Abstract
<title>Abstract</title> <p> <bold>Background</bold> Psychiatric comorbidities are common in children and adolescents with Tourette’s disorder (TD) and may have a greater impact on quality of life (QoL) than tics. However, the relative contribution of different comorbidities and the potential moderating effect of sex remain insufficiently understood. This study examined the associations between psychiatric comorbidities and QoL in a large European pediatric sample with TD. <bold>Methods</bold> Data were obtained from 667 children and adolescents with TD (aged 3–16 years) participating in the European Multicenter Tics in Children Studies (EMTICS). QoL was assessed using the parent-reported KINDL-R. Linear mixed-effects models were used to examine associations between QoL and categorical psychiatric comorbidities (obsessive-compulsive disorder [OCD], attention-deficit/hyperactivity disorder [ADHD], oppositional defiant disorder [ODD], autism spectrum disorder [ASD], and emotional disorders), continuous symptom severity measures, and the number of comorbid disorders. Sex moderation effects were also explored. <bold>Results</bold> All comorbid psychiatric disorders were associated with lower QoL. In multivariable analysis, emotional disorders showed the strongest independent association with reduced QoL. These associations remained significant after adjustment for tic severity. Similar findings were observed in analyses using dimensional symptom measures. QoL decreased progressively with the increasing number of psychiatric comorbidities. Sex moderated the associations between tic severity, OCD symptoms, and ASD symptoms and QoL, with stronger negative associations observed in girls than in boys. <bold>Conclusions</bold> Psychiatric comorbidities, particularly emotional disorders, are strongly associated with impaired QoL in pediatric TD, beyond the effects of tic severity. Assessment and treatment of comorbid psychopathology may be critical for improving QoL, especially among girls and those with multiple comorbid conditions. </p>