomly assigned 1:1 to ecopipam (n = 76) or placebo (n = 77). The primary endpoint was mean change over 12 weeks in the Yale Global Tic Severity Score Total Tic Score. The Clinical Global Impression of Tourette Syndrome Severity was the secondary endpoint. Safety and tolerability were evaluated at each study visit.

RESULTS

Total tic scores were significantly reduced from baseline to 12 weeks in the ecopipam group compared with placebo (least squares mean differences -3.44, 95% confidence interval -6.09 to -0.79, P = .01). Improvement in Clinical Global Impression of Tourette Syndrome Severity was also greater in the ecopipam group (P = .03). More weight gain was seen in subjects assigned to placebo. No metabolic or electrocardiogram changes were identified. Headache (15.8%), insomnia (14.5%), fatigue (7.9%), and somnolence (7.9%) were the most common adverse events.

CONCLUSIONS

Among children and adolescents with TS, ecopipam reduces tics to a greater extent than placebo, without observable evidence of common antipsychotic-associated side effects.

Tourette syndrome and other tic disorders of childhood

Tics are repetitive, patterned, and nonrhythmic movements or vocalizations/audible sounds that are misplaced in context. Phenomenology and characteristics of tics (e.g., premonitory urge, suppressibility) differentiate them from compulsions, stereotypies, functional tic-like behaviors, and other types of hyperkinetic movement disorders. With a prevalence of approximately 1% in school-aged boys, Tourette syndrome (TS) is considered a common childhood-onset neurodevelopmental disorder, defined by the combination of at least two motor tics and at least one phonic tic lasting more than 1 year. TS is a highly heritable disorder, with a wide spectrum of severity. In some individuals, tics can cause pain, distress, functional impairment, or stigmatization. About 90% of individuals with TS have at least one mental health comorbidity (attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, anxiety/depressive disorders). These comorbidities significantly impact patients' quality of life and must therefore be screened and managed accordingly in this population. Treatment of tics is based on behavioral therapies targeting tics (habit reversal training included in the comprehensive behavioral intervention for tics, and exposure and response prevention for tics), in association with medication if needed (e.g., alpha-2-agonists, second-generation antipsychotics). Deep brain stimulation is considered an experimental option in the most severe, treatment-resistant patients. In adulthood, less than 25% of individuals still have moderate or severe tics.

Systematic Review and Meta-Analysis of Tourette Syndrome Prevalence; 1986 to 2022

BACKGROUND

Tourette syndrome (TS) is a disorder characterized by a history of multiple motor tics and the emergence of at least one vocal tic during a period of the disorder. The current investigation sought to clarify the prevalence statistics for TS using a systematic review and meta-analysis.

METHODS

This systematic review and meta-analysis covered the period between 1986 and 2022. Embase, Scopus, PubMed, Web of Science, and Google Scholar were searched to locate articles pertinent to the study topic. The I² index was used to examine the heterogeneity of the studies, and a comprehensive meta-analysis was employed to analyze the data.

RESULTS

Ultimately, 30 studies (39 outcomes) were included in the meta-analysis and systematic review. The results showed the global prevalence of TS to be 0.5% (95% confidence interval [CI], 0.3% to 0.8%), with the highest rate of spread observed in the Americas at 0.6% (95% CI, 0.2% to 1.6 %). Analyzing the subgroups of the sample revealed that the highest prevalence was associated with the population of children and adolescents at 0.7% (95% CI, 0.4% to 1.4%) and males at 0.5% (95% CI, 0.2% to 1.0%).

CONCLUSIONS

This comprehensive review and meta-analysis revealed that the prevalence of TS worldwide is sufficiently high, such that attention of medical specialists and health policy makers is warranted.

Trends of Tourette Syndrome in children from 2011 to 2021: A bibliometric analysis

Objective

Analyze the research status of Tourette Syndrome (TS) in children by CiteSpace and determine the current research hotspots and frontiers.

Materials and methods

We chose publications indexed in the Web of Science Core Collection (WoSCC) database for studies related to TS in children from 2011 to 2021. We built online cooperation maps of countries/regions, institutions, authors, journals, references, and keywords by CiteSpace, and identified hotspots and frontiers of study for children’s TS.

Results

A total of 1,232 publications about TS in children were downloaded from the WoSCC. The USA (414) was the country with the highest rate of production, and University College London (87) was the institution that had the highest publication rate. Andrea Eugenio Cavanna was the most prolific author (39 papers). There was inactive cooperation between institutions, countries/regions, and authors. The Journal of European Child &amp; Adolescent Psychiatry was the most active journal. Hot topics focused on epidemiology, comorbidities, deep brain stimulation, behavioral therapy, basal ganglia, pharmacological treatment, and risk factors of TS in children.

Conclusion

According to the CiteSpace results, this study found that authors, countries/regions, and institutions were not actively working together. Current research hotspots mainly consist of epidemiology, comorbidities, deep brain stimulation, behavior therapy, and basal ganglia. The main research trends include comorbidities, pharmacological treatment, and risk factors. Therefore, international cooperation should be strengthened in the future, and it should be mindful of the psychiatric comorbidities of TS, the choice of intervention measures, and early warning of risk factors.

Estimating the number of people with Tourette syndrome and persistent tic disorder in the United States

Estimates of the number of people in the U.S. with Tourette syndrome or other persistent tic disorders can inform service provision planning. Based on available prevalence estimates applied to 2020 population data from the U.S. Census, we estimated that 350,000-450,000 U.S. children and adults have Tourette syndrome and about one million have other persistent tic disorders. Variation across studies makes estimating the total number of people in the United States affected by these disorders challenging. More precise measurement could ensure that prevalence estimates accurately reflect all who are impacted by these disorders and who could benefit from evidence-based services.

Incidence and prevalence of Tourette syndrome and chronic tic disorders in Taiwan: a nationwide population-based study

PURPOSE

The incidence of Tourette syndrome and chronic tic disorders has seldom been evaluated in Asia.

METHODS

Using the National Taiwan Insurance Research Database, the annual standardized incidence and prevalence of Tourette syndrome (TS) and chronic tic disorders were estimated from 2007 to 2015. The pre-existing comorbidity at disease diagnosis was also evaluated.

RESULTS

From 2007 to 2015, the age- and sex-standardized incidence increased from 5.34 (95% confidence interval [CI] 5.06-5.62) per 100,000 person-years to 6.87 (95% CI 6.53-7.21) per 100,000 person-years. In children and adolescents, the age- and sex-standardized incidence increased from 19.58 (95% CI 18.42-20.75) per 100,000 person-years to 31.79 (95% CI 30.09-33.49) per 100,000 person-years. In adults, the age- and sex-standardized incidence decreased from 2.01 (95% CI 1.79-2.23) per 100,000 person-years to 1.24 (95% CI 1.07-1.42) per 100,000 person-years. The incidence rate ratio (IRR) between males and females was 3.74 (95% CI 3.32-4.22). The age- and sex-standardized prevalence increased from 37.51 (95% CI 36.75-38.27) per 100,000 people in 2007 to 84.18 (95% CI 83.02-85.35) per 100,000 people in 2015. The rate risk (RR) between males and females was 3.65 (95% CI 3.53-3.78).

CONCLUSION

The annual incidence rates of TS and chronic tic disorders increased in childhood and adolescence but decreased in adulthood from 2007 to 2015. The prevalence rates increased over the same period.

A Pilot Study on Plasma and Urine Neurotransmitter Levels in Children with Tic Disorders

Background: Tic disorders (TDs), including Tourette syndrome, are childhood-onset neuropsychiatric disorders characterized by motor and/or vocal tics that commonly affect children’s physical and mental health. The pathogenesis of TDs may be related to abnormal neurotransmitters in the cortico-striatal-thalamo-cortical circuitry, especially dopaminergic, glutamatergic, and serotonergic neurotransmitters. The purpose of this study was to preliminarily investigate the differences in the three types of neurotransmitters in plasma and urine between children with TD and healthy children. Methods: We collected 94 samples of plasma and 69 samples of urine from 3–12-year-old Chinese Han children with TD before treatment. The plasma and urine of the same number of healthy Chinese Han children, matched for age and sex, participating in a physical examination, were collected. Ultra-performance liquid chromatography-tandem mass spectrometry was used to detect the three types of neurotransmitters in the above samples. Results: The plasma levels of norepinephrine, glutamic acid, and γ-aminobutyric acid, and the urine levels of normetanephrine and 5-hydroxyindoleacetic acid were higher in the TD children than in healthy children. The area under the curve (AUC) values of the above neurotransmitters in plasma and urine analyzed by receiver operating characteristic curve analysis were all higher than 0.6, with significant differences. Among them, the combined AUC of dopamine, norepinephrine, normetanephrine, glutamic acid, and γ-aminobutyric acid in the 8–12-year-old subgroup was 0.930, and the sensitivity and specificity for TD were 0.821 and 0.974, respectively (p = 0.000). Conclusions: There are differences in plasma and urine neurotransmitters between TD children and healthy children, which lays a foundation for further research on the pathogenesis of TD.

Long-term efficacy, prognostic factors, and safety of deep brain stimulation in patients with refractory Tourette syndrome: A single center, single target, retrospective study

BACKGROUND

To evaluate the long-term efficacy, prognostic factors, and safety of posteroventral globus pallidus internus deep brain stimulation (DBS) in patients with refractory Tourette syndrome (RTS).

METHODS

This retrospective study recruited 61 patients with RTS who underwent posteroventral globus pallidus internus (GPi) DBS from January 2010 to December 2020 at the Chinese People's Liberation Army General Hospital. The Yale Global Tic Severity Scale (YGTSS), Yale-Brown Obsessive-Compulsive Scale (YBOCS), Beck Depression Inventory (BDI), Gilles de la Tourette Syndrome Quality-of-Life Scale (GTS-QOL) were used to evaluate the preoperative and postoperative clinical condition in all patients. Prognostic factors and adverse events following surgery were analyzed.

RESULTS

Patient follow up was conducted for an average of 73.33 ± 28.44 months. The final postoperative YGTSS (32.39 ± 22.34 vs 76.61 ± 17.07), YBOCS (11.26 ± 5.57 vs 18.31 ± 8.55), BDI (14.36 ± 8.16 vs 24.79 ± 11.03) and GTS-QOL (39.69 ± 18.29 vs 78.08 ± 14.52) scores at the end of the follow-up period were significantly lower than those before the surgery (p < 0.05). While age and the duration of follow-up were closely related to prognosis, the disease duration and gender were not. No serious adverse events were observed and only one patient exhibited symptomatic deterioration.

CONCLUSIONS

Posteroventral-GPI DBS provides long-term effectiveness, acceptable safety and can improve the quality of life in RTS patients. Moreover, DBS is more successful among younger patients and with longer treatment duration.

Influence of sex on tic severity and psychiatric comorbidity profile in patients with pediatric tic disorder

AIM

To investigate sex-related differences in tic severity, tic-related impairments, and psychiatric comorbidities in childhood.

METHOD

In this cross-sectional study, tic severity/impairment and demographic factors were collected from 270 children and young people (aged 5-17y, mean 10y 6mo, SD 3y 4mo; 212 males and 58 females) with a tic disorder diagnosis at a specialty clinic. Psychiatric diagnoses and corresponding screening questionnaire scores were collected for attention-deficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), major depressive disorder, and anxiety disorders. Logistic regression was used to compare the effect of sex and age on psychiatric comorbid diagnoses. The Mann-Whitney U test and t-tests were used to assess differences in questionnaire score distribution between sexes.

RESULTS

Females had more severe motor tics (12.55 vs 10.81, p=0.01) and higher global severity scores (38.79 vs 32.66, p=0.03) on the Yale Global Tic Severity Scale. Females were less likely to be diagnosed with ADHD (odds ratio=0.48, 95% confidence interval=0.26-0.89). No significant sex difference was observed in diagnosis rates or symptom severity scores for anxiety or OCD. Females had significantly higher scores than males on the Children's Depression Inventory, Second Edition.

INTERPRETATION

The higher level of motor tic severity and global severity in females further supports the differential natural history of tic disorders in females. Females with tic disorders may be underdiagnosed for ADHD.

European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part I: assessment

In 2011 a working group of the European Society for the Study of Tourette Syndrome (ESSTS) has developed the first European assessment guidelines for Tourette syndrome (TS). Now, we present an updated version 2.0 of these European clinical guidelines for Tourette syndrome and other tic disorders, part I: assessment. Therefore, the available literature has been thoroughly screened, supplemented with national guidelines across countries and discussions among ESSTS experts. Diagnostic changes between DSM-IV and DSM-5 classifications were taken into account and new information has been added regarding differential diagnoses, with an emphasis on functional movement disorders in both children and adults. Further, recommendations regarding rating scales to evaluate tics, comorbidities, and neuropsychological status are provided. Finally, results from a recently performed survey among ESSTS members on assessment in TS are described. We acknowledge that the Yale Global Tic Severity Scale (YGTSS) is still the gold standard for assessing tics. Recommendations are provided for scales for the assessment of tics and psychiatric comorbidities in patients with TS not only in routine clinical practice, but also in the context of clinical research. Furthermore, assessments supporting the differential diagnosis process are given as well as tests to analyse cognitive abilities, emotional functions and motor skills.

The relationship between allergic diseases and tic disorders: A systematic review and meta-analysis

This systematic review aims to 1) explore the association between tic disorders (TD) and allergic diseases (AD), 2) judge whether patients with a diagnosis of TD are prone to suffer from a specific AD, by compiling the literature and analyzing the evidence. A literature search was conducted in PubMed and Embase database on February 24, 2021. The inclusion criteria for the literature were all comparative studies that reported TD patients were diagnosed with allergic illness as well. We identified that TD is positively associated with asthma, allergic rhinitis and allergic conjunctivitis, respectively. Especially, provisional tic disorder (PTD) patients might be more likely to suffer from these three AD, although it is still difficult to accurately predict which specific AD is prone to be accompanied by a specific TD. Shared genetic and etiological factors are suggested responsible for the AD-TD association. Large prospective cohort studies in future might shed light on a deep understanding of the relationship between immune disorders and tics.

The female Tourette patient: Sex differences in Tourette Disorder

Tourette Disorder (TD) is a male predominant neurodevelopmental disorder characterized by tics and frequent psychiatric comorbidities. Girls with TD have later peak symptoms, less remission with age, and worse impairment from tics, particularly in adulthood. Female TD patients are less likely to have Attention Deficit Hyperactivity Disorder and more likely to have anxiety and mood disorders. Hyperandrogenism is associated with TD in both sexes, and neuroanatomic sexual dimorphism is reduced in adult TD patients. Some women report catamenial tics, which may relate to estrogen withdrawal or rises in allopregnanolone. Limited data suggest that several neuroanatomic alterations present in boys with TD are not present in girls with TD. Female sex predicts better response to haloperidol. Further research into female tic pathophysiology may influence sex-specific treatment development.

Developing a provincial patient support network for children and families affected by Tourette syndrome and/or obsessive-compulsive disorder: results of a stakeholder consultation

BACKGROUND

Tourette syndrome and OCD are disorders that frequently occur in children and cause a high level of disability. In Alberta there is a huge delivery gap in providing healthcare services for children with TS and OCD. A stakeholder consultation was performed to ascertain how service delivery could be improved across the province and to inform the development of a provincial information and support organization, the Tourette OCD Alberta Network.

METHODS

A mixed-methods study was employed: 10 parents were recruited for interview and 140 parents responded to a survey.

RESULTS

Qualitative data showed there was often an absence of a clear pathway to access healthcare for people with TS and OCD. The negative impact of not receiving treatment, information, and resources in a timely and prompt manner was also revealed. Good clinical practice existed across the province but too often it was hindered by a shortage of knowledge about TS and OCD. In schools, learning for students with TS and OCD was also impaired by educators' lack of knowledge and preparedness in relation to the disorders.

CONCLUSIONS

This study identified ways that challenges with healthcare access, school learning, and seeking information can be overcome. Skills-based training webinars, educational outreach in schools, and peer support were recognized as actions for improving healthcare outcomes for people with TS and OCD. The aim of the Tourette OCD Alberta Network is to provide services and support that directly address the healthcare service delivery shortfalls shown in this study.

Driving with Tic Disorders: An International Survey of Lived Experiences

Background

Little is known about the lived experiences of individuals with tic disorders when driving vehicles or trying to obtain a driving license.

Objective

To survey the driving‐related experiences of adults with tic disorders.

Methods

A global survey was disseminated via social media, international patient organizations, and experts between April 27, 2020 and July 20, 2020.

Results

Participants were 228 adult individuals self‐reporting a confirmed diagnosis of Tourette syndrome or chronic tic disorder. Of these, 183 (87.7%) had a driver's license. A minority (9%) reported that they had found it hard to pass the driving test. Tics only interfered with driving “a bit” (58.5%) or “not at all” (33%). A majority of participants reported being able to suppress their tics (39.5%) or that their tics are unchanged (28.5%) while driving. Nearly half of the participants (46.5%) had been involved in accidents, but only a negligible percentage (3.2%) considered that these were linked to the tics. Participants without a driver's license (n = 28, 12.3%) reported significantly more severe tics, compared to those with a license. The majority of these (60.7%) identified their tics as the main reason for not having a license and 64.3% said that they would like to receive support to obtain one.

Conclusions

The majority of surveyed participants with chronic tic disorders reported minimal difficulties with driving. However, a non‐negligible minority of more severe cases struggle with driving or refrain from driving altogether and would benefit from additional support. The results have implications for clinicians and vehicle licensing agencies.

Effect of maternal smoking during pregnancy on Tourette syndrome and chronic tic disorders among offspring: a systematic review and meta-analysis

Current studies have controversial reports about the effect of maternal smoking during pregnancy (MSDP) on the risk of psychiatric disorders among offspring. The purpose of this systematic review and meta-analysis was to assess the effect of MSDP on the risk of Tourette syndrome (TS) and chronic tic disorders (CTD) among offspring. A systematic search using PubMed, Scopus, and Web of Science was conducted up to July 2019 to retrieve potential studies in English. Fixed and random-effects meta-analyses was performed to estimate pooled relative risk (RR) with 95% confidence interval (CI) according to heterogeneity. The methodological quality of the included studies was evaluated using the Newcastle-Ottawa Scale. Heterogeneity among studies was explored using the I² statistic. Of the 641 studies from the initial search, 7 were included in the quantitative synthesis (3 cohort and 4 case control studies). Overall, MSDP increased the risk of TS and CTD among the offspring by 35% (pooled RR, 1.35; 95% CI, 1.17–1.56; I²=45.8%; P-value=0.08). The results of this meta-analysis revealed that there is a significant association between MSDP and the risk of TS and CTD in offspring, and MSDP may be considered a potential risk factor for TS and CTD.

Cross-cultural adaptation and psychometric evaluation of the French version of the Gilles de la Tourette Syndrome Quality of Life Scale (GTS-QOL)

INTRODUCTION

The Gilles de la Tourette Syndrome-Quality of Life Scale (GTS-QOL) is a self-rated disease-specific questionnaire to assess health-related quality of life of subjects with GTS. Our aim was to perform the cross-cultural adaptation of the GTS-QOL into French and to assess its psychometric properties.

METHODS

The GTS-QOL was cross-culturally adapted by conducting forward and backward translations, following international guidelines. The psychometric properties of the GTS-QOL-French were assessed in 109 participants aged 16 years and above with regard to factor structure, internal consistency, reliability and convergent validity with the MOVES (Motor tic, Obsessions and compulsions, Vocal tic Evaluation Survey) and the WHOQOL-BREF (World Health Organization Quality of Life Brief).

RESULTS

Exploratory factor analysis of the GTS-QOL-French resulted in a 6-factor solution and did not replicate the original structure in four subscales. The results showed good acceptability (missing values per subscale ranging from 0% to 0.9%), good internal consistency (Cronbach's alpha ranging from 0.68 to 0.94) and good test-retest reliability (intraclass correlation coefficients ranging from 0.70 to 0.81). Convergent validity with the MOVES and WHOQOL-BREF scales showed high correlations.

DISCUSSION

Our study provides evidence of the good psychometric properties of the GTS-QOL-French. The cross-cultural adaptation and validation of this specific instrument will make it possible to assess health-related quality of life in French-speaking subjects with GTS. The GTS-QOL-French could be recommended for use in future research.

The cognitive neuropsychiatry of Tourette syndrome

Introduction: Converging evidence from both clinical and experimental studies has shown that Tourette syndrome (TS) is not a unitary condition, but a cluster of multiple phenotypes, which encompass both tics and specific behavioural and cognitive symptoms (mainly attention-deficit and hyperactivity disorder and obsessive-compulsive disorder). Methods: We conducted a narrative review of the recent literature on the cognitive neuropsychiatry of TS. Results: Although clinical research has shown that TS is not associated with cognitive deficits per se, the findings of recent studies have suggested the presence of subtle alterations in specific cognitive functions. A promising line of research on imitative behaviour could provide a common background for the alterations in executive control and social cognition observed in TS. Two different (but not mutually exclusive) neurocognitive theories have recently suggested that TS could originate from altered perception-action binding and social decision-making dysfunction, respectively. Conclusions: Since the presence of behavioural comorbidities influences individualised treatment approaches, it is likely that a more precise characterisation of TS phenotypes, including cognitive aspects, will result in improved levels of care for patients with tic disorders.

Association of Tourette Syndrome and Chronic Tic Disorder With Metabolic and Cardiovascular Disorders

Importance

There are limited data concerning the risk of metabolic and cardiovascular disorders among individuals with Tourette syndrome (TS) or chronic tic disorder (CTD).

Objective

To investigate the risk of metabolic and cardiovascular disorders among individuals with TS or CTD over a period of 40 years.

Design, Settings, and Participants

This longitudinal population-based cohort study included all individuals living in Sweden between January 1, 1973, and December 31, 2013. Families with clusters of full siblings discordant for TS or CTD were further identified. Data analyses were conducted from August 1, 2017, to October 11, 2018.

Exposures

Previously validated International Classification of Diseases diagnoses of TS or CTD in the Swedish National Patient Register.

Main Outcomes and Measures

Registered diagnoses of obesity, dyslipidemia, hypertension, type 2 diabetes, and cardiovascular diseases (including ischemic heart diseases, arrhythmia, cerebrovascular diseases and transient ischemic attack, and arteriosclerosis).

Results

Of the 14 045 026 individuals in the cohort, 7804 individuals (5964 males [76.4%]; median age at first diagnosis, 13.3 years [interquartile range, 9.9-21.3 years]) had a registered diagnosis of TS or CTD in specialist care. Of 2 675 482 families with at least 2 singleton full siblings, 5141 families included siblings who were discordant for these disorders. Individuals with TS or CTD had a higher risk of any metabolic or cardiovascular disorders compared with the general population (hazard ratio adjusted by sex and birth year [aHR], 1.99; 95% CI, 1.90-2.09) and sibling controls (aHR for any disorder, 1.37; 95% CI, 1.24-1.51). Specifically, individuals with TS or CTD had higher risks for obesity (aHR, 2.76; 95% CI, 2.47-3.09), type 2 diabetes (aHR, 1.67; 95% CI, 1.42-1.96), and circulatory system diseases (aHR, 1.76; 95% CI, 1.67-1.86). The risk of any cardiometabolic disorder was significantly greater in males than in females (aHR, 2.13; 95% CI, 2.01-2.26 vs aHR, 1.79; 95% CI, 1.64-1.96), as was the risk of obesity (aHR, 3.24; 95% CI, 2.83-3.70 vs aHR, 1.97; 95% CI, 1.59-2.44). The risks were already evident from childhood (the groups were significantly different by age 8 years) and were significantly reduced with the exclusion of individuals with comorbid attention-deficit/hyperactivity disorder (aHR, 1.52; 95% CI, 1.42-1.62), while excluding other comorbidities did not significantly affect the results. Compared with patients with TS or CTD who were not taking antipsychotics, patients with a longer duration of antipsychotic treatment (>1 year) had significantly lower risks of metabolic and cardiovascular disorders.

Conclusions and Relevance

The findings of this study suggest that TS and CTD are associated with a substantial risk of metabolic and cardiovascular disorders. The results highlight the importance of carefully monitoring cardiometabolic health in patients with TS or CTD across the lifespan, particularly in those with comorbid attention-deficit/hyperactivity disorder.

Treatment of Tourette Syndrome With Attention Training Technique-A Case Series

The existing therapeutic strategies of Tourette syndrome (TS) do not lead to sufficient improvement in a significant number of patients. Recently published studies show that paying attention to tics increases whereas directing attention away decreases tic frequency. The aim of the present case series in three patients with TS was to investigate the effect of attention training technique (ATT) on TS symptoms. ATT is a technique derived from metacognitive therapy that aims on training patients to consciously (re-)focus their attention away from themselves. Friedman's chi-square test indicated a trend regarding the reduction of tic frequency and tic severity and a significant reduction of positive metacognitions from pre-baseline to follow-up. Reliable Change Indices (RCIs) are given for each measure and patient. Given the small number of patients, further studies including randomized controlled trials appear warranted.

Meta-analysis: Adulthood prevalence of Tourette syndrome

BACKGROUND

Tourette syndrome (TS) is estimated to have a prevalence of 0.30-0.77% in school aged children. Longitudinal studies suggest that roughly half-to-two-thirds of children with TS experience a substantial improvement in tic symptoms during adolescence. By contrast, few studies have examined adulthood prevalence of TS. Accurate prevalence estimates across the lifespan are needed to support regulatory and public health decisions.

METHODS

We searched PubMED and EMBASE for studies that examined the prevalence of TS in adults. We conducted a random-effects meta-analysis of logit event rates to estimate prevalence of TS across studies. Too few studies are available to conduct moderator analysis or examine publication bias. We also examined the risk ratio of TS prevalence in adults for males compared to females.

RESULTS

Three studies involving 2,356,485 participants were included. There were significant differences in TS adulthood prevalence estimates between studies ranging from 49 to 657 cases of TS per million adults. Overall prevalence of TS in adulthood was estimated to be 118 cases of TS per million adults (95%CI: 19-751 cases per million adults). There was a large amount of heterogeneity between studies (I² = 99%) that was likely related to differences in their methods of identification of TS cases. By contrast, the male:female ratio of risk of adulthood TS was similar between studies with a Risk Ratio = 2.33 (95% CI: 1.72-3.16).

CONCLUSION

Estimates of adulthood prevalence of TS are sparse and likely highly affected by differences in method of case identification. Diagnosis and diagnostic estimates of TS could be aided by including a requirement for impairment as well as potential remission criteria similar to other psychiatric conditions.

Comprehensive systematic review summary: Treatment of tics in people with Tourette syndrome and chronic tic disorders

OBJECTIVE

To systematically evaluate the efficacy of treatments for tics and the risks associated with their use.

METHODS

This project followed the methodologies outlined in the 2011 edition of the American Academy of Neurology's guideline development process manual. We included systematic reviews and randomized controlled trials on the treatment of tics that included at least 20 participants (10 participants if a crossover trial), except for neurostimulation trials, for which no minimum sample size was required. To obtain additional information on drug safety, we included cohort studies or case series that specifically evaluated adverse drug effects in individuals with tics.

RESULTS

There was high confidence that the Comprehensive Behavioral Intervention for Tics was more likely than psychoeducation and supportive therapy to reduce tics. There was moderate confidence that haloperidol, risperidone, aripiprazole, tiapride, clonidine, onabotulinumtoxinA injections, 5-ling granule, Ningdong granule, and deep brain stimulation of the globus pallidus were probably more likely than placebo to reduce tics. There was low confidence that pimozide, ziprasidone, metoclopramide, guanfacine, topiramate, and tetrahydrocannabinol were possibly more likely than placebo to reduce tics. Evidence of harm associated with various treatments was also demonstrated, including weight gain, drug-induced movement disorders, elevated prolactin levels, sedation, and effects on heart rate, blood pressure, and ECGs.

CONCLUSIONS

There is evidence to support the efficacy of various medical, behavioral, and neurostimulation interventions for the treatment of tics. Both the efficacy and harms associated with interventions must be considered in making treatment recommendations.

Treatment of Gilles de la Tourette Syndrome with Cannabis-Based Medicine: Results from a Retrospective Analysis and Online Survey

Introduction: Gilles de la Tourette syndrome (GTS) is a neuropsychiatric disorder that is characterized by motor and vocal tics and psychiatric comorbidities, including attention deficit/hyperactivity disorder (ADHD) and obsessive-compulsive behavior/disorder (OCB/OCD). From anecdotal reports and preliminary controlled studies, it is suggested that cannabis-based medicine (CBM) may improve tics and comorbidities in adults with GTS. This study was designed to further investigate efficacy and safety of CBM in GTS and specifically compare effects of different CBM. Materials and Methods: First, we performed a retrospective data analysis including all those adult patients seen at our clinic, who had used CBM for the treatment of GTS at some time. All these patients were asked to complete an online survey (second study part) to receive more detailed data about treatment with CBM. Results: From medical records, we identified 98 patients who had used CBM (most often street cannabis followed by nabiximols, dronabinol, medicinal cannabis) for the treatment of GTS: Of the 38 patients who were able to judge, 66% preferred treatment with medicinal cannabis, 18% dronabinol, 11% nabiximols, and 5% street cannabis. Altogether, CBM resulted in a subjective improvement of tics (of about 60% in 85% of treated cases), comorbidities (55% of treated cases, most often OCB/OCD, ADHD, and sleeping disorders), and quality of life (93%). The effects of CBM appear to persist in the long term. Adverse events occurred in half of the patients, but they were rated as tolerable. Dosages of all CBM varied markedly. Patients assessed cannabis (with a preference for tetrahydrocannabinol [THC]-rich strains) as more effective and better tolerated compared with nabiximols and dronabinol. These data were confirmed by results obtained from the online survey (n=40). Conclusion: From our results, it is further supported that CBM might be effective and safe in the treatment of tics and comorbidities at least in a subgroup of adult patients with GTS. In our sample, patients favored THC-rich cannabis over dronabinol and nabiximols, which might be related to the entourage effect of cannabis. However, several limitations of the study have to be taken into considerations such as the open uncontrolled design and the retrospective data analysis.

Prescriptions for Alpha Agonists and Antipsychotics in Children and Youth with Tic Disorders: A Pharmacoepidemiologic Study

Background

Trends in the use of antipsychotics and alpha agonists for the treatment of tic disorders in Canadian children, and how closely these trends align with evidence-based guidelines on the pharmacotherapy of tic disorders, have not been explored.

Methods

IQVIA's Canadian Disease and Therapeutic Index, a survey-based data set, was used to identify prescription patterns by physicians. Respondents recorded all patient visits during a 48-hour period in each quarter of the year, including patient age, gender, drug recommendation and therapeutic indication. Recommendations for alpha agonists and antipsychotics from 2012 to 2016 were analysed for children and adolescents with tic disorders.

Results

Risperidone and clonidine were the most commonly recommended medications for tic disorders over the study period, with 36,868 and 35,500 recommendations in 2016, respectively. Recommendations for clonidine increased over the study period, whereas those for risperidone decreased. Guanfacine (approved in Canada in 2013) was used less frequently than clonidine. Clonidine was more frequently recommended than antipsychotics in children younger than 6, in whom antipsychotic recommendations were uncommon. Aripiprazole was the second most commonly recommended antipsychotic for tic disorders, with 22,892 recommendations in 2016. Of the first-generation antipsychotics, pimozide was most commonly recommended (11,334 recommendations in 2016); haloperidol was infrequently recommended.

Discussion

The trends observed are in line with guideline recommendations reflected in the decreasing use of risperidone, and the growing use of clonidine and guanfacine. The growing use of aripiprazole is likely due to emerging evidence from clinical trials supporting its efficacy for tics. Recommendations for pimozide and haloperidol were limited, likely due to the greater adverse effects associated with these medications.

Effect of diet, exercise and sleep on tic severity: a scoping review protocol

INTRODUCTION

Tourette syndrome is a common childhood-onset neuropsychiatric disorder, with tics that wax and wane in frequency and severity over time. The purpose of the proposed scoping review is to map the types of evidence available pertaining to the effect of diet, sleep and exercise on tic severity and identify key concepts and gaps in research.

METHODS

Our scoping review will use the six-step framework recommended by Arksey and O'Malley, with enhancements from Levac et al and Joanna Briggs Institute. We will attempt to identify all the relevant literature regardless of study design. We will search six electronic databases, the reference lists of all selected studies and the grey literature for studies examining an association between dietary factors, sleep or physical exercise and tics, or studies of interventions targeting diet, sleep or exercise to reduce tics. Our analysis plan includes description of the reported associations among dietary factors, sleep and physical exercise and tics, the effects of interventions, the research methodologies and how outcomes are measured.

ETHICS AND DISSEMINATION

An approval from a recognised committee is not required to conduct the proposed review, as the study entails secondary analysis of the literature available publicly. For dissemination of the study, the results will be submitted for publication to peer-reviewed scientific journals and presented at relevant public forums and conferences.

Sex differences in early sensorimotor processing for speech discrimination

Sensorimotor activity in speech perception tasks varies as a function of context, cognitive load, and cognitive ability. This study investigated listener sex as an additional variable. Raw EEG data were collected as 21 males and 21 females discriminated /ba/ and /da/ in quiet and noisy backgrounds. Independent component analyses of data from accurately discriminated trials identified sensorimotor mu components with characteristic alpha and beta peaks from 16 members of each sex. Time-frequency decompositions showed that in quiet discrimination, females displayed stronger early mu-alpha synchronization, whereas males showed stronger mu-beta desynchronization. Findings indicate that early attentional mechanisms for speech discrimination were characterized by sensorimotor inhibition in females and predictive sensorimotor activation in males. Both sexes showed stronger early sensorimotor inhibition in noisy discrimination conditions versus in quiet, suggesting sensory gating of the noise. However, the difference in neural activation between quiet and noisy conditions was greater in males than females. Though sex differences appear unrelated to behavioral accuracy, they suggest that males and females exhibit early sensorimotor processing for speech discrimination that is fundamentally different, yet similarly adaptable to adverse conditions. Findings have implications for understanding variability in neuroimaging data and the male prevalence in various neurodevelopmental disorders with inhibitory dysfunction.

The Rage Attack Questionnaire-Revised (RAQ-R): Assessing Rage Attacks in Adults With Tourette Syndrome

INTRODUCTION

Although defined by the presence of tics, most patients with Gilles de la Tourette syndrome (TS) also suffer from different psychiatric disorders. While much is known about clinical characteristics of comorbidities such as attention deficit/hyperactivity disorder (ADHD), obsessive compulsive disorder (OCD), depression, and anxiety disorders, only very little is known about rage attacks. Most of this data is based on small studies in children. Until today no larger studies have been performed in adults with TS-most likely because of the lack of validated instruments. The aim of this study was to develop a new assessment and investigate rage attacks in a large sample of adults with TS and healthy individuals.

MATERIALS AND METHODS

Based on a parent questionnaire for children with TS, we generated 27 items for a revised version of a rage attack questionnaire (RAQ-R) and tested factor structure, internal consistency, as well as convergent and discriminant validity. We used an online survey and included 127 patients with TS and 645 control subjects. In addition to the RAQ-R, we used several other self-assessments to measure tic severity, quality of life, as well as several psychiatric symptoms including ADHD, OCD, depression, anxiety, and impulsivity.

RESULTS

Based on expert option and statistical analyses [including item-total correlation, skewness, inter-item correlation, and principal component analysis (PCA)], we performed an item reduction resulting in a final, 22-items version of the RAQ-R (range, 0-66). Investigating internal consistency, discriminant validity, test reliability, and factor structure, the RAQ-R demonstrated good to excellent quality criteria. As assessed by RAQ-R, rage attacks were significantly more common in patients with TS compared to controls (p < 0.001). Rage attacks could be clearly differentiated from the phenomenon of impulsivity. Although rage attacks occurred more often in individuals with ADHD, they were also found in patients with "TS only", independently from comorbid ADHD, impulsivity, and OCD. Rage attacks were found to significantly influence patients' quality of life.

CONCLUSIONS

Thus, from our data based on a large sample it is suggested that rage attacks represent a discrete comorbidity in adults with TS.

Genetic Studies of Tic Disorders and Tourette Syndrome

Tourette 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 progress 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.

Sex differences in the developing brain: insights from multimodal neuroimaging

Youth (including both childhood and adolescence) is a period when the brain undergoes dramatic remodeling and is also a time when neuropsychiatric conditions often emerge. Many of these illnesses have substantial sex differences in prevalence, suggesting that sex differences in brain development may underlie differential risk for psychiatric symptoms between males and females. Substantial evidence documents sex differences in brain structure and function in adults, and accumulating data suggests that these sex differences may be present or emerge during development. Here we review the evidence for sex differences in brain structure, white matter organization, and perfusion during development. We then use these normative differences as a framework to understand sex differences in brain development associated with psychopathology. In particular, we focus on sex differences in the brain as they relate to anxiety, depression, psychosis, and attention-deficit/hyperactivity symptoms. Finally, we highlight existing limitations, gaps in knowledge, and fertile avenues for future research.

Single center experience with medical cannabis in Gilles de la Tourette syndrome

INTRODUCTION

Patients with Gilles de la Tourette syndrome (GTS) experience reduced function and impaired quality of life. The current medical treatments for this syndrome can cause significant side effects and offer partial symptomatic relief. In a few small trials medical cannabis (MC) has been suggested to offer symptomatic relief with a relatively benign side effect profile. We conducted a real-life assessment of clinical benefit and adverse effects of chronic MC treatment among patients with GTS.

METHODS

GTS patients treated with MC were interviewed via phone regarding treatment efficacy and side effect profile from chronic MC consumption. Global efficacy was rated on a Likert scale of 1-5 and side effects of treatment were recorded.

RESULTS

Forty-Two GTS patients (33 males, mean age 34.5) were interviewed for this study. The total global impression score of efficacy was 3.85 out of a total 5 possible points. Patients reported during the free discussion part of the interview about reduction in tic severity, better sleep and improved mood as positive effects of MC. Thirty-eight patients reported any kind of benefit from treatment while 10 patients with more than one year of consumption elected to stop treatment with MC for various reasons including severe side effects as psychosis in one patient.

CONCLUSION

MC seems to hold promise in the treatment of GTS as it demonstrated high subjective satisfaction by most patients however not without side effects and should be further investigated as a treatment option for this syndrome.

Tourette syndrome: a disorder of the social decision-making network

Tourette syndrome is a common neurodevelopmental disorder defined by characteristic involuntary movements, tics, with both motor and phonic components. Tourette syndrome is usually conceptualized as a basal ganglia disorder, with an emphasis on striatal dysfunction. While considerable evidence is consistent with these concepts, imaging data suggest diffuse functional and structural abnormalities in Tourette syndrome brain. Tourette syndrome exhibits features that are difficult to explain solely based on basal ganglia circuit dysfunctions. These features include the natural history of tic expression, with typical onset of tics around ages 5 to 7 years and exacerbation during the peri-pubertal years, marked sex disparity with higher male prevalence, and the characteristic distribution of tics. The latter are usually repetitive, somewhat stereotyped involuntary eye, facial and head movements, and phonations. A major functional role of eye, face, and head movements is social signalling. Prior work in social neuroscience identified a phylogenetically conserved network of sexually dimorphic subcortical nuclei, the Social Behaviour Network, mediating many social behaviours. Social behaviour network function is modulated developmentally by gonadal steroids and social behaviour network outputs are stereotyped sex and species specific behaviours. In 2011 O'Connell and Hofmann proposed that the social behaviour network interdigitates with the basal ganglia to form a greater network, the social decision-making network. The social decision-making network may have two functionally complementary limbs: the basal ganglia component responsible for evaluation of socially relevant stimuli and actions with the social behaviour network component responsible for the performance of social acts. Social decision-making network dysfunction can explain major features of the neurobiology of Tourette syndrome. Tourette syndrome may be a disorder of social communication resulting from developmental abnormalities at several levels of the social decision-making network. The social decision-making network dysfunction hypothesis suggests new avenues for research in Tourette syndrome and new potential therapeutic targets.

Tic Severity and Treatment in Children: The Effect of Comorbid Attention Deficit Hyperactivity Disorder and Obsessive Compulsive Behaviors

While attention deficit hyperactivity disorder (ADHD) and obsessive compulsive disorder have been shown to have major impacts on quality of life in individuals with Tourette syndrome, there is comparatively little data on how the presence of these comorbidities influence tic severity and treatment. 114 children (mean age 10.25 years) were extensively clinically phenotyped at a single specialty clinic. While there was no difference in Yale Global Tic Severity Scale (YGTSS) scores in children with versus without ADHD, children with obsessive compulsive behaviors had significantly higher YGTSS scores (p = 0.008). There was a significant correlation between YGTSS scores and age (r = 0.344, p < 0.001). Children with ADHD were more likely to be treated for their tics within the first two years of diagnosis (OR 3.51, p = 0.009). As tic severity does not appear to be greater in children with ADHD, this association may relate to greater overall psychosocial impairment in children with this comorbidity.

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.

Tourette syndrome research highlights from 2016

This article presents highlights chosen from research that appeared during 2016 on Tourette syndrome and other tic disorders. Selected articles felt to represent meaningful advances in the field are briefly summarized.

Tourette syndrome research highlights from 2016

This article presents highlights chosen from research that appeared during 2016 on Tourette syndrome and other tic disorders. Selected articles felt to represent meaningful advances in the field are briefly summarized.

Gender differences in the structural connectome of the teenage brain revealed by generalized q-sampling MRI

The question of whether there are biological differences between male and female brains is a fraught one, and political positions and prior expectations seem to have a strong influence on the interpretation of scientific data in this field. This question is relevant to issues of gender differences in the prevalence of psychiatric conditions, including autism, attention deficit hyperactivity disorder (ADHD), Tourette's syndrome, schizophrenia, dyslexia, depression, and eating disorders. Understanding how gender influences vulnerability to these conditions is significant. Diffusion magnetic resonance imaging (dMRI) provides a non-invasive method to investigate brain microstructure and the integrity of anatomical connectivity. Generalized q-sampling imaging (GQI) has been proposed to characterize complicated fiber patterns and distinguish fiber orientations, providing an opportunity for more accurate, higher-order descriptions through the water diffusion process. Therefore, we aimed to investigate differences in the brain's structural network between teenage males and females using GQI. This study included 59 (i.e., 33 males and 26 females) age- and education-matched subjects (age range: 13 to 14 years). The structural connectome was obtained by graph theoretical and network-based statistical (NBS) analyses. Our findings show that teenage male brains exhibit better intrahemispheric communication, and teenage female brains exhibit better interhemispheric communication. Our results also suggest that the network organization of teenage male brains is more local, more segregated, and more similar to small-world networks than teenage female brains. We conclude that the use of an MRI study with a GQI-based structural connectomic approach like ours presents novel insights into network-based systems of the brain and provides a new piece of the puzzle regarding gender differences.

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The GQI-based structural connectomic study provides a new piece of the puzzle regarding gender differences.

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Male brains exhibit better intrahemispheric communication, and female exhibit better interhemispheric communication.

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The network organization of teenage male brains is more local and more segregated than teenage female brains.