Some sections of this chapter have been reproduced from the online remote behavioural intervention for tics (ORBIT) trial protocol, which has been published.1
Scientific background
Tourette syndrome (TS) and chronic tic disorders (CTDs) are common, disabling, childhood-onset conditions characterised by motor and vocal tics (i.e. involuntary, repetitive movements or vocalisations) that have been present for at least 1 year.2 Affecting approximately 1% of young people (an estimated 70,000 people aged 7–17 years in England), they are associated with significant distress, psychosocial impairment and reduced quality of life (QoL).3 In many cases, symptoms decline in severity during late adolescence and into early adulthood,4 leading to lower rates in adult populations.5
Tourette syndrome and CTDs rarely occur alone, and it is estimated that around 85% of people with TS or a CTD experience one or more co-occurring psychiatric conditions.6 The most common comorbidities are attention deficit hyperactivity disorder (ADHD) and obsessive–compulsive disorder (OCD), both affecting approximately 50% of the TS population across the lifetime.6 Symptoms associated with anxiety disorders, disruptive behaviour and ‘episodic rage’, depression, self-injurious behaviour and autism spectrum disorders are also frequently experienced in this patient group.7,8 The extent of overlap with other diagnostic categories and symptoms has led many to argue that TS belongs to a broader spectrum of neurodevelopmental disorders with shared risk factors and overlapping behavioural, cognitive and social-emotional features.9 Furthermore, additional comorbidities are often associated with greater functional impairment and distress than tics themselves10 and may contribute to difficulties managing tics in daily life. Therefore, tic treatment can be complex, and it is important to take the impact of comorbid conditions on the child and their tics into account.
Current treatment options
To date, in the UK there are still no National Institute for Health and Care Excellence (NICE) guidelines on the management of tics in children and young people (CYP), though evidence-based pharmacological and behavioural therapy (BT) treatments exist,3,11–13 together with consensus and evidence-based treatment guidelines.11,14 For many years, pharmacological treatments were considered the first-line treatments, with randomised controlled trials (RCTs) of both antipsychotics and noradrenergic agents demonstrating effectiveness with small effect sizes (see Hollis et al.3 for a review). However, such drugs are often associated with significant adverse effects such as weight gain and sedation,3 and there has been accumulating evidence for the efficacy of BTs as a viable alternative. Recognising this, recent European guidelines,11 North American guidelines15 and a Health Technology Assessment (HTA) Evidence Synthesis3 all recommend that BT should be offered as the first-line treatment for tics in children and adolescents in a stepped-care approach. These guidelines universally highlight two key BT approaches for their notable evidence base: habit reversal training (HRT) and exposure and response prevention (ERP).11,12 The comprehensive behavioural intervention for tics (CBIT) package, which is based on HRT with additional components, shows similar efficacy to medication.12 However, it is noteworthy that the evidence base for ERP is weaker than that for HRT/CBIT.
Behavioural therapy for tics
Clinical data and background
The effectiveness of BT for reducing tics is now well established,3 with systematic reviews demonstrating a similar magnitude of effect for HRT/CBIT as for pharmaceutical interventions.3,11,12 With numerous larger-scale RCTs having been conducted to date, CBIT in particular is supported by a strong evidence base regarding its efficacy and safety.11
ERP is also endorsed, though ‘to a lesser degree of certainty’11 than HRT/CBIT, owing to its more limited evidence base to date. Systematic reviews of the literature also highlight that psychoeducation, whilst shown to be inferior to BT for tics as a standalone treatment in numerous RCTs, should always be offered as an initial component in BT, regardless of subsequent therapeutic approach.11
Whilst BT models differ in their therapeutic processes, they share similar rationales, theoretical underpinnings and goals. There are various theories highlighting different mechanisms that may be involved in BT for tics. For instance, one theory suggests that HRT/CBIT and ERP work on an underlying principle that motor and vocal tics are linked to a ‘premonitory urge’ (a somatosensory discomfort that occurs before a tic). Tics are then reinforced over time through their association with the premonitory urge, creating an urge–tic cycle. A core aim of BTs for tics is to disrupt the urge–tic reinforcement cycle. This theory also posits that other internal stressors (e.g. emotional distress) and external or situational factors (e.g. environmental stressors, such as noise or social context) may maintain or worsen tics, and so the therapist will also work with patients to address these factors. However, the exact mechanisms involved in BT for tics remain unclear.
Detailed session-by-session guidance on the delivery of HRT/CBIT and ERP can be found in published treatment manuals, but we provide a brief overview of these approaches below. To date there has been no specific research into which BT is preferable for whom or when either HRT/CBIT or ERP in particular may be indicated. From clinical experience alone, Verdellen et al.16 posit that patients with a large number of tics may obtain greater benefit from ERP, as the model addresses multiple (all) tics simultaneously. There is also some clinical or theoretical rationale to applying ERP where there is comorbid OCD, as ERP is the primary evidence-based therapy for OCD symptoms. However, more studies are needed to clarify which BT works best for whom and when. In clinical practice, clinicians often report combining approaches.
Habit reversal training
In HRT, the core aim of therapy is to break the urge–tic–relief cycle by developing alternative or ‘competing’ responses to the premonitory urge. The process of HRT comprises two main components: (1) awareness training, which involves strategies and techniques to increase awareness of both premonitory urges and tics themselves and (2) competing response training, where physically incompatible actions are identified and performed to disrupt/block tic expression. Competing response training only commences for each tic once the individual has developed good awareness of the tic occurring and the ‘tic signal’ preceding it. This process is followed for each tic individually, such that tics are treated one by one in a hierarchy, usually starting with the most bothersome. Working sequentially through each tic in the hierarchy, treatment involves competing response practice and mastery in-session, followed by continued practice at home.
Comprehensive behavioural intervention for tics
Comprehensive behavioural intervention for tics, which is supported by the largest trials to date,17 is simply an extended package of HRT with additional therapeutic components. These include relaxation training, contingency management and functional analyses to identify and address contextual factors that may exacerbate tics, as well as working with families/schools to promote social support. Though there is some uncertainty as to the ‘active’ components of CBIT, several RCTs have consistently demonstrated the superiority of CBIT to psychoeducation-based treatment in young people and adults, with reductions in tic severity maintained at up to 6 months.3,11 An 11-year naturalistic follow-up of the original CBIT trial17 showed reduced tic severity was maintained in those who had received CBIT.18 A recent pilot trial also provided preliminary evidence for the efficacy of a modified form of CBIT with play-based adaptations and significant parent involvement for young children with tics.19
Exposure and response prevention
Exposure and response prevention also aims to break the urge–tic–relief cycle of reinforcement, but instead of developing a competing response to individual tics, the patient learns to tolerate premonitory urges and suppress tic expression altogether. As such, all tics are addressed simultaneously. During therapy sessions, the patient is supported in practicing suppressing tics for prolonged periods (i.e. ‘response prevention’), and strategies are then used to increase ‘exposure’ to the premonitory urge and tic-inducing environmental factors. This typically includes practice focusing on the urge and gradually increasing exposure to situations and activities that typically elicit tics, whilst at all times resisting the urge to tic.
Randomised controlled trial evidence for ERP is more limited, though the available studies suggest that it may be as effective as HRT in reducing tics. One study directly compared HRT with ERP for children with tics and found no statistically significant difference in the reduction of symptoms in terms of tic frequency and a slightly favourable response to ERP on the Yale Global Tic Severity Scale (YGTSS).20 Another study involving both children and adults (n = 43; 7–55 years of age) randomised to either ERP or HRT also demonstrated comparable effects maintained up to the 3-month follow-up.16 Other naturalistic studies have provided supplementary evidence that ERP can be implemented in clinical settings, with comparable effect sizes to those seen in trials to date.11 Though larger-scale trials of ERP-based interventions are needed, these findings highlight the potential for BTs as effective and safe first-line treatments for tics.
Access to BTs for tics
Despite an increasingly clear evidence base and guidelines consistently recommending BT as a first-line treatment approach, access to BTs remains limited. Estimates suggest that only around one in five young people with TS are currently able to access BT for tics in the UK,21 contrasting with approximately 50% receiving medication, despite their more significant risks of adverse effects.12,13 Furthermore, those young people who manage to access BT typically receive four or fewer face-to-face therapy sessions, which is under half the recommended number.21
Research also suggests that families prefer and request better access to BT for tics and are often unsatisfied with current treatment options. Qualitative analysis collated from interviews with 42 young people with TS and a survey of 295 parents of children with TS identified that many families felt health-care professionals were not knowledgeable about TS.21 Specifically, respondents noted the struggle to access limited BT resources, with 76% of parents saying they would like BT to be available for their child, highlighting the need for improved access to behavioural interventions for TS.
Though various factors are likely at play, the ongoing lack of expert therapists trained to deliver behavioural interventions for tics is a considerable barrier to provision. At present, Tourettes Action (https://www.tourettes-action.org.uk) lists fewer than 10 endorsed NHS behavioural therapists for young people with TS throughout the UK. In England, this equates to approximately one therapist to every 10,000 CYP with TS. This lack of provision is compounded by an uneven geographical distribution of therapists, with the majority located in London and surrounding areas. As a result, many families face long-distance travel to national specialist centres for support, which is expensive, disruptive and time-consuming, creating further inequity of access. There is therefore a desperate need for solutions to improve access to specialist treatment for tics, including scaling up provision of BTs.
Digital therapy and internet-based cognitive–behavioural therapy
Over the last decade, internet-based cognitive–behavioural therapy (iCBT) has been developed, which can enable effective and often less therapist-intensive interventions to be delivered over long distances and at reduced cost.22 The potential for internet-delivered treatments to widen access and meet treatment needs more flexibly has been further highlighted throughout the COVID-19 pandemic, with many services increasing their remote and online therapy options through necessity. However, research with service users and staff during this period has also highlighted the importance of appropriate therapist training and technology for online delivery and the need to minimise digital exclusion of the most vulnerable groups.23
The first substantial evidence for iCBT as an effective delivery approach was in the treatment of adults with depression and anxiety disorders, and there is now a large literature indicating that iCBT, in various forms, can be effective and have lasting impact.24–26 Across diagnostic conditions, studies have now shown the efficacy of iCBT compared to no-treatment control conditions and results comparable to face-to-face treatment in terms of symptom reduction,26,27 which could also result in as much as 50% cost savings.26
There is also now a growing literature on digital therapies for mental health difficulties in CYP. Reflecting findings with adult iCBT, effect sizes for short- to medium-term outcomes appear broadly equivalent to those seen in face-to-face treatment.3 Recognising this evidence, NICE now recommend digitally delivered CBT in the treatment of mild to moderate depression in CYP,28 and there has been growing interest in the potential utility of online platforms for a wide range of patient groups and therapeutic approaches; these include iCBT-based programmes for post-traumatic stress disorders (PTSD), OCD and eating disorders, parenting programmes for behavioural support and interventions designed for use with specific physical health or neurodevelopmental problems.22
Therapist-guided iCBT
Research has demonstrated that an important factor in the efficacy and cost-effectiveness of iCBT, mediated by engagement/adherence with therapy, is the provision of therapist guidance. Though self-guided programmes may seem superficially attractive due to their very low implementation costs, data indicate that low adherence is a major drawback.29 Overall, research has shown that therapist-supported platforms perform better in terms of engagement and adherence; moreover, they deliver higher effect sizes and are more cost-effective than pure self-help.25,30 Supporting a low-intensity model of practitioner involvement, even a ‘minimal’ amount of therapist support can be of significant benefit.31 Importantly, service users themselves also report a preference for online interventions that integrate some traditional face-to-face or telephone support.23
One multi-diagnostic, therapist-supported platform of note is the ‘BIP’ [Barninternetprojektet (Child Internet Project; Swedish digital platform)] iCBT programme developed by researchers at the Karolinska Institutet in Sweden. Delivered via a secure, password-protected internet platform that enables the presentation of different treatment content to different paediatric populations, the BIP research platform has been used to deliver iCBT for a range of conditions, including phobias,32 anxiety33 and OCD.34 Similar to models adopted by improving access to psychological therapies (IAPT) in the UK, where graduate mental health workers support adults through manualised, evidence-based iCBT treatment for mild to moderate depression, anxiety and obsessive–compulsive symptoms, the BIP-iCBT treatment content is presented in chapters, like a self-help book, but with interactive materials and videos.
There are some clinical data to support the use of the BIP system for therapist-guided iCBT. A RCT using the BIP system compared participants who received BIP
OCD therapy with a waiting-list control and found a significant reduction in OCD symptoms at 3 months post-treatment.34 Additionally, there were no adverse events (AEs) reported, and participants were generally satisfied with the delivery of treatment, with only 4% stating they would have preferred face-to-face therapy. Qualitative interviews with participants in this trial also demonstrated support for the online delivery of the therapy. Specifically, they noted that iCBT allowed them to control the pace and intensity of the therapy and facilitated self-disclosure, whilst still allowing them to feel supported by a clinician.35 Symptom reduction was also noted in a RCT using the BIP system for anxiety,36 social anxiety disorder37 and OCD,38 and in a pilot study using BIP for specific phobia,32 demonstrating the potential diversity of this platform. Whilst the evidence base for the BIP system has primarily derived from Swedish studies, recent research has demonstrated its generalisability to youth populations in the UK and Australia.39
Remote delivery of BT for tics
Despite the growing literature on iCBT using BIP and other systems, there is little research evidence with regards to the effectiveness of the online treatment of TS. In a recent review of digital health interventions (DHIs), Hollis et al.40 found that the majority of online interventions have been designed to help CYP at risk of developing or with a diagnosis of an anxiety and/or depression, with neurodevelopmental disorders such as TS/CTDs being largely overlooked to date.
Innovations in remote BT for tics to date have primarily focused on video conference delivery, using software such as Skype, with two pilot RCTs providing some support for this approach in CYP.41,42 Himle et al.41 compared video conference-delivered CBIT to traditional face-to-face treatment (8–17 years of age; N =20) and found equivalent reductions in tic severity in both groups, which were sustained at the 4-month follow-up. Ricketts et al.42 compared CBIT delivered over Skype to a wait list control group (N= 20) and reported greater reductions in tic severity in the video conference group. Though both studies were small, ratings from patients indicated high levels of satisfaction with the treatment and a strong therapeutic alliance. Despite some technical challenges (e.g. video/audio disruption, difficulties viewing homework), video conference delivery was generally rated as highly acceptable by the participants.41 Another related pilot RCT also evaluated DVD-supported HRT, where young people (7–13 years of age, N = 44) were guided through a HRT programme with the support of a parent. The results showed the equivalence of DVD-supported HRT and face-to-face treatment, though large drop-out rates make these findings difficult to interpret.
Similarly, there have been two preliminary studies of internet-delivered BT for tics to date, using interactive self-help programmes with therapist support (text/phone). In one pilot study using the BIP system in Sweden, children (8–16 years of age, N =23) were randomised to either an ERP-based or a HRT-based intervention delivered online via the BIP system.43 Participants in both intervention groups showed improvement 3 months after treatment completion in terms of tic-related impairment and parent-rated tic severity; however, only those in the ERP arm showed significant reductions in clinician-rated tic severity as measured with the Yale Global Tic Severity Scale-total tic severity score (YGTSS-TTSS). Furthermore, therapeutic gains were maintained at the 12-month follow-up, and no severe adverse events (SAEs) were reported. Although this was not a study powered to compare efficacy, the findings show that ERP treatment delivered online via a therapist-supported platform such as BIP may be effective in reducing tics and provide some support for an ERP-based format over HRT when delivering BT for tics online. Engagement with and acceptability of the treatment were good, with no dropouts or data loss at any of the assessment points, and 83% of users rated the treatment as good or very good. The researchers in Sweden also noted that the online treatment format demanded less therapist time (approximately 25 minutes/week per participant) than face-to-face BT using primarily text-based support.
Most recently, an Israeli RCT randomised young people (7–18 years of age; N = 45) to either internet-delivered CBIT or a wait list control.44 The results showed a significant reduction in total tic severity (YGTSS-TTSS) in the CBIT group relative to the control condition, with therapeutic benefits maintained at the 6-month follow-up. Again, this study highlighted the potential for considerable time- and cost-saving benefits relative to traditional face-to-face treatment, with therapists spending on average just 7 minutes per participant per week providing telephone support.
Summary and study rationale
There is now reasonable RCT evidence to support the clinical effectiveness of BT for treating tics in CYP. Overall, findings demonstrate the equal effectiveness of BT compared to pharmacological alternatives, with considerably reduced risks of side effects. Whilst most trial data relate to HRT/CBIT, which has the broadest evidence base at present, there are promising clinical and pilot trial data on the acceptability and benefits of ERP and its suitability for adaptation to online delivery. Reflecting the current evidence base, BTs are now recommended as first-line treatment approaches in the treatment of tics in CYP, though there is a need for more research focusing on longer-term outcomes and larger-scale RCT evaluations of ERP.11
Despite growing support for BT in terms of both its evidence base and acceptability amongst service users, access to BT for tics remains very limited, with geographical barriers and a lack of trained therapists noted as key ongoing issues. Qualitative research underlines patient dissatisfaction with the lack of behavioural treatment availability for tics and the need for improved access to treatment. This has led to an increased focus on training, dissemination and adapted treatment delivery in recent years. Particularly in light of the COVID-19 pandemic and the necessity to deliver patient care remotely where possible to maintain existing service provisions, harnessing digital technologies and service innovations is becoming an increasingly important part of NHS policy for the UK.45
There is now a sizeable evidence base supporting internet-delivered treatments or iCBT more broadly, with research showing treatment effects comparable to face-to-face interventions for a growing range of conditions and groups.40 Significant cost-saving potential is indicated, particularly for therapist-guided platforms that bolster better engagement, adherence and efficacy. However, research to date has largely focused on common mental health conditions such as anxiety and depression, with less attention given to online BT for tics or other more ‘specialist’ interventions. Most studies to date have also evaluated treatments outside of the UK, with many being conducted in Sweden using the BIP platform. Whilst a limited number of small RCTs have recently provided preliminary support for internet-delivered BT for tics, larger-scale (adequately powered) RCTs and clarifications on the generalisabilty of internet-delivered BT to the UK population are needed. There is evidence that uptake and use of DHIs (such as BIP TIC) are highly context dependent,46,47 and it would therefore be unwise to assume that a delivery package that works in Sweden will work equally well in the UK.
Study aims and design
The aim of this study was to evaluate the clinical and cost-effectiveness of a therapist-guided, parent-assisted ERP
BT intervention for tics in young people with TS/CTDs. The interventions were delivered remotely via the BIP technical platform. Building on previous evidence from a Swedish pilot trial,43 the study compared an online ERP-based behavioural intervention and online tic-related psychoeducation. Our primary hypothesis was that remotely delivered, therapist-supported ERP-based BT would be superior to an active comparator intervention of online tic-related psychoeducation in reducing tic severity.
The study design was a single-blind, parallel-group, randomised controlled superiority trial, with an internal pilot and strict ‘stop–go’ progression criteria. The primary clinical outcome (tic severity) was measured via blind-assessed, clinician-rated YGTSS-TTSS.4 A range of secondary clinician-, parent- and child-completed outcome measures were also implemented, addressing tic-related impairment, behavioural and emotional difficulties and global improvement. Measures of QoL, service use and treatment credibility and satisfaction were also obtained. Details of all primary and secondary measures, including their psychometric properties, can be found in the ‘Trial methods’ section.
The overarching aim of this study was to address the BT treatment gap for young people with tic disorders in a cost-effective manner that can be feasibly scaled up to provide widespread and equitable access to evidence-based treatment for tics across the NHS. In particular, the study aimed to add to the currently limited evidence base relating to online BT for tics by implementing an adequately powered RCT of an ERP-based, therapist-supported online intervention compared with an appropriate (psychoeducation-based) active control intervention. As the therapist role in guided iCBT is to encourage uptake and adherence to the programme, not to deliver highly specialised therapy, the skill set required is easily acquired, as demonstrated by the successful low-intensity IAPT programme, which uses graduate mental health workers to facilitate use of self-help materials by patients. Hence, if the acceptability and efficacy of the proposed therapist-guided behavioural intervention for tics is demonstrated in this trial, it should be feasible to roll it out and adopt it at scale in the NHS, IAPT
BT for CYP with tics.
