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Updated: Oct 19, 2026
Generating Acute and Chronic Experimental Models of Motor Tic Expression in Rats
Published on: May 27, 2021
A systematic review to characterize functional tic-like behaviors
Joseph B Gary1, Jacob S Shaw1,2, Joseph F McGuire1
1Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
Background:
Functional tic-like behaviors (FTLBs) have emerged as a prominent clinical presentation within the context of the COVID-19 pandemic. Although FTLBs share phenomenological overlap with Tourette Syndrome and other tic disorders (collectively Tourette Syndrome, TS), evidence suggests that differences exist in demographics, phenomenology, clinical course, psychiatric comorbidity, and response to intervention. Given the rapid rise in the incidence of FTLBs-along with their complex clinical presentation-we provide a systematic review and integrated synthesis of the extant literature.
Methods:
We conducted a systematic review following PRISMA guidelines. PubMed and PsycINFO databases searches were completed in June 2026, using terms related to functional tics and TS. Inclusion criteria were English-language studies reporting clinical data on FTLB with sample sizes of 8 or greater. Case reports, non-human studies, and commentaries were excluded. Thirty-nine studies were included. Data were extracted on demographics, phenomenology, clinical course, psychiatric comorbidity, and treatment responsiveness. Since multiple reports originated from the same data repositories, information was synthesized qualitatively by study sample and conceptual domain.
Results:
The results of our review suggest that FTLBs predominantly affect adolescents and young adults and exhibit a strong female predominance-with higher than anticipated representation of gender-diverse individuals. Compared with TS, the onset of FTLB symptoms was abrupt and characterized by complex motor movements and vocalizations that cause functional impairment. While there is a considerable overlap between FTLBs and TS, there were distinctions in patterns of psychiatric comorbidities. Pharmacological and cognitive behavioral therapy (CBT) provided some benefit for individuals with FTLBs, but the therapeutic target of these interventions was not specified.
Conclusions:
While sharing some similarities, FTLBs have a distinct clinical presentation from TS. There is some evidence to inform treatment approaches, but findings are complicated by the retrospective nature of most extant reports. Future research is essential to characterize longitudinal trajectories, underlying mechanisms, and evaluation of targeted interventions in randomized clinical trials.
