Design
The present study is a pilot study, based on a small patient sample (N = 14) of children aged 9–14 years of age. Representatives of the Dutch national patient organization (among which author LPLB) were actively involved in this project, from start to finish, including developing the design of the study. This included continuous reviewing of the research process and the content of the project from the patients’ perspective by ‘experts by experience’, developing and performing workshops on coping strategies and parent support meetings during the treatment. Patients and their parents were recruited between June 2018 and December 2018 by the Dutch Tourette Association and the outpatient clinic De Bascule in Amsterdam. Tic severity and other inclusion and exclusion criteria were determined by an experienced child psychiatrist.
Inclusion criteria were: (a) youths aged 9–17 years, (b) diagnosed with TS or CTD, using diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, 5th edition [30], (c) with at least moderate tic severity as indicated by a YGTSS total score > 13 (or > 9 for children with motor or vocal tics only).
Exclusion criteria were: (a) behavioral treatment for tics in the past 12 months, (b) pharmacological treatment for tics that has not been stable the for the past 6 weeks or with planned changes during study participation, (c) poor mastery of the Dutch language, (d) IQ < 75, (e) serious physical disease, (f) substance abuse, (g) suicidality, (h) psychotic disorders, (i) severe autism spectrum disorders (ASD) or attention deficit hyperactivity disorder (ADHD) problems, which would hamper group functioning, (j) poor group functioning, as reported by child and/or parents during intake. Since TS is seldom seen without comorbidities [1], co-occurring ADHD, OCD, other anxiety disorders or mood disorders were included, unless the disorder required immediate treatment or change in current treatment.
Before the start of the therapy weeks, four co-therapists (psychologists with 2.5–5 years of experience) were trained by experts in behavioral therapy (ERP) for tic disorders. A patient advisory board, with parents and young adult patients, that gave feedback on the project, was installed during the study preparation phase and before treatment. Based on this feedback, some adaptations were applied to the program and data gathering. That is, we took into account their advice to guard against possible unrealistic expectations of the treatment outcomes (such as a complete disappearance of the tics) and possible misunderstanding of psycho-education, and to check the need for more care or support after the program, and the need for more tools to exercise at home. Therefore, we clarified the psycho-education for parents and added questions to the treatment satisfaction questionnaires. Also, the advisory board strongly recommended to build a positive and safe group atmosphere from the start, without children having to answer difficult questions about their problems. Therefore, we decided to collect the outcome measures at home, instead of during the treatment program at the outpatient clinic.
The children participated in one of two outpatient groups at De Bascule, Academic Centre for Child and Adolescent Psychiatry in Amsterdam, in September 2018 and February 2019, including, respectively, 6 and 8 children per group. Therapy sessions and psycho-education group meetings were performed by three highly experienced behavioral therapists, who are experts on tic disorders and ERP, assisted by three co-therapists, for training purposes. Coping workshops and parent meetings were developed and performed by experienced patient representatives of the Dutch Tourette Association.
Intervention
Tackle your Tics is a group therapy program based on evidence-based ERP [31]. ERP aims to interrupt a postulated cycle of negative reinforcement between a premonitory urge and a subsequent tic by learning patients to tolerate premonitory urges while suppressing tics for prolonged time periods [17, 32]. To optimize exposure, urges are provoked, for instance by asking the patient to imagine situations with many tics, talking about tics and introducing urge-eliciting objects (e.g., exciting games). The therapist functions as a coach, encouraging the patient to improve his/her achievements. ERP usually consists of 12 weekly individual sessions (12 × 45 ERP-minutes = 540 min). In the Tackle your Tics program, ERP is provided in a brief, intensive format of 4 days: 3 consecutive days and 1 booster day after a week (4 × 135 ERP minutes = 540 min, see Table 1). The program was offered in groups of 6–8 children, to facilitate motivation and peer support. Apart from the overall group format, during Tackle your Tics, ERP exercises were trained in smaller subgroups of 2–3 children, in which children assisted each other (by timing, registering tics and encouraging). When needed, a child could train a specific exercise for a while individually with a therapist. On day 3, children went outside of the treatment center (e.g., riding a bike, being among other people, playing games) with the therapists to learn to generalize their newly learned skills. Also, several supporting and motivating activities were added to enhance motivation and fun, and reduce drop out.
Table 1 Tackle your Tics content Coping strategy workshops
Daily coping strategy workshops were given by trained young adult patients (experts-by-experience who are also educational professionals) from the national patient association. They taught the children how to cope with their symptoms in a positive ‘mind-set’. In accordance with a large European patient survey [14], this support did not focus on tics only but also on other symptoms, comorbidities and positive characteristics and strengths.
BT-Coach
BT-Coach is a mobile application that helps children to practice the ERP exercises, learned in the therapy sessions, in the absence of a therapist [33]. Through audio feedback, the app takes over the coaching role of the therapist during homework exercises. When a tic is expressed, the child registers this by pressing ‘Tap for a Tic’. BT-Coach stimulates the child to stop the next tic and work on new records. An improved version is currently being developed, in which data collection is optimized and calculations are possible. In this study, the BT-Coach was introduced during the first training days and sometimes used in the therapy sessions when children liked this. The app was used to motivate the children to continue with the exercises at home. On the third and fourth training day, the app was used as part of a relapse prevention plan (‘keep the tics away plan’). No data were collected for this study or in medical files.
Parent meetings
Parent meetings were in part attended by a therapist who explained the ERP treatment, discussed expectations and how parents could help their child gaining control over the tics during and after treatment. In addition, an experienced parent counsellor of the patient association offered parents the opportunity to exchange experiences in the parent group and find emotional support. At the end of each day, therapists had short individual meetings with the child and its parents to evaluate the day and ERP exercises, give advices on how to handle tics at home and answer possible questions.
Psycho-education
Children as well as their parents learned about premonitory sensations (‘tic alarms’), tic triggers, difficult moments and practicing at home.
Relaxation
The Tackle your Tics program contained several short relaxation trainings, focusing on breathing techniques, as well as playtime and fun activities.
Measurements
Assessments were performed pre-treatment (T0, 1 week before treatment) and post-treatment (T1, 1 week after treatment: (that is: a week after the ‘booster’ day, to be able to measure the preceding week’s tic severity, after the booster session, by the YGTSS) and at the follow-up assessment (T2, 2 months after treatment).
Demographic variables/patient characteristics (gender, age, cultural background, parents’ educational level, comorbidities) were derived from medical files and a semi-structured interview (Anxiety Disorder Interview Schedule; ADIS, parent version) [34].
Feasibility was assessed by: (1) attendance/drop-out rates, (2) standardized treatment satisfaction forms (parent and child version, with a rating on five-point Likert scale, ranging from 1 = very negative/not helpful at all to 5 = very positive/helpful and also by questions in open format), specifically designed for this study, to measure satisfaction about the treatment program as a whole, the program components and individual experiences or recommendations, (3) interviews/evaluations with the patient advisory board and caregivers, to understand the needs and concerns of participating parents and children.
Tic severity (key outcome) was assessed by the semi-structured interview Yale Global Tic Severity Scale; YGTSS [35]. The global score (response range 0–100) is composed of an impairment score (0–50) and a total tic score (0–50). The total tic score, used as our primary outcome, adds the total motor tic score (0–25) to the total vocal tic score (0–25). We defined a 25% tic reduction as a positive response [36].
Quality of life was measured by the Gilles de la Tourette Syndrome Quality of Life Scale for children and adolescents; C&A-GTS-QOL [37], which is a 27-item disorder-specific patient-reported scale for the measurement of health-related quality of life in patients with TS (range 27–135).
Premonitory urges were assessed by the Premonitory Urges for Tics Scale; PUTS [38]. This is a nine-item self-report questionnaire which assesses tic-related feelings and sensations (premonitory urges) (range 9–36).
Emotional/behavioral functioning was measured by the Child Behavior Checklist; CBCL [39, 40]. This 113-item parent-report questionnaire assesses emotional and behavioral problems, covering 8 dimensions (raw scores were analyzed).
Statistical analyses
To avoid chance findings, only the key outcome (tic severity) and our main secondary outcome (quality of life) were statistically tested. Other measurement outcomes were reported descriptively. To test whether there were changes in the main outcomes scores, from pre- to post-assessment to follow-up, repeated-measures ANOVAs were performed on the key outcome (tic severity) and our main secondary outcome (quality of life). The effect sizes were calculated in SPSS as Partial Eta Squared. A nonparametric test (related-samples Friedman’s two-way analyses of variance by ranks) was used as an extra control. If the parametric test and the nonparametric test lead to the same conclusion, any violations of assumptions apparently have little influence or are absent.
For each variable, complete case analysis was performed, to avoid imputation of missing data. A p value of < 0.05 was considered significant. To test for multiple comparisons, we did a Bonferroni correction (p < 0.025). SPSS Version 25 was used for the analyses (IBM SPSS Statistics for Windows, Version 25.0. Armonk, NY: IBM Corp). As a sensitivity analysis, we reanalyzed our data with including the patient who was excluded because of poor group functioning.