43 - Pharmacological treatments

Pharmacological treatments

614 The Maudsley® Prescribing Guidelines in Psychiatry CHAPTER 5 Tics and Tourette’s syndrome in children and adolescents Transient tics occur in ­5–­20% of children. Tourette’s syndrome (TS) occurs in about 0.7% of children and adolescents and is defined by persistent motor and vocal tics. As many as 65% of individuals with TS will have no tics or only very mild tics by adult life. Tics wax and wane over time and are variably exacerbated by external factors such as stress, inactivity and fatigue, depending on the individual. Tics are about two to three times more common in boys than girls.1 Functional tic disorders (involuntary physical movements, often related to anxiety) have also been described in recent years.2 These are typically seen in teenage girls. Detection and treatment of comorbidity Comorbid OCD, ADHD, ASD, depression, anxiety and behavioural problems are more prevalent than would be expected by chance, and often cause the major impairment in people with tic disorders.3 These comorbid conditions are usually treated first before assessing the level of disability caused by the tics. Education and behavioural treatments Most people with tics do not require pharmacological treatment. Education is ­crucial for the individual with tics, their family and the people they interact with, especially at school (Figure 5.2). Treatment aimed primarily at reducing tics is warranted if the tics cause distress to the patient or are functionally disabling. Behavioural interventions have been found to be effective with similar effect sizes to antipsychotic medication.4,5 Habit reversal, comprehensive behavioural ­intervention for tics and exposure and response prevention are the behavioural treatments of choice.6 Pharmacological treatments Studies of pharmacological interventions in TS are difficult to interpret for several reasons: ■ ■There is a large inter-­individual variation in tic frequency and severity. Small, randomised studies may include patients who are very different at baseline. ■ ■The severity of tics in a given individual varies markedly over time, making it difficult to separate drug effect from natural variation. ■ ■The bulk of the literature consists of case reports, case series, open studies and underpowered, randomised studies. Publication bias is also likely to be an issue. ■ ■A high proportion of patients have comorbid psychiatric illness. It can be difficult to disentangle any direct effect on tics from an effect on the comorbid illness. This makes it difficult to interpret studies that report improvements in global functioning rather than specific reductions in tics. ■ ■Large numbers of individuals attending clinics with TS appear to use complementary or alternative therapies, with the majority reporting benefits and up to half finding