The association between tic medication therapy and psychiatric comorbidities among patients with Tourette syndrome: A national population-based study in Taiwan

Prevalence of nail biting and its chronological relationship with tics in child and adolescent outpatients with Tourette syndrome: a single-centre, retrospective observational study

OBJECTIVE

To evaluate the prevalence of nail biting in child and adolescent outpatients at a single institution and the chronological relationship between nail biting and tics in patients with Tourette syndrome (TS) with or without attention-deficit hyperactivity disorder (ADHD).

DESIGN

Retrospective observational study.

SETTING

Teaching hospital in Taiwan.

PARTICIPANTS

All participants were aged 4-18 years, including 535 patients with TS, 230 patients with provisional tic disorder and 1460 patients without neurological or psychiatric disorders (controls).

OUTCOME MEASURES

Presence of nail biting, starting age for nail biting and starting age for motor and/or vocal tics.

RESULTS

Nail biting was more commonly observed in patients with TS (56.6%) than in patients with provisional tic disorder (27.4%) or controls (15.0%), regardless of sex (all p<0.020). Nail biting was also more common in patients with TS with ADHD than in those without (75.0% vs 47.6%; p<0.001), but the starting age was significantly later in those with concomitant ADHD than without (5.3 vs 3.8 years; p<0.001). In patients with TS, the onset of nail biting occurred earlier than that of tics, regardless of ADHD status.

CONCLUSION

Nail biting was more prevalent and occurred earlier than tics in patients with TS, regardless of ADHD status, in the study population.

Challenges in the Diagnosis and Assessment in Patients with Tourette Syndrome and Comorbid Obsessive-Compulsive Disorder

Tourette syndrome (TS) is characterized by the presence of vocal and motor tics with an onset in childhood. In almost 80% of patients psychiatric comorbidities coexist, particularly, attention deficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD) or behavior (OCB), depression, anxiety, rage attacks, and self-injurious behaviour (SIB). In this review, we discuss current state of the art regarding diagnosis and assessment of tics and OCD in patients with TS as well as challenges related to differential diagnosis between tics and OCD-related phenomena based on a systematic literature search. While in most cases clinical symptoms can be easily classified as either tics or OCB/OCD, some phenomena lay on the frontier between tics and compulsions/obsessions. For example, compulsions may resemble tics and, vice versa, sequences of motor tics may be misdiagnosed as compulsions. Accordingly, the terms "compulsive tics" and "cognitive tics" have been introduced. The most common and typical OCD symptom in patients with TS are "just right" phenomena, which also may show an overlap with tics, since patients may perform tics repeatedly until this feeling is achieved. Similarly, repetitive behaviors in patients with TS may manifest in a more "tic-like" or a more "OCD-like" type. Furthermore, SIB shows similarities with both tics and OCD. Until today, it is unclear how to classify this symptom best, although from most recent research a closer relationship between SIB and tics is suggested. In this review, in addition, we illustrate differences of the clinical spectrum of OCD in patients with TS compared to those with "pure OCD" without tics. To assess tics, the revised version of the Yale Global Tic Severity Scale (YGTSS-R) should be used, while for the assessment of OCD, the Yale Brown Obsessive Compulsive Disorder Scale (Y-BOCS) is recommended. Finally, we briefly summarize treatment strategies for tics and OCB/OCD in patients with TS.