Autism in children and young people with functional tic-like behaviours: a retrospective cross-sectional study

Functional tic-like behaviours (FTLB) are characterised by multiple, complex, vocal and/or motor tics, typically with adolescent onset. Emerging research highlights neurodevelopmental conditions as vulnerability markers for FTLB development, yet no studies have specifically studied this subgroup. This study (1) investigates the prevalence of autism in young people with FTLB, (2) compares demographic and clinical features between patients with FTLB with and without autism and (3) examines the diagnostic accuracy of the Development and Well-Being Assessment (DAWBA) in identifying autism in this patient group.

The study comprised 63 children presenting to the Great Ormond Street Hospital Tic Service between August 2020 and May 2022 with an FTLB diagnosis. Demographic and clinical variables were determined through retrospective chart review.

In the FTLB sample, 69.8% were diagnosed with autism and 37% had Tourette syndrome, both much higher than in the general population. Results indicated that young people with FTLB with and without autism have similar rates of reported impairment, as measured by the Strengths and Difficulties Questionnaire, but those with autism had higher rates of co-occurring attention-deficit/hyperactivity disorder (ADHD, 61%) and specific learning disorders (27%). The DAWBA demonstrated poor sensitivity (ranging from 0.09 to 0.26) in predicting likelihood of autism in this group.

There is a high prevalence of autism in patients with FTLB. Those with FTLB and autism may be more likely to have ADHD and specific learning disorder compared with those with FTLB alone. Better clinical screening for autism is essential in patients with FTLB as DAWBA is insufficient.