Tourette's syndrome: update.

Tourette's syndrome is a widely misunderstood chronic disorder that develops in childhood and is usually lifelong. It is characterized by waxing and waning of involuntary motor and phonic tics. The features and differential diagnosis are discussed in this paper. The estimated prevalence rate of Tourette's syndrome, 0.05%, implies that this disorder is not rare. The reasons for diagnostic confusion are outlined, and the genetic and neurotransmitter features discussed. The management of Tourette's syndrome has become more effective with the availability of at least two psychoactive drugs, haloperidol and pimozide. Although the cause of this syndrome is thought to be organic, these drugs and their adverse effects are best known to psychiatrists. Psychiatric and multidisciplinary intervention is often necessary because of the frequent association of psychosocial problems, cognitive and learning difficulties, and aggravation of the symptoms by stress. The understanding of Tourette's syndrome will probably increase significantly with the advent of the newer imaging techniques and the rapid progress of research in the neurosciences.