Tics are classified as a motor disorder under the neurodevelopmental disorder category of the DSM (the manual clinicians use to diagnose mental disorders). Tics are typically a childhood disorder, only occasionally seen among adults.

*See also: Tourette’s Syndrome

What are tics?

A tic is a repetitive gesture or body movement a person feels compelled to perform. They are defined as sounds or movements that arise “intermittently and unpredictably” in everyday situations. Some examples of tics include:

  • Shoulder shrugging
  • Chronic blinking
  • Clearing one’s throat
  • Tapping on things
  • Grunting or sniffling
  • Rubbing
  • Touching a certain item or body area repeatedly
  • Head bobs or weaving
  • Hand clapping
  • Flexing or stretching
  • Abrupt jerks of the head or limbs
  • Facial movements, such as mouth movements or grimacing
  • Coughing
  • Making noises (animal sounds or repetitive vocalizations)

A person may also exhibit complex tics, which are larger, more sophisticated expressions:

  • Specific touching or tapping sequences
  • Twirling
  • Jumping or hopping
  • Arm straightening
  • Pulling at clothes
  • Imitating another person’s actions or gestures (such as needing to cough upon hearing someone else cough).

The Yale Global Tic Severity Scale is used to assess the symptoms of different tic disorders in children and adolescents ages 6 to 17.

Not all tics are outwardly visible. Some, such as stomach tensing or toe scrunching, may be known only to the person performing such actions. Tics are semi-voluntary reactions–not entirely within a person’s control, but not entirely involuntary either, since a person can learn to suppress such urges.

The severity of tics can vary from hour to hour and changes over the course of days, weeks, or months. Symptoms will typically wax and wane, becoming more severe at certain times and less severe at others. The frequency of tics can increase with stress, boredom, fatigue, or strong emotions. Symptoms usually grow worse when a child is sick or ill. Relaxation may also lead to an increase in the frequency of tics. Heavy concentration and absorption in an activity, meanwhile, will typically decrease their severity.

Many people confuse tics with fasciculations–small twitches of the upper or lower eyelid, for example. These twitches are not classified as tics because they have a different origin (electrical twitches in a few fibre bundles of muscle that don’t necessarily involve the brain), and do not involve the whole muscle. These spasms are strictly involuntary and harder to see. Conversely, tics can be missed and misdiagnosed because they mimic another disorder such as asthma.

What is it like to experience a tic?
It starts with a premonition of the tic, what is referred to as the premonitory urge. This is best described as a buildup of tension that culminates in an irresistible feeling, much like the urge to sneeze, yawn, or scratch an itch. This buildup in tension is often connected to the tic itself. For example, a person may feel a buildup of tension in their shoulders, leading them to shrug. Or they may experience a tingling sensation in the throat that leads to the urge to clear one’s throat. Younger children are typically less aware of the premonitory urge and have less impulse control in their brain, which is why they typically have a tougher time controlling tics.

How common are tics?

It’s estimated that around 1% of the population has a tic disorder, with varying degrees of severity. Tics are more common among children, with 5% of kids experiencing chronic tics by some estimates, and up to 20% of children experiencing transient tics. (Bloch & Lechman, 2009) Occasional, intermittent tic-like behaviors may be fairly common throughout the population. For reasons unknown, boys are around 3-times more likely than girls to develop tics.

The onset of tics

Tics typically emerge in childhood, with an average age of onset between 5 and 7. In rare cases they may emerge as late as 18. Motor tics typically appear first, years before vocal tics. Tic symptoms are generally at their most severe between the ages of 8 and 12, before steadily declining throughout adolescence in most children.

At any age a person can also experience the sudden onset of a tic disorder. This can occur in response to drug use, medication, illness, and various other medical conditions.

What causes tics?

The reason tics develop is still shrouded in a great deal of mystery. Some studies have suggested a genetic link, whereas others point more to environmental causes. We also know that tics can emerge rather suddenly, usually in response to something that inflames or damages the brain.

A number of studies have linked prenatal conditions to the development of tics. The use of nicotine, caffeine, or alcohol during pregnancy all increase the likelihood that a child will develop tics. Premature birth, low birth weight, and complications during delivery also raise the risk.

We know for a fact that drugs, chemicals, and medications can lead to the sudden onset of tic disorders. This suggests a neurobiochemical cause as opposed to something inherent in brain anatomy.

You should have your doctor do a blood test to rule out hypothyroidism, which can lead to the onset of tics. If your family has a history of liver disease, measuring serum copper and ceruloplasmin levels can determine if a child has Wilson’s Disease, another potential cause. In teenagers who have developed a sudden onset of tics, a urine drug screen should also be performed, since cocaine and other drug use can lead to the development of tics.

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, or PANDAS for short, is a fairly rare condition in which a child suddenly develops chronic tics after battling a strep throat infection. The belief is that in fighting to clear the body of the infection, the child’s immune system inadvertently attacks its own brain, leading to the onset of tics and/or other neurological disorders. It’s well known that inflammation and a overactive immune response can damage the body’s organs, including the brain.

A related offshoot of PANDAS is PANS: Pediatric acute-onset neuropsychiatric syndrome. The premise is pretty much the same, in that tics or other neurological problems suddenly emerge, usually after a child fights off some type of infection. Only instead of being caused by a strep throat infection in particular, PANS leaves the door open for any number of potential causes.

Tics & OCD
Tics are something separate and apart from obsessive compulsive disorder (OCD), although as many as 40% of people with OCD also have a tic disorder, and it’s often hard to tell the difference between the two, since they share many overlapping behaviors. (Conelea et al., 2014) There is also a disorder called ‘Tic-related OCD,’ which is like regular OCD only with more “counting, aggressive thoughts, symmetry and touching” compulsions.

The Effects & Consequences of Tics
Tics in and of themselves are not dangerous. They are not life-threatening, nor a sign of a degenerative disease (with the possible exception being PANDAS or PANS). The most severe complication is that it can lead to a child being teased, ostracized or bullied. If they make a person self-conscious, it can also lead to social withdrawal. Those who are punished, teased or misunderstood in childhood have far worse outcomes as adults.

Treatment for Tic Bites

Tic bites are typically treated with behavioral therapies such as exposure and response prevention (ERP), habit reversal training (HRT), or comprehensive behavioral intervention for tics (CBIT), which is a therapy designed specifically for tics based off the principles of HRT. Since tics are somewhat suppressible, these therapies train the patient to better recognize the signs that precede a tic, then help them develop a response that will interrupt this urge and prevent execution of the tic.

Since tics can also be related to stress or strong emotions, anything that reduces stress or helps a patient manage their emotions may also decrease the severity of a tic disorder.

Doctors should always rule out a physiological basis for tics. Medication usually isn’t necessary, and should be used as a last resort in the most extreme cases. When medication is used, doctors will generally prescribe typical and atypical neuroleptics; anti-seizure medications which can have both short- and long-term adverse consequences.

The good news about tics is that they generally decrease in severity as a child grows older. This is likely because growth in the cortex and other higher reasoning centers give the bran structures that inhibit such impulses more power, allowing a child to better control these impulses. Most kids see a significant decline in tics as they pass through adolescence (Dale, 2017), and fewer than 1 in 5 children with a tic disorder will continue to have symptoms in adulthood. (Pringsheim et al., 2019)