Background Exposure and Response Prevention (ERP) is a form of behavioural therapy for tics; however, its effectiveness remains uncertain. We aimed to evaluate the effectiveness of internet-delivered, therapist-supported, and parent-assisted ERP for treatment of tics in children and young people with Tourette syndrome or chronic tic disorder.Methods This multicentre, parallel group, single-blind, randomised controlled trial was conducted across two study sites in England. Participants were recruited via 16 patient identification centres, two study sites in England (Nottingham and London), or online self-referral. Eligible participants were aged 9-17 years, had Tourette syndrome or chronic tic disorder, had not received behavioural therapy for tics in the past 12 months or were about to start, and had a Yale Global Tic Severity Scale (YGTSS) Total Tic Severity Score (TTSS) of more than 15 or more than 10 if they had only motor or vocal tics. Patients were excluded if they had started or stopped medication for tics within the past 2 months; had current alcohol or substance dependence, psychosis, suicidality, anorexia nervosa, or suspected moderate to severe intellectual disability; or presented an immediate risk to self or others; or the parent or carer was unable to speak, read, or write in English. Eligible patients were randomly assigned (1:1) by masked outcome assessors to receive 10 weeks of online, remotely delivered, therapist-supported ERP or psychoeducation (active control). Outcome assessors, statisticians, health economists, the trial manager, and the chief investigator were masked to group allocation. Patients were not directly informed of their allocation, but this could be established from the content once treatment commenced and the patients were not, therefore, considered masked to treatment. The primary outcome was YGTSS-TTSS 3 months after randomisation, and analysis was done in all randomised patients for whom data were available for each timepoint and outcome. Safety analysis was by intention to treat. Longer term follow-up is ongoing. This trial is registered with ISRCTN (ISRCTN70758207) and ClinicalTrials.gov (NCT03483493).

Background: Little is known about the long-term effectiveness of behavioural therapy for tics. We aimed to assess the long-term clinical and cost-effectiveness of online therapist-supported exposure and response prevention (ERP) therapy for tics 12 and 18 months after treatment initiation. Methods: ORBIT (online remote behavioural intervention for tics) was a two-arm (1:1 ratio), superiority, single-blind, multicentre randomised controlled trial comparing online ERP for tics with online psychoeducation. The trial was conducted across two Child and Adolescent Mental Health Services in England. Participants were recruited from these two sites, across other clinics in England, or by self-referral. This study was a naturalistic follow-up of participants at 12-and 18-month postrandomisation. Participants were permitted to use alternative treatments recommended by their clinician. The key outcome was the Yale Global Tic Severity Scale Total Tic Severity Score (YGTSS-TTSS). A full economic evaluation was conducted. Registrations are ISRCTN (ISRCTN70758207); ClinicalTrials.gov (NCT03483493). Results: Two hundred and twenty-four participants were enrolled: 112 to ERP and 112 to psychoeducation. The sample was predominately male (177; 79%) and of white ethnicity (195; 87%). The ERP intervention reduced baseline YGTSS-TTSS by 2.64 points (95% CI: À4.48 to À0.79) with an effect size of À0.36 (95% CI: À0.61 to À0.11) after 12 months and by 2.01 points (95% CI: À3.86 to À0.15) with an effect size of À0.27 (95% CI -0.52 to À0.02) after 18 months, compared with psychoeducation. Very few participants (<10%) started new tic treatment during follow-up. The cost difference in ERP compared with psychoeducation was £304.94 (À139.41 to 749.29). At 18 months, the cost per QALY gained was £16,708 for ERP compared with psychoeducation. Conclusions: Remotely delivered online ERP is a clinical and costeffective intervention with durable benefits extending for up to 18 months. This represents an efficient public mental health approach to increase access to behavioural therapy and improve outcomes for tics.