Social behavior and comorbidity in children with tics

To examine the characteristics of children with coexisting tics and autism spectrum disorder and determine if children with tics have deficits in social behavior.

Descriptive study of children referred for tics over 18 months. Parents completed the Social Responsiveness Scale and the Social Communications Questionnaire; children screening positive on these measures were evaluated for autism spectrum disorder. Characteristics of children who were diagnosed with both disorders are described. Subscales scores on the Social Responsiveness Scale for children with tics without a comorbid autism spectrum disorder were compared. The relationship between a comorbid diagnosis of attention deficit hyperactivity disorder and autism spectrum disorder symptoms was explored using logistic and linear regression.

One hundred and fourteen children were evaluated. Children with a tic disorder and autism spectrum disorder had significantly higher rates of comorbid attention deficit hyperactivity disorder (P = 0.005), rage attacks (P = 0.006), and oppositional defiant disorder (P = 0.007) than children without autism spectrum disorder. Mean tic severity and treatment rates did not differ between groups. Mean subscale scores on the Social Responsiveness Scale for children without autism spectrum disorders fell into the clinically significant range for autistic mannerisms only. All Social Responsiveness Scale scores were significantly increased by an attention deficit hyperactivity disorder diagnosis (P < 0.0001).

Children referred for assessment of tics should be screened for autism spectrum disorders. There is a subgroup of children with multiple neuropsychiatric comorbidities who suffer from social dysfunction and autistic mannerisms outside of an autism spectrum disorder diagnosis.