Objective Tourette syndrome (TS) is a developmental condition characterised by tics and associated with other psychiatric diagnoses, in particular obsessive-compulsive disorder (OCD) and attention-deficit hyperactivity disorder (ADHD). Despite the availability of behavioural and surgical options, pharmacotherapy remains the most common management option for patients with TS. The possible effects of psychiatric co-morbidities upon prescribing practices in adults with TS have not been examined in the literature to date.

Method We conducted a retrospective chart review of all consecutive adult patients with TS who agreed to take part in clinical research conducted at the specialist TS clinic between 2009 and 2013. Types of pharmacological agents, as well as DSM-validated diagnoses and clinician-rated measures of tic severity (Yale Global Tic Severity Scale), were examined across different patient groups defined by the presence of psychiatric co-morbidities.

Results Of 162 adults with TS, 88 (54.4%) had “pure” TS, 34 (21.0%) had a co-morbid diagnosis of OCD, 26 (16.0%) had co-morbid ADHD and 14 (8.6%) had both co-morbidities. Overall, 106 patients (65.4%) were on pharmacological treatment. The presence of co-morbid ADHD or OCD was significantly associated with use of pharmacotherapy (p=.02), more strongly than total tic severity (p=.04). Although there was no significant association between co-morbidity type and pharmacological class used, serotonergic agents were most commonly prescribed in patients with TS+OCD (41.2%) and alpha-2 agonists in patients with TS+ADHD (23.1%).

Conclusion The majority of adult patients attending specialist TS clinics require pharmacotherapy. The presence of co-morbid OCD and ADHD, followed by tic severity, are the main factors associated with use of pharmacotherapy and can play an important role in the choice of medication class.