Internet-based ERP therapy improved response in Tourette syndrome

Therapist-supported internet-based exposure and response therapy led to higher response rates and was cost effective for young persons with Tourette syndrome or chronic tic disorder compared with internet-delivered tic education.

“Clinical guidelines recommend behavior therapy as a first-line treatment for Tourette syndrome and chronic tic disorder, but its availability is very limited,” Per Andren, PhD, of the Center for Psychiatry Research, Karolinska Institute in Stockholm, Sweden, and colleagues wrote in JAMA Network Open.

Andren and fellow researchers developed an internet-delivered form of exposure and response prevention (ERP) therapy for children and adolescents with Tourette syndrome (TS) or chronic tic disorder (CTD) and sought to examine its feasibility and efficacy.

The study was a single-masked, parallel-group, superiority-randomized clinical trial with nationwide recruitment and conducted at a research clinic in Stockholm. From an initial pool of 615 eligible individuals, 221 participants aged 9 to 17 years met diagnostic criteria. Participants were randomly assigned on a 1:1 basis to receive either 10 weeks of therapist-supported internet-delivered ERP therapy for tics (n = 111) or to therapist-supported internet-delivered education for tics (n = 110). The primary outcome was change in tic severity from baseline to the 3-month follow-up, as measured by the Total Tic Severity Score of the Yale Global Tic Severity Scale (YGTSS-TTSS). Treatment response was operationalized as a score of 1 (“Very much improved”) or 2 (“Much improved”) on the Clinical Global Impression-Improvement Scale. Enrollment began in April 2019 and ended in April 2021, with data analyzed between October 2021 and March 2022.

Results showed 216 of 221 participants (97.7%) provided necessary primary outcome data. Among randomly assigned participants (152 boys; mean age, 12.1 years), tic severity improved significantly, with a mean reduction of 6.08 points on the YGTSS-TTSS in the ERP therapy group (mean [SD] at baseline, 22.25 [5.6]; at 3-month follow-up, 16.17 [6.82]) and 5.29 in the comparator (mean [SD] at baseline, 23.01 [5.92]; at 3-month follow-up, 17.72 [7.11]).

Intention-to-treat analyses showed both cohorts improved similarly over time (interaction effect, 0.53; 95% CI, 1.28 to 0.22). Significantly more participants were classified as treatment responders in the ERP therapy group (51 of 108) than in the comparator group (31 of 108) at the 3-month follow-up (OR = 2.22; 95% CI, 1.27-3.9). ERP therapy resulted in more treatment responders at little additional cost compared with structured education. The incremental cost per quality-adjusted life-year gained was below the Swedish willingness-to-pay threshold, at which ERP therapy had a 66% to 76% probability of being cost effective.

“Implementation of the digital ERP intervention into regular health care would increase availability of treatment for young people with TS or CTD,” Andren and colleagues wrote.

In a related editorial, Tamara Pringsheim, MD, of the department of clinical neuroscience, psychiatry, pediatrics and community health sciences at the University of Calgary, and John Piacentini, PhD, of the Semel Institute for Neuroscience and Human Behavior at UCLA, wrote, “From a broader perspective, the findings from this study provide further support for the acceptability and efficacy of behavioral treatments for tic disorders ... this is not by any means to say that medication no longer plays a role in the treatment of TS.”