Conclusions

2017 has again seen a rise in publications on TS and reflects the increased interest this field receives, both from clinicians and researchers devoted to this disorder but also from adjoining fields, given the substantial psychopathology associated with tics. 
One important question raised is the natural course of TS and the rate of (non-)remission. Recent data suggest that the optimistic outlook prevalent with regard to tic severity when gliding from adolescence into adulthood might not be completely justified. Here, large longitudinal studies are warranted, also to better understand the prognostic factors associated with tic remission or persistence. The fate of comorbidities also needs to be better understood, even though data have begun to emerge. We also still face important delays in the diagnosis of TS, and we need to deal with the recently demonstrated increased suicide risk in this condition, which underlines that tic disorders are far from benign.
Of note, there is a rise in computational models of TS which provide important leads to understanding its pathophysiology and will likely fuel more targeted treatment approaches for tics. In the therapy field, 2017 has mainly seen studies centered on well-known pharmacological targets such as the dopaminergic system; however, new antidopaminergic medications were studied or came to the market in 2017, and increasing data supports existing off-label prescription practices. Behavioral therapy continues to emerge as a main pillar of tic treatment, with an improved understanding of its mechanisms and response factors. In the surgical field, deep brain stimulation for severe TS cases continues to draw interest ; in particular, target choice, length of stimulator programming for optimal outcome, and closed-loop systems are under active investigation. 
Overall, the field is active and burgeoning. Breakthroughs are to be expected in the upcoming years, especially with regard to large-scale efforts in the field.
 

Competing interests

KJB participated in clinical trials supported by Neurocrine Biosciences, Inc., and Psyadon Pharmaceuticals, Inc.

Grant information

This work was supported in part by the U.S. National Institutes of Health (NIH), grant R01 MH104030. The authors confirm that the funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.