Effectiveness of behaviour therapy for children and adolescents with Tourette syndrome and chronic tic disorder in a real-world setting

Background: Treatment guidelines recommend behaviour therapy (BT) as the first-line intervention for patients with Tourette syndrome (TS) and chronic tic disorder (CTD). The efficacy of BT has been documented in randomised controlled trials (RCTs), but it is unclear to what extent these results are generalisable to real-world clinical settings, and whether the therapeutic gains are maintained long-term. Methods: In this naturalistic study, 74 young people with TS/CTD (aged 6 to 17) received BT (including psychoeducation, exposure with response prevention, habit reversal training or a combination of these treatments) at a specialist clinic in Stockholm, Sweden. Data were routinely collected at baseline, post-treatment, and at 3-, 6-, and 12-month follow-ups. Measures included the clinician-rated Yale Global Tic Severity Scale (YGTSS) and the Clinical Global Impression – Improvement scale (CGI-I), amongst others. Results: Tic severity and tic-related impairment (as measured by the YGTSS) improved significantly after treatment, with large within-group effect sizes (d=1.03 for the YGTSS Total Tic Severity Score, and d=1.37 for the YGTSS Impairment Score). At post-treatment, 57% of the participants were classified as treatment responders according to the CGI-I. Both tic severity and tic-related impairment continued to improve further through the follow-up, with 75% of the participants being rated as responders 12 months after the end of treatment. Significant improvements were also observed across a range of secondary measures. Conclusions: BT is an effective and durable treatment for young people with TS/CTD in a real-world clinical setting, with effects comparable to those reported in RCTs.