Abstract Aim. Personal and family mental health histories of youth with functional tic-like behaviours (FTLB) and/or tics (TS) were compared. Method. This is a cross-sectional study with between-group analysis of 127 patients aged 4–17 years referred to a tic service between 2019 and 2022 who were diagnosed with FTLB, TS, or co-occurring FTLB and TS. Co-occurring psychiatric and neurodevelopmental conditions in the personal and family history of cases collected prospectively were recorded as per standard care. Post-hoc analysis was undertaken to explore findings of interest. Results. Later tic onset (13 years vs. 5 years) and increased comorbid psychiatric disorders (> 78% vs. 51%) in the FTLB versus TS groups, support the European Society for the Study of Tourette Syndrome (ESSTS) criteria for clinical diagnosis of FTLBs. Anxiety, depression and autism were more prominent in FTLB groups. 35% of the FTLB group had an ADHD diagnosis. Family history of tics is significantly more likely in the TS groups, while family history of anxiety was most prominent in the TS+FTLB group. Post hoc analysis indicated that in FTLB with co-occurring ADHD, the majority of ADHD (56%) was picked up following FTLB presentation, with missed ADHD diagnoses mainly in girls. Discussion. Patterns of difference in mental health and family mental health exist between TS and FTLB supporting ESSTS diagnostic criterion for FTLB. FTLB is associated with anxiety, depression and autism. ADHD is present in 35% of FTLB even without TS, and if this is a replicable finding, suggests a treatable vulnerability factor in FTLB.
Liang et al. (Tue,) studied this question.