CHAPTER 15
Tourette Syndrome and Other
Tic Disorders
Tics are sudden, repetitive, stereotyped movements (motor tics) or ut-
terances (phonic or vocal tics). They are either involuntary or partly
voluntary in response to a premonitory ‘urge’. Simple motor tics (such
as blinks, grimaces or shrugs) and simple phonic tics (such as grunts, sniffs
or barks) are clearly purposeless. Complex motor tics (such as brushing
hair back, spinning round, touching things) and complex phonic tics (such
as words or phrases) may seem more purposeful but are out of context.
Tics commonly occur in bouts and characteristically vary in intensity from
week to week and from month to month. They can briefly be suppressed,
are often better during sleep or an absorbing activity, and usually worsen
with either stress or relaxation. The stress of being teased or stared at
because of tics can make the tics worse, setting up a vicious cycle.
Classification
While tics can be transient and all of the same type, Tourette syndrome
involves chronic motor and vocal tics: more than one type of motor tic
plus at least one type of phonic tic, lasting for over a year and starting
before 21 years of age. Other disorders recognised by DSM-IV and ICD-10
are ‘chronic motor or vocal tic disorder’ and ‘transient tic disorder’.
Most child and adolescent psychiatric disorders can only be diagnosed
when the characteristic symptoms result in significant distress or social
impairment – a useful way of distinguishing between normal variation
and disorders likely to require clinical services. The ‘distress or impairment’
requirement was present in the DSM-IV definition of tic disorders but is
absent from both DSM-IV-R and ICD-10. A disadvantage of this omission
is that many individuals can be diagnosed as having tic disorders even
though they have no need for services.
Child and Adolescent Psychiatry, Third Edition. Robert Goodman and Stephen Scott.
©c2012 Robert Goodman and Stephen Scott. Published 2012 by John Wiley & Sons, Ltd.
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