Primary objective: To determine the clinical efficacy of BIP TIC (Andrén et al., 2019; a therapist-guided and parent-guided, internet-delivered behavioural intervention for Tourette's Disorder (TD) and Persistent (Chronic) Motor or Vocal Tic Disorder (PTD), for reducing tic severity (as measured by the primary outcome variable Yale Global Tic Severity Scale [YGTSS] Total Tic Severity Score [TTSS]) in children and adolescents with TD/PTD, compared with a control intervention (therapist-guided and parent-guided internet-delivered education on tics).~Secondary objectives: To establish the 12-month durability of the treatment effects, and to assess the cost-effectiveness of BIP TIC, compared with therapist-guided and parent-guided internet-delivered education on tics, from a societal perspective.~Type of trial: Single-blind parallel-group randomised controlled superiority trial.~Trial design and methods: All potential participants are initially screened via the telephone, or in some cases at the clinic. This is followed by an inclusion assessment conducted either at the clinic or via the videoconference software Zoom. Participants who are eligible and have consented will be randomised into one of two trial arms. In the experimental arm, participants receive 10 weeks of therapist-guided and parent-guided internet-delivered exposure and response prevention (ERP). In the control arm, participants receive 10 weeks of therapist-guided and parent-guided internet-delivered education on tics. Participants will complete outcome measures at baseline, mid-treatment (3 and 5 weeks post-baseline), post-treatment (10-weeks post-baseline) and 3, 6 and 12 months post-treatment. To allow for holidays or periods of sick leave, it is possible to extend the duration of the treatment from 10 to a maximum of 12 weeks (of which only 10 weeks will include therapist support). In these cases, the listed time frames in the Outcome Measures section will be extended with the equivalent number of weeks.~The primary outcome variable is the Total Tic Severity Score (TTSS) of the Yale Global Tic Severity Scale (YGTSS), and the primary endpoint is the follow-up 3-months post-treatment. For secondary outcomes, see section below. Follow-up assessments will be conducted at the clinic or via Zoom videoconference software, in both cases complemented with online questionnaires.~Planned trial sites: All assessments and delivery of treatment will be administrated from a single site in Stockholm, the Child and Adolescent Psychiatry Research Center. Several collaborating counties all across Sweden will assist on referring potential participants to the Stockholm site for inclusion in the trial.~Sample: 220 participants.~Statistical methodology and analysis: Data will be analysed using a pre-specified intention-to-treat statistical analysis plan.
The purpose of this trial is to evaluate the clinical efficacy, 12-month durability, and cost-effectiveness of BIP TIC - a therapist-guided and parent-guided internet-delivered behavioural intervention for children and adolescents with Tourette's Disorder and Persistent (Chronic) Motor or Vocal Tic Disorder.