compared a group of patients with FTLB (n=32) with a very large sample of patients with tics (n=1032). A number of previously reported characteristics of FTLB could be replicated: older age of onset, higher prevalence of females, and higher rate of obscene and socially inappropriate behaviors. Interestingly, patients with FTLB had significantly lower rates of psychiatric comorbidities typically seen in TS such as ADHD and OCD. Phenotypic differences between  patients with FTLB (n=53) and tics (n=200) were also analyzed by a group of researchers from Denmark (Andersen et al. 2023).  Patients with FTLB were found to have more complex symptoms, were older at symptom onset, were more frequently females, and had less frequently a positive family history for tics. As a new finding, they reported that patients with FTLB had more family members with psychiatric disorders and had more common a history of trauma preceding the onset.
 
\cite{Firestone2022} published report about cluster of cases of FTLB that surged in the school in Minnesota. This most likely was the case of what was previously described in the literature of the mass sociogenic illness \cite{M_ller_Vahl_2021a}. Eight students of the same school developed FTLB, all of them were female at the age of 15-17. Following previous line of research, all of them had history of depression or anxiety.
 As noted above, patients with TS are not immune from also developing functional tic-like behaviors (FTLB). This association is not surprising, as for example pseudoseizures are more common in people with epilepsy. \citet{M_ller_Vahl_2023} present data on 71 TS patients whom they also diagnosed with FTLB. A majority (56%-79%) had psychological features common in people with other functional symptoms, and about a third of them had a history of other medically unexplained symptoms; these findings suggest that the cause of FTLBs is likely similar to that of other functional neurological symptoms. The authors comment that their ability to identify a fairly large sample of TS+FTLB suggests that clinicians faced with treatment-resistant symptoms in TS should consider whether the symptoms are FTLB rather than tics.
Finally, international group of experts published results of the largest, so far, group of patients with FTLB seen in multiple centers across the globe \cite{Martino2023}. 294 patients with FTLB were included, vast majority of whom were adolescents and young adults (97%) and 87% were females. 70% of patients presented with rapid symptom progression, spontaneous remission was noted in 20% of cases. From the phenomenological perspective, 85% demonstrated complex movements and 81% complex vocalizations. Only one fifth had preexisting tic disorder, 66% had comorbid anxiety, around 30% depression, followed by autism found in 24% and ADHD in 23%. Again, high number (60%) reported exposure to social media. 
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.
The topic of sleep problems was explored in two studies. Colreavy et al. (2023)   \cite{Colreavy2023}. found that sleep pattern in children with TS are more impacted by the pandemic than in typically developing children. Using a naturalistic, longitudinal approach Keenan et al. (2024)  \cite{Keenan2024} found that children with TS spend significantly more time in bed, have increased sleep onset latency, reduced sleep efficiency, lower subjective sleep quality compared to healthy controls,, whereas sleep time is comparable. In contrast to clinical observations, self-reported tic severity was not related to increased sleep onset latency. In addition, more than 80% of children with TS fulfilled diagnostic criteria for a sleep disorder highlighting the importance for screening for sleep difficulties in clinical routine. 
Kurvits et al.    \cite{Kurvits2023} investigated the prevalence of compulsive sexual behaviors and paraphilic interests in adults  with chronic tic disorders. In contrast to previous reports, these symptoms were found with the same rate as in the general population. There was also no association with the use of antipsychotics. ADHD was a risk factor for paraphilic interests and compulsive sexual behaviors.   
  The Danish TS Study Group (Andersen et al. 2023)  \cite{Andersen2023}  published the results of a longitudinal study investigating substance use in pediatric patients with TS. Comorbid ADHD and lower socioeconomic status of the guardian predicted higher risk for tobacco smoking, while coexisting OCD was a protective factor.
 Tygesen et al.  \cite{Tygesen2023}  compared fine motor skills in children with TS with their healthy siblings and matched healthy controls, but failed to demonstrate any differences between these three groups.