Chronic tic disorder (CTD) may have a huge impact on life quality. Habit Reversal Training (HRT) and Exposure Response Prevention (ERP) are effective therapeutic modalities. This study examined the effect of a combined treatment using both HRT and ERP in children and adolescents with CTD. The treatment outcome was examined as an individual treatment compared to a group setting. There was no control group. The study examined both acute outcome and outcome at one year of follow-up. Predictive factors for treatment outcome were evaluated.

Chronic tic disorder (CTD) may have a huge impact on life quality. Habit Reversal Training (HRT) and Exposure Response Prevention (ERP) are known to be effective therapeutic modalities. Little is known about the effect of group therapy, the effect of combining HRT and ERP training, and of the long-term effect of treatment. This study therefore wanted to examine the effect of a combined treatment using both HRT and ERP in children and adolescents with CTD. The participants were randomized to treatment either in groups or in an individual setting. The parents were included in the training programme. The participants were asked to fulfill questionnaires concerning anxiety, mood, life quality, their thoughts about tics and the experienced premonitory urge. Furthermore, they were interviewed with the semistructured interview Yale Global Tic Severity Scale (YGTSS).

Data was obtained from patient files as to examine possible predictors of both acute and long-term treatment effects. The evaluators were a specialized psychologist and a child and adolescent psychiatrist with several years of experience in diagnosing, evaluating and treating tic disorders. A random sample of 10% were audiotaped and evaluated by another rater with extensive experience and expertise in the use of the YGTSS. The evaluator was not blinded to the treatment allocation, yet not involved in the treatment of the patient, and blinded to any previous evaluations

Inclusion Criteria:

• A primary diagnosis of either Tourette syndrome or a chronic motor/vocal tics disorder
• Moderate or greater severity corresponding to a total score on the Yale Global Tic Severity Scale (YGTSS) higher than 13 (higher than nine if only motor or vocal tics were described)

Exclusion Criteria:

1. Disorders that required immediate treatment

   • psychotic disorder
   • primary severe depression
   • suicidal ideation or attempts
   • primary severe anorexia nervosa

2. Disorders that makes participation difficult

   • IQ below 70
   • a life-time diagnosis of pervasive developmental disorder

3. Treatment with HRT or ERP during the last six months.

In accordance to Danish law, personal data cannot be shared

Evaluations of treatment response were made by an independent evaluator who was not blinded to the treatment allocation, yet not involved in the treatment of the patient, and blinded to any previous evaluations. The evaluators were a specialized psychologist and a child and adolescent psychiatrist with several years of experience in diagnosing, evaluating and treating tic disorders. A random sample of 10% were audiotaped and evaluated by another rater with extensive experience and expertise in the use of the YGTSS