As an experienced clinician who has seen tics and habits in your patients come and go, you may be surprised by the amount of concern parents express about them. At times, it seems, and may be, that the parent’s attention to the habit actually keeps it going! This does not always mean that the child keeps doing the habit to aggravate the parent, as parental correction may amp up the child’s anxiety, which may make the habit worse.
As with other parent concerns, both empathizing with their worry and providing evidence-based information is helpful in relieving their distress.
Habits are complex behaviors done the same way repeatedly. Habits can have a strong protective effect on our lives and be a foundation for success when they ensure that we wash our hands (protection from infection), help us know where the keys are (efficiency), or soothe us to sleep (bedtime routines).
Tics are “involuntary” (meaning often, but not always, suppressible), brief, abrupt, repeated movements usually of the face, head, or neck. More complex, apparently meaningless movements may fall into the category of stereotypies. If they last more than 4 weeks, are driven, and cause marked dysfunction or significant self-injury, they may even qualify as stereotypic movement disorder.
It is good to know that repeated behaviors such as thumb sucking, nail/lip biting, hair twirling, body rocking, self biting, and head banging are relatively common in childhood, and often (but not mostly) disappear after age 4. I like to set the expectation that one habit or tic often evolves to another to reduce panic when this happens. Thumb and hand sucking at a younger developmental age may be replaced by body rocking and head banging, and later by nail biting and finger and foot tapping.
Even in college, habits are common and stress-related such as touching the face; playing with hair, pens, or jewelry; shaking a leg; tapping fingers; or scratching the head. Parents may connect some of these to acne or poor hygiene (a good opening for coaching!) but more importantly they may be accompanied by general distress, anxiety, obsessive-compulsive symptoms, and impulsive aggressive symptoms, which need to be looked for and addressed.
Stereotypies occur in about 20% of typically developing children (called “primary”) and are classified into:
• Common behaviors (such as, rocking, head banging, finger drumming, pencil tapping, hair twisting),
• Head nodding.
• Complex motor movements (such as hand and arm flapping/waving).
Habits – including nail biting, lip chewing, and nose picking – also may be diagnosed as stereotypic movement disorders, although ICD-10 lists includes them as “other specified behavioral and emotional disorders.”
For both conditions, the behavior must not be better accounted for by a compulsion, a tic disorder, part of autism, hair pulling (trichotillomania), or paroxysmal dyskinesias.
So what is the difference between motor stereotypies and tics (and why do you care)? Motor stereotypies begin before 3 years in more than 60%, whereas tics appear later (mean 5-7 years). Stereotypies are more fixed in their pattern, compared with tics that keep shifting form, disappearing, and reappearing. Stereotypies frequently involve the arms, hands, or the entire body, while tics involve the eyes, face, head, and shoulders. Stereotypies are more fixed, rhythmic, and prolonged (most more than 10 seconds) than tics, which are mostly brief, rapid, random, and fluctuating.
One key distinguishing factor is that tics have a premonitory urge and result in a sense of relief after the tic is performed. This also means that they can be suppressed to some extent when the situation requires. While both may occur more during anxiety, excitement, or fatigue, stereotypic movements, unlike tics, also are common when the child is engrossed.
Tics can occur as a side effect of medications such as stimulants and may decrease by lowering the dose, but tics also come and go, so the impact of a medication can be hard to sort out.
One vocal or multiple motor tics occurring many times per day starting before age 18 years and lasting more than 1 year are considered chronic; those occurring less than 1 year are transient. Chronic multiple motor tics accompanied by vocalizations, even sniffing or throat clearing, qualify as Tourette syndrome. The feared component of Tourette of coprolalia (saying bad words or gestures) is fortunately rare. These diagnoses can only be made after ruling out the effects of medication or another neurological condition such as Sydenham’s chorea (resulting from infection via group A beta-hemolytic streptococcus, the bacterium that causes rheumatic fever) or PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections).