Diagnostic agreement in assessing FTLB was examined by asking eight experts in diagnosing and treating patients with tics to evaluate videos from 24 adults and diagnose them with either functional tics, primary tics or both \citep{Rigas2023}. The diagnostic agreement was fair based on phenomenology alone, and increased to moderate when additional clinical information was provided. The diagnostic distinction between primary and functional tics is shown to be difficult in the absence of clinical information.
Two groups have reported about long-term prognosis in patients with FTLB \cite{Nilles2024,Prato2022a}\cite{Prato2022a} found that at 12 month follow up both tics as well as anxiety significantly improved while OCD and depressive symptoms persisted. \cite{Nilles2024} observed meaningful improvement of FTLB over a period of observation of 12 months indicating that they overall have good prognosis. 

Comorbidities

A survey in children with tic disorders led to a predictive model for "behavioral problems" (based on the CBCL) \citep{36732748}.
\citet{Sadeh2023} examined the presence of depressive symptoms in a cohort of 85 children and adolescents with chronic tic disorders (CTD), aged 6-18 years, with the Child Depression Inventory. In total, 21% had depressive symptoms and the presence of depressive symptoms was correlated with the presence of comorbid OCD and/or ADHD. Furthermore, symptoms of depression moderated the correlation between tic-related impairment and tic severity. Therefore, the authors suggest that it is important to screen and treat depression in children with CTD. 
The presence of depression and anxiety were assessed in several other studies. \citet{Isaacs2023} examined a population of 120 adult patients with CTD with several scales as part of routine care. Symptoms of anxiety were more common than depressive symptoms. Anxiety, depressive and OCD symptom severity were significantly associated to each other, but not to tic severity. In a systematic review and meta-analysis including twelve studies from 1997-2022,  the prevalence of anxiety and depression was found to be 36.4 % and 53.5 % respectively \citep{Abbasi2023}.
Impulsivity and attention were compared in 14 patients with TS, 16 patients with OCD and 28 healthy controls \citep{Koenn2023}. Both patients with OCD and patients with TS showed significant deficits in attention via self-assessment. The severity of tics was correlated strongly positively with attentional impulsivity. The authors conclude that a detailed interpretation of the various tools for measuring impulsive behavior is necessary.
Topic of sleep problems in TS was explored by \cite{Colreavy2023}. Interestingly enough, they found that sleep patterns in children with TS were more impacted by the pandemic than in typically developing children. \cite{Keenan2024} adopted naturalistic, longitudinal approach to examine sleep in children with TS. Importantly, TS children were compared to healthy controls. In addition to clinical assessment, authors attributed variety of scales and measured sleep-wake cycle with wrist actigraphy. As a result, it has been demonstrated that children with TS spent significantly more time in bed, have increased sleep onset latency, reduced sleep efficiency, lower subjective sleep quality, whereas sleep time was comparable. In contrast to clinical observations, self-reported tic severity was not related to increased sleep onset latency. In addition, 83.33% of children with TS fulfilled the diagnostic criteria for a sleep disorder highligting importance for screening for sleep difficulties in clinical routine. 
 
Kurvits et al. \cite{Kurvits2023} investigated investigated the prevalence of prevalence of compulsive sexual behaviors and paraphilic interests in patients with tics. In contrast to previous reports, these comorbidities were found with the same rate as in general population. There was also no association with use of antipsychotics. ADHD was risk factor for paraphilic interests and compulsive sexual behaviors in TS.  
 
TS Study Group from Denmark \cite{Andersen2023} published results of longitudinal study in which correlates of subtance use of pediatric patients with TS. Presence of ADHD and lower socioeconomic status of the guardian predicted higher risk for tobacco smoking, while coexisting OCD was a protective factor. The same group \cite{Tygesen2023} compared fine motor skills in children with TS, their healthy siblings and matched healthy controls. No difference between these three groups were found.