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Most cases of TS are
thought to be "mild," meaning that the individual
does not seek treatment and/or does not experience
significant interference in their life from their
tics. If tics become problematic, you may wish to
consider treatment options (treatment options are
discussed in the article, "Treatment
of Tics and Tourette's
Syndrome,"
also on this web site.
In the first years
after tics first emerge, many people report that
the waxing periods tend to worsen from one waxing
cycle to the next. The child may experience more
tics and/or more severe tics over time, and there
seems to be a tendency for things to get worse
before they get better. The good news is that for
many individuals, the tics will ease up
significantly or go into remission in the teen
years. A report by Leckman et al. (1998) suggests
that tics seem to reach their peak severity between
the ages of 10 - 12 in the majority of cases, and
that by age 18, half of the children may be
virtually tic-free, with other children showing
significant improvement.
In another study on
changes over time, Burd, Kerbeshian, et al. (2001)
followed 39 out of 73 patients who had been
diagnosed with TS as children in 1984-1985. They
reported that symptom severity decreased by 59%,
global functioning improved by 50%, and the average
number of comorbidities (other conditions also
present) decreased by 42%. Similar to findings by
Leckman, they reported that 44% of the patients
were essentially symptom free at follow-up; only
22% were on medication as adults. In their sample,
improvement in males was more variable than
improvement in females, but overall, males
demonstrated more improvement than females.
Patient reports of
symptoms improvement are often subjective, and a
study by Pappert, Goetz, et al. (2003) suggests
that many adults report being tic-free when they
actually still have tics. In this study, the
investigators compared videotapes of 31 adults with
TS to the same individuals' videotapes during
childhood.They found that motor tic severity
significantly decreased by adulthood, as did
objective measures of overall tic disability. In
contrast to previous studies that had relied on
subjective reports, these investigators found that
90% of the adults still had tics. As a group, the
adults were somewhat inaccurate in their
self-assessment in the sense that those who
reported having tics did, in fact, display tics,
but 50% of those who reported being tic-free also
displayed objective evidence of tics. The
investigators suggest that tics may persist into
adulthood more than studies using subjective
reporting might suggest, but that when adults
report improvement or being tic-free, it's probably
because of a significant improvement in motor tic
severity.
While the majority of
individuals seen in clinics appear to have a
significant remission or improvement in tics, there
are people who do not show improvement with age or
whose tics worsen in adulthood. As an example,
Pappert et al. (2003) computed a "global tic
impairment" score based on five tic factors (number
of body areas with tics, motor tic frequency, motor
tic severity, phonic tic frequency, phonic tic
severity) and compared the childhood global tic
impairment scores to the scores of the same
individuals as adults. For their sample, they found
that that 10 of the 31 adults in their study had
worse objective global tic disability scores as
adults. There was a reliable and moderately strong
correlation between the severity of objective
global tic impairment at childhood and the severity
of objective global tic impairment in adulthood.
Taken together, the data suggest that:
- motor tic
severity tends to decrease in the majority of
cases over time, and
- children who have
severe global tic impairment are somewhat likely
to have severe global tic impairment as
adults
A number of adults
have reported that either their TS re-emerged after
decades of being tic-free or that they are
beginning to suffer adverse physical effects after
years of severe ticcing. Unfortunately, while most
clinicians seem to be aware of this, no one seems
to be doing any long-term research to address these
compelling adult needs and only a handful of
published articles even refer to the re-emergence
of TS after decades of quiet.
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Although there have
been very few studies that have looked at this
question in community-based studies, and there are
certainly children and adults who have TS without
any other conditions, a significant percentage of
TS patients seen in clinical settings also have
symptoms of other disorders or conditions. It is
important, however, to keep this caveat in mind: we
really don't know what percentage of all people
with TS will have other problems or disorders
because what we see in clinical settings may
represent only the more severe end of the spectrum
and not the majority of individuals with TS.
As you read more
about Tourette's, you will probably encounter terms
like "co-morbid" or "associated," so we will begin
by defining those terms as they are used on this
web site. We say that two conditions are "comorbid"
when we want to indicate that two conditions are
present in the same individual. We say something is
an "associated disorder" when there appears to be a
significant probability that the two conditions
will occur together at a higher rate than you would
expect by chance.
When I first began
talking to people about TS, I realized that when
some people would say "That's a symptom of my son's
TS," they weren't talking about tics but about
features or symptoms of disorders such as Attention
Deficit Hyperactivity Disorder or
obsessive-compulsive symptoms. So to decrease
confusion in our communication, in 1991, I
introduced the term "TS+" to refer to
individuals who have TS plus features of one or
more other disorders such as Attention Deficit
Hyperactivity Disorder (ADHD), Obsessive-Compulsive
Disorder (OCD), anxiety, self-injurious behaviors,
anger or rage outbursts, or depression, to name but
some of the conditions that may be associated with
or frequently comorbid with TS. The goal was to
help people remember that not everything may be a
tic of TS, and that the child may have other
conditions that may be responsible for any
impairment they are experiencing.
"TS+" is not a
technical or diagnostic term, but rather a
convenient way to remind ourselves that there is
often other things affecting a child who has been
diagnosed with TS. This is particularly evident
when we examine school functioning. In the vast
majority of cases I've dealt with over the years,
it is seldom the tics that are the child's or
teen's biggest problem.
Unfortunately, and
despite my best efforts to remind people not to
attribute everything to TS when it may be due to
something else, all too many people continue to
describe people with TS as having a variety of
problems that may not be due to TS at all, but
rather to some other condition. For example, one
publication from the National Tourette Syndrome
Association suggested that TS was linked with
Central Auditory Processing Disorder (CAPD), and
yet there is not one study that shows any direct
association between TS and CAPD. Such imprecise
writing does not further our understanding of TS.
It is one thing to say that children with TS and
Attention Deficit Hyperactivity Disorder may be
more likely to have CAPD, but it is quite another
thing to say that children with TS are more likely
to have CAPD.
So, what other
disorders tend to be associated with or frequently
comorbid with TS? The answer depends on whom you
ask and whether the research is based on a clinical
sample or a community-based sample. That said, the
majority of clinical settings report that a
significant percentage of individuals who have TS
also have obsessive-compulsive behaviors and
Attention Deficit Hyperactivity Disorder. Mood
disorders such as depression and Bipolar Disorder
are also commonly reported. Some researchers,
including David Comings, MD, have suggested that
there are many other disorders that are also linked
to TS, including sleep disorders, oppositional
defiant or conduct disorder, "rage attacks,"
anxiety disorders, alcohol and substance abuse
problems, and autism, to name but some. Other
researchers have reported either some support or
total disagreement with Dr. Comings' findings.
[Note: some of these conditions are discussed
in other articles on this web site.]
In a community-based
study of school children that employed direct
interviews and standardized rating scales for 1596
children, Kurlan and his colleagues found that OCD,
ADHD, separation anxiety, overanxious disorder,
simple phobia, social phobia, agoraphobia, mania,
major depression, and oppositional defiant behavior
occurred significantly more frequently in the
children who had tics compared to their non-tic
peers [Kurlan, Como, Miller, et al., 2002].
But are all of these conditions really associated
with tics, or is it the case that some of them are
just associated with each other? For example, could
it be that you don't find oppositional defiant
behavior unless there is also ADHD? There is much
that we don't know about what is truly associated
with TS and what conditions are only present if
there is ADHD or OCD in the presence of TS.
Additional research is clearly needed to help
identify patterns.
Other research also
suggests that children with Tourette's tend to be
shorter and weigh less than non-TS children with
ADHD, and problems with conduct disorder or
self-injurious behavior may be more common in those
children with TS who are in the lowest quartile of
height and weight. [Zelnik et al, 2002].
Some studies, such as
that by Kwak et al. (2003) indicate that migraine
headaches are significantly more common in those
with Tourette's than would be expected based on the
general rate of migraine headaches in the
population. The presence of migraine headaches did
not appear to be linked with any
obsessive-compulsive factors.
Is there any
indication that children or adults with TS are more
likely to have personality disorders or other
problems? Unfortunately, there has been very little
"hard" research on this topic, although adults with
TS who are seen in clinics generally present
because of problems in anger management. In one of
the few studies that looked at the question of
personality disorders, Robertson et al. (1997)
compared adult clinic patients with TS to
undergraduate students and hospital staff. They
reported that the TS patients were significantly
more likely to have a personality disorder, and
that many of the patients had more than one
personality disorder. Their data indicate that
about half of the adult TS patients had Borderline
Personality Disorder and were also significantly
more likely to have other personality disorders:
Avoidant, Depressive, Obsessive-Compulsive,
Paranoid, and Passive-Aggressive. However, one
cannot tell from their study whether the
personality disorder was causally linked to the
Tourette's or rather to a comorbid condition -- or
whether it was the result of having been
misunderstood during their childhood and
adolescence.
A more recent study
by Eapen et al. (2004) found that for adult
patients with TS seen in clinical settings, male
patients were significantly more likely to have an
earlier onset of TS and to have had birth
complications. Consistent with many other published
clinical reports, they found that obsessive
compulsive behaviors were positively correlated
with presence of ADHD and self-injurious behaviors.
Their analyses of adult psychopathology in their
sample supported the hypothesis that there is a
high occurrence of anxiety, depression and
obsessionality in adult TS subjects seen in
clinical settings.
So where does that
leave parents of newly diagnosed children? From my
perspective, parents of newly diagnosed children
need to be aware that:
- these other
disorders generally don't emerge at the same
time as the TS if they're going to emerge at
all,
- a child can have
features of another disorder without meeting all
the criteria for diagnosis of another disorder,
and
- when push comes
to shove, the research on whether something is
or is associated with TS or comorbid with TS is
not as important as understanding what is going
on with your child and what you can do about it.
If your child is
struggling at home or in school or socially and the
behavior or symptom doesn't really appear to be a
tic, then be curious about what else might be going
on, and find outthe other conditions described on
this web site.
Those interested in
the comorbidity issues for scientific reasons or
curiosity will be interested in finding out about
the ongoing multi-site study known as TIC. As the
data come in from sites all over the world, our
understanding of what percentage of patients may
have different comorbid problems -- or NO comorbid
problems -- increases. So far, it seems that those
individuals who have TS-only generally do not
experience significant functional impact in their
daily lives, although they may still need
understanding, support, and
accommodations.
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