Tics in autism spectrum and in intellectual disability

Tourette syndrome (TS) is a neuropsychiatric and a neurodevelopmental disorder often presenting alongside other neurodevelopmental conditions such as attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), learning difficulties, and dyspraxia. TS shares genetic and neurobiologic features with ASD and ADHD, suggesting common underlying mechanisms. Recent diagnostic frameworks such as the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, APA, 2013) allow for multiple co-occurring diagnoses, reflecting the complex overlap among neurodevelopmental disorders. Whilst there are several studies stating high rates of TS in ASD and vice versa, the data about the nature of tics in those with ASD is sparse; nevertheless, it shows that they are probably not different in nature to tics present in TS. Tics in individuals with ASD can be diagnostically challenging due to overlapping motor behaviors like stereotypies. Intellectual disability (ID) further complicates tic identification, given communication difficulties and co-occurring behaviors. A pragmatic, needs-focused clinical approach is recommended, emphasizing prioritisation of presenting problems over an accumulation of diagnostic labels. This strategy facilitates targeted interventions where needed. In children with ID, differentiating between tics and stereotypies is important to avoid inappropriate management.