When Tics and Autism Meet: Phenomenology, Severity, and Treatment Patterns

Tic disorders frequently co-occur with neurodevelopmental conditions, including autism spectrum disorder (ASD). However, the impact of ASD on tic phenomenology, severity, and treatment patterns remains incompletely understood.

To compare clinical characteristics, tic phenomenology, severity, and treatment patterns in individuals with tic disorders with and without comorbid ASD.

We conducted a cross-sectional analysis of 535 participants from Calgary Child and Adult Tic Disorders Clinical Registries. Tic severity was assessed using the Yale Global Tic Severity Scale (YGTSS). Comorbidities, tic phenomenology, and pharmacological treatments were recorded. ASD and non-ASD groups were compared using t-tests and chi-square tests.

Mean age at tic onset was 6.79 years; 73.3% were male, and 9.2% had ASD. ASD was associated with higher rates of complex motor (arm 20.4% vs 9.9%; hand 24.5% vs 13.9%) and vocal tics (phrases 12.2% vs 3.5%; palilalia 20.4% vs 8.3%; blocking/stuttering 16.3% vs 6.2%) compared with non-ASD participants (all P < 0.05), with similar overall severity. ASD was also associated with higher rates of ADHD (81.6% vs 44.7%) and greater use of guanfacine, aripiprazole, risperidone, methylphenidate, and dextroamphetamine compared with non-ASD participants (all P < 0.05). In multivariable analysis, ASD was independently associated with lower tic-related impairment (β = -4.49, 95% CI -8.46 to -0.51; P = 0.027).

Comorbid ASD in tic disorders is associated with higher rates of complex motor and vocal tics, while severity is similar to non-ASD. Lower tic-related impairment may reflect communication differences. Comorbid symptoms influenced treatment supporting the need for individualized management.