The Effect of Nabiximols on Driving Ability in Adults with Chronic Tic Disorders: Results of a Substudy Analysis of the Double-Blind, Randomized, Placebo-Controlled CANNA-TICS Trial

Background: The multicenter, randomized, double-blind, parallel-group, phase IIIb CANNA-TICS (CANNAbinoids in the treatment of TICS) trial showed clear trends for improvement of tics, depression, and quality of life with nabiximols versus placebo in adult patients with Gilles de la Tourette syndrome and other chronic tic disorders. Although in general nabiximols was well tolerated, it is unclear whether treatment using this cannabis extract influences driving skills in patients with chronic tic disorders. Methods: Here we report results of the "Fitness to Drive" substudy of the CANNA-TICS trial. The key endpoint was fitness to drive as a binary criterion with a computerized assessment at baseline and after 9 weeks of stable treatment (week 13) with nabiximols or placebo. A patient was considered unfit to drive according to the German Federal Highway Research Institute guidelines. Results: In the substudy, a total of 64 patients (76.6% men, mean±standard deviation of age: 36.8±13.9) were recruited at two study sites. The number of patients who were fit to drive increased from 24 (55.8%) at baseline to 28 (71.8%) at week 13 among 43 patients treated with nabiximols, and decreased from 14 (66.7%) to 10 (52.6%) among 21 patients who received placebo. The risk difference (nabiximols - placebo) was 0.17 (95% confidence interval=-0.08 to 0.43) in favor of nabiximols. Specifically, only 2 of 24 (8.3%) patients in the nabiximols, but 4 of 14 (28.6%) patients in the placebo group changed for the worse from fit (at baseline) to unfit (at week 13) to drive, whereas 8 of 19 (42.1%) patients in the nabiximols, and only 2 of 7 (28.6%) patients in the placebo group improved from unfit to fit. Conclusion: Treatment with nabiximols does not impair skills relevant to driving in those patients with tic disorders who were fit to drive at baseline and even improved fitness to drive in a subset of patients who were unfit to drive before start of treatment. EudraCT number: 2016-000564-42.

Group-based comprehensive behavioral intervention for tics (CBIT) for adults with Tourette syndrome or chronic tic disorders: A pilot study

Comprehensive behavioral intervention for tics (CBIT) administered individually is an effective treatment for tics. However, the effectiveness of CBIT administered in groups for adults with Tourette syndrome and chronic tic disorders has not been investigated yet. This pilot study examined the effectiveness of group-based CBIT with respect to reduction of tic severity and tic-related impairment, as well as improvement of tic-related quality of life. Data from 26 patients were included in the intention-to-treat analyses. The Yale Global Tic Severity Scale was used to assess total tic severity and tic-related impairment. The Gilles de la Tourette - Quality of Life Scale was used to assess tic-related quality of life. These measures were administered at three points in time: at pretreatment, posttreatment, and 1-year follow-up. The results showed a significant reduction of total tic severity from pretreatment to 1-year follow-up, with larges effect sizes. Tic-related impairment and tic-related quality of life also improved significantly, although the effect sizes were smaller. Motor tics showed a stronger reduction than vocal tics. Additional analysis revealed that all change was achieved during treatment and that this effect was maintained from posttreatment to 1-year follow-up. The results of this study indicate that group-based CBIT is a promising treatment for tics.

Phenotypic Impact of Rare Potentially Damaging Copy Number Variation in Obsessive-Compulsive Disorder and Chronic Tic Disorders

BACKGROUND

Recent studies report an important-and previously underestimated-role of rare variation in risk of obsessive-compulsive disorder (OCD) and chronic tic disorders (CTD). Using data from a large epidemiological study, we evaluate the distribution of potentially damaging copy number variation (pdCNV) in OCD and CTD, examining associations between pdCNV and the phenotypes of probands, including a consideration of early- vs. late-diagnoses.

METHOD

The Obsessive-Compulsive Inventory-Revised (OCI-R) questionnaire was used to ascertain psychometric profiles of OCD probands. CNV were identified genome-wide using chromosomal microarray data.

RESULTS

For 993 OCD cases, 86 (9%) were identified as pdCNV carriers. The most frequent pdCNV found was at the 16p13.11 region. There was no significant association between pdCNV and the OCI-R total score. However, pdCNV was associated with Obsessing and Checking subscores. There was no significant difference in pdCNV frequency between early- vs. late-diagnosed OCD probands. Of the 217 CTD cases, 18 (8%) were identified as pdCNV carriers. CTD probands with pdCNV were significantly more likely to have co-occurring autism spectrum disorder (ASD).

CONCLUSIONS

pdCNV represents part of the risk architecture for OCD and CTD. If replicated, our findings suggest pdCNV impact some OCD symptoms. Genes within the 16p13.11 region are potential OCD risk genes.

Fidelity of Delivery and Contextual Factors Influencing Children's Level of Engagement: Process Evaluation of the Online Remote Behavioral Intervention for Tics Trial

Background

The Online Remote Behavioral Intervention for Tics (ORBIT) study was a multicenter randomized controlled trial of a complex intervention that consisted of a web-based behavioral intervention for children and young people with tic disorders. In the first part of a two-stage process evaluation, we conducted a mixed methods study exploring the reach, dose, and fidelity of the intervention and contextual factors influencing engagement.

Objective

This study aims to explore the fidelity of delivery and contextual factors underpinning the ORBIT trial.

Methods

Baseline study data and intervention usage metrics from participants in the intervention arm were used as quantitative implementation data (N=112). The experiences of being in the intervention were explored through semistructured interviews with children (n=20) and parent participants (n=20), therapists (n=4), and referring clinicians (n=6). A principal component analysis was used to create a comprehensive, composite measure of children and young people’s engagement with the intervention. Engagement factor scores reflected relative uptake as assessed by a range of usage indices, including chapters accessed, number of pages visited, and number of log-ins. The engagement factor score was used as the dependent variable in a multiple linear regression analysis with various contextual variables as independent variables to assess if there were any significant predictors of engagement.

Results

The intervention was implemented with high fidelity, and participants deemed the intervention acceptable and satisfactory. The engagement was high, with child participants completing an average of 7.5 of 10 (SD 2.7) chapters, and 88.4% (99/112) of participants completed the minimum of the first four chapters—the predefined threshold effective dose. Compared with the total population of children with tic disorders, participants in the sample tended to have more educated parents and lived in more economically advantaged areas; however, socioeconomic factors were not related to engagement factor scores. Factors associated with higher engagement factor scores included participants enrolled at the London site versus the Nottingham site (P=.01), self-referred versus clinic referred (P=.04), higher parental engagement as evidenced by the number of parental chapters completed (n=111; ρ=0.73; P<.001), and more therapist time for parents (n=111; ρ=0.46; P<.001). A multiple linear regression indicated that parents’ chapter completion (β=.69; t₁₁₀=10.18; P<.001) and therapist time for parents (β=.19; t₁₁₀=2.95; P=.004) were the only significant independent predictors of child engagement factor scores.

Conclusions

Overall, the intervention had high fidelity of delivery and was evaluated positively by participants, although reach may have been constrained by the nature of the randomized controlled trial. Parental engagement and therapist time for parents were strong predictors of intervention implementation, which has important implications for designing and implementing digital therapeutic interventions in child and adolescent mental health services.

International Registered Report Identifier (IRRID)

RR2-10.1186/s13063-019-3974-3

Empiric Recurrence Risk Estimates for Chronic Tic Disorders: Implications for Genetic Counseling

Background: Tourette disorder (TD) and other chronic tic disorders are neurodevelopmental/neuropsychiatric disorders characterized by motor and/or vocal tics. Family studies indicate that TD strongly aggregates within families and that other chronic tic disorders are biologically related such that studies typically combine them into any chronic tic disorder (CTD). Because of stigma, bullying, and comorbidity with other neuropsychiatric disorders, CTDs can severely impact the quality of life of individuals with these disorders.

Objectives: The genetic architecture of CTDs is complex and heterogeneous, involving a myriad of genetic variants. Thus, providing familial recurrence risks is based on empirical recurrence risk estimates rather than genetic testing. Because empiric recurrence risks for CTDs have not been published, the purpose of this study is to calculate and report these recurrence risks estimates.

Methods: Based on population prevalence and increased risk to different relatives from a large population-based family study, we calculated the empiric recurrent risk estimate for each relative type (full sibling, parents, offspring, all first-degree, and all second-degree).

Results: The recurrence risk estimate for CTDs in first-degree relatives is 29.9% [95% confidence interval (CI) = 23.2–38.5%]. The risk is higher in males, 33.7% (95% CI = 26.2–43.3%), than females, 24.3% (95% CI = 18.9–31.3%).

Conclusions: Given the complex, heterogeneous genetic architecture of CTDs, individuals concerned about recurrence risk should be referred to genetic counseling. Such counseling should include discussion of the derivation and limitations of these empiric recurrence risk estimates, including the upper and lower limits of the range of risk.

Clinical improvement following vitamin D3 supplementation in children with chronic tic disorders

PURPOSE

Vitamin D deficiency has been found in children with chronic tic disorders (CTDs). Our previous data showed that serum 25-hydroxyvitamin D [25(OH)D] level in children with CTDs was lower than that of the healthy controls and lower serum 25(OH)D level was associated with increased severity of the tic disorder. Thus, we intend to further verify this phenomenon and examine the effect of vitamin D3 on CTDs.

PATIENTS AND METHODS

In total, 120 children with CTDs and 140 normal controls were enrolled in this study, with 36/120 of those in the CTD group receiving vitamin D3 treatment for 3 months. The Yale Global Tic Severity Scale (YGTSS) and Clinical Global Impression of Severity of Illness (CGI-SI) were, respectively, used to evaluate the tic severity. High-performance liquid chromatography and tandem mass spectrometry were used to measure serum 25(OH)D level.

RESULTS

Those children with CTDs exhibited significantly lower 25(OH)D levels than did healthy controls, and these reduced 25(OH)D levels were linked to increasing severity of tic symptoms. After treatment with supplemental vitamin D3, serum 25(OH)D level and scores of YGTSS total, motor tics, phonic tics, total tic, impairment, and CGI-SI improved significantly in children with CTDs without any adverse reactions.

CONCLUSION

Supplementation vitamin D3, given its low cost and excellent safety, may be an effective means of improving symptoms in certain children with CTDs.

Pharmacoepidemiology of Tourette and Chronic Tic Disorders in Sweden 2005-2013

BACKGROUND

Monitoring "real world" dispensation patterns over time is important to build the evidence base for safe and efficient use of psychotropic drugs. In this study, we aimed to comprehensively examine the patterns of psychotropic drug dispensations in patients with Tourette and chronic tic disorders (TD/CTD) in Sweden between 2005 and 2013.

METHODS

A cohort of 6979 TD/CTD patients was identified through the Swedish National Patient Register. Their drug dispensation patterns, collected in the Swedish Prescribed Drug Register, were examined between July 1, 2005 and December 31, 2013. Frequencies of drug dispensations were further stratified by gender and comorbidities. Additionally, differences in the patterns of dispensation in children and adolescents versus adults in the last year of the follow-up were examined, as well as the time trends of the dispensations over the 8-year study period.

RESULTS

A total of 5299 (75.9%) TD/CTD patients were dispensed at least one drug during the study period. The most frequently dispensed medications were attention-deficit/hyperactivity disorder (ADHD) drugs (53.8%), antidepressants (50.7%), hypnotics/sedatives (41.7%), and antipsychotics (41.5%). Most of the medicated patients (72.1%) were dispensed more than one drug during the study period. Patterns of dispensation varied according to patient's gender, associated comorbidities, and age group. Dispensation of quetiapine and aripiprazole, antiadrenergics, ADHD drugs, antiepileptics, and hypnotics/sedatives and anxiolytics (particularly the nonbenzodiazepine types) significantly increased over time, whereas dispensation of antidepressants, typical antipsychotics, and benzodiazepine-based anxiolytics significantly decreased over the study period.

CONCLUSIONS

Long-term monitoring of these drug dispensation patterns and the study of both their beneficial and adverse effects is warranted.

Extended-Release Guanfacine Does Not Show a Large Effect on Tic Severity in Children with Chronic Tic Disorders

OBJECTIVE

To evaluate the tolerability, safety, and preliminary efficacy of extended-release guanfacine in children with chronic tic disorders, including Tourette's disorder (collectively referred to as CTD).

METHODS

This was a multisite, 8-week, randomized, double-blind, placebo-controlled trial. The primary outcome measure was the Yale Global Tic Severity Scale (YGTSS) total score. Key secondary outcomes included the Improvement item of Clinical Global Impressions-Improvement (CGI-I) scale and the Tic Symptom Self-report (TSSR). Adverse events were monitored at each visit.

RESULTS

Thirty-four subjects (23 boys and 11 girls) of ages 6 to 17 years (mean = 11.1 ± 3.1) with CTD were randomly assigned to extended-release guanfacine (n = 16) or placebo (n = 18). At baseline, the mean YGTSS total score was 26.3 ± 6.6 for the guanfacine group versus 27.7 ± 8.7 for the placebo group. Within the guanfacine group (mean final daily dose of 2.6 ± 1.1 mg, n = 14), the mean YGTSS total score declined to 23.6 ± 6.42 [t(15) = 1.84, p = 0.08; effect size = 0.35]. The results were similar in the placebo group with a score of 24.7 ± 10.54 at week 8 [t(17) = 1.83, p = 0.08; effect size = 0.38]. There was no significant difference in the rate of positive response on the CGI-I between the guanfacine group and placebo (19% [3/16] vs. 22% [4/18], p = 1.0). The most common adverse events were fatigue, drowsiness, dry mouth, headache, and irritability. Two subjects in the guanfacine group discontinued early-one because of an adverse event (depressed mood) and one because of lack of efficacy; two subjects in the placebo group discontinued because of lack of efficacy.

CONCLUSIONS

This pilot study did not confirm a clinically meaningful effect size within the guanfacine group. These results do not support the launch of a larger efficacy trial for tics in children and adolescents with CTD.

Understanding the covariation of tics, attention-deficit/hyperactivity, and obsessive-compulsive symptoms: A population-based adult twin study

Chronic tic disorders (TD), attention-deficit/hyperactivity-disorder (ADHD), and obsessive-compulsive disorder (OCD) frequently co-occur in clinical and epidemiological samples. Family studies have found evidence of shared familial transmission between TD and OCD, whereas the familial association between these disorders and ADHD is less clear. This study aimed to investigate to what extent liability of tics, attention-deficit/hyperactivity, and obsessive-compulsive symptoms is caused by shared or distinct genetic or environmental influences, in a large population-representative sample of Swedish adult twins (n = 21,911). Tics, attention-deficit/hyperactivity, and obsessive-compulsive symptoms showed modest, but significant covariation. Model fitting suggested a latent liability factor underlying the three phenotypes. This common factor was relatively heritable, and explained significantly less of the variance of attention-deficit/hyperactivity symptom liability. The majority of genetic variance was specific rather than shared. The greatest proportion of total variance in liability of tics, attention-deficit/hyperactivity, and obsessive-compulsive symptoms was attributed to specific non-shared environmental influences. Our findings suggest that the co-occurrence of tics and obsessive-compulsive symptoms, and to a lesser extent attention-deficit/hyperactivity symptoms, can be partly explained by shared etiological influences. However, these phenotypes do not appear to be alternative expressions of the same underlying genetic liability. Further research examining sub-dimensions of these phenotypes may serve to further clarify the association between these disorders and identify more genetically homogenous symptom subtypes. © 2016 Wiley Periodicals, Inc.

A randomized waitlist-controlled pilot trial of voice over Internet protocol-delivered behavior therapy for youth with chronic tic disorders

INTRODUCTION

Comprehensive Behavioral Intervention for Tics (CBIT) has been shown to be efficacious for chronic tic disorders (CTDs), but utilization is limited by a lack of treatment providers and perceived financial and time burden of commuting to treatment. A promising alternative to in-person delivery is voice over Internet protocol (VoIP), allowing for remote, real-time treatment delivery to patients' homes. However, little is known about the effectiveness of VoIP for CTDs. Therefore, the present study examined the preliminary efficacy, feasibility, and acceptability of VoIP-delivered CBIT (CBIT-VoIP).

METHODS

Twenty youth (8-16 years) with CTDs participated in a randomized, waitlist-controlled pilot trial of CBIT-VoIP. The main outcome was pre- to post-treatment change in clinician-rated tic severity (Yale Global Tic Severity Scale). The secondary outcome was clinical responder rate (Clinical Global Impressions - Improvement Scale), assessed using ratings of 'very much improved' or 'much improved' indicating positive treatment response.

RESULTS

Intention-to-treat analyses with the last observation carried forward were performed. At post-treatment (10-weeks), significantly greater reductions in clinician-rated, (F(1,18) = 3.05, p < 0.05, partial η(2 )= 0.15), and parent-reported tic severity, (F(1,18) = 6.37, p < 0.05, partial η(2 )= 0.26) were found in CBIT-VoIP relative to waitlist. One-third (n = 4) of those in CBIT-VoIP were considered treatment responders. Treatment satisfaction and therapeutic alliance were high.

DISCUSSION

CBIT can be delivered via VoIP with high patient satisfaction, using accessible, low-cost equipment. CBIT-VoIP was generally feasible to implement, with some audio and visual challenges. Modifications to enhance treatment delivery are suggested.