Clinical course of Tourette syndrome

Abstract

Objective: Tourette syndrome (TS) is a childhood-onset neuropsychiatric disorder characterized by multiple motor and vocal tics lasting at least a year in duration. Children with TS often experience comorbid conditions such as obsessive-compulsive disorder (OCD) and attention-deficit disorder. The goal of this article was to review the long-term clinical course of tics and comorbid conditions in children with TS.

Method: We conducted a traditional literature search to locate relevant articles regarding long-term outcome and prognosis in TS and tic disorders.

Results: Tics typically have an onset between the ages of 4 and 6 years and reach their worst-ever severity between the ages of 10 and 12 years. On average, tic severity declines during adolescence. By early adulthood, roughly three-quarters of children with TS will have greatly diminished tic symptoms and over one-third will be tic free. Comorbid conditions, such as OCD and other anxiety and depressive disorders, are more common during the adolescence and early adulthood of individuals with TS than in the general population.

Conclusion: Although tics are the sine qua non of TS, they are often not the most enduring or impairing symptoms in children with TS. Measures used to enhance self-esteem, such as encouraging strong friendships and the exploration of interests, are crucial to ensuring positive adulthood outcome in TS.

Fig. 1

Clinical course of tic severity in childhood. Plot of average tic severity in a cohort of 36 children from ages 2 to 18. Tics typically have an onset between ages 4 and 6 years, reach their worst-ever between ages 10 and 12, and then decline in severity throughout adolescence. (Adapted with permission from Leckman et al. [9].) ARRTS=Annual rating of relative tic severity. In the ARRTS, parents rate tic symptoms of their children on a six-point ordinal scale [absent (0), least severe, mild, moderate, severe, and most severe (6)].

Fig. 2

Adulthood tic severity in 82 children with significant childhood tic symptoms. Adulthood tic severity class is defined by Yale Global Tic Severity Total Tic Score (YGTSS): no tics (YGTSS: 0), minimal tics (YGTSS: 1–9), mild tics (YGTSS: 10–19), moderate or greater tics (YGTSS: ≥20). By contrast, all individuals had moderate or greater severity tics in childhood. Less than 5% of individuals reported having worse adulthood tics than in childhood.

Fig. 3

Course of Tic Severity and Comorbid Conditions in TS. The width of the bars schematically show relative burden of illnesses at a particular age. Adapted from JF Leckman 2000 [40].