What is a tic? Simply put, tics are sudden twitches of whole muscle groups, most often affecting the eyes, mouth, shoulders, or neck. A tic can manifest as movement — like rapid uncontrolled blinking of the eyes — or as sounds, like clearing the throat or making grunting noises.
Everyone experiences tics from time to time. A sudden spasm can cause a violent twitch that can surprise or embarrass the person who experienced it. In most cases, though, these one-off tics are harmless and temporary. When the tics become regular and prolonged, however, they may be caused by a tic disorder.
Tic disorders rarely travel alone. They’re most commonly seen with ADHD, obsessive-compulsive disorder, and major depressive disorder. They are more common among men than women, and they show up more often in children — some studies estimate that as many as 20 percent of kids have tic disorders. As children age, this percentage falls — by adulthood, only about 1 in 100 people has a tic disorder.
Types of Tics and Tic Disorders
Tic disorders fall into four categories, according to The American Psychiatric Association (APA)’s Diagnostic and Statistical Manual of Mental Disorders (DSM-V):
1. Transient tic disorders: Multiple tics, lasting more than 4 weeks but less than 12 months. This is the most common tic disorder diagnosis, and is thought to affect anywhere between 5 and 25 percent of school children at any given time. In some cases, patients experience multiple episodes of transient tic disorder, with tic-free periods in between.
2. Chronic tic disorder: Either a single tic or multiple motor and vocal tics (not both), which have been present for more than a year. For a diagnosis of chronic tic disorder, the symptoms must appear before age 18.
3. Tourette Syndrome: Multiple motor tics and multiple vocal tics that have been present for more than a year. Tourette’s is the most severe tic disorder, and is typically diagnosed between the ages of 5 and 18. Around 200,000 people in the United States live with Tourette Syndrome.
4. Tic Disorder NOS: Tics are present, but meet none of the categories listed above. This category mostly applies to adults, since most other tic disorders are diagnosed in childhood.
The tics themselves come in two forms: motor tics and vocal tics. From there, they’re further delineated into two categories: simple and complex.
Simple motor tics:
- Eye blink, eye roll
- Neck jerk, jaw thrust
- Nose twitching, face grimacing, head jerking
- Arm or leg thrusting, muscle tightening (commonly the buttocks or abdomen)
Complex motor tics:
- Series of movements performed in the same order
- Mimicking movements of others
- Vulgar movements
- Friendly gestures (waving, thumbs up, etc.)
- Frozen posture (“statue-like”)
Simple vocal tics:
Note: Simple vocal tics often occur in repeated bouts, and don’t seem to mimic real words or any form of spoken language.
Complex vocal tics:
- Mimicking words said by others
- Repeating phonemes
- Unintentional obscene words or statements
- Random words, blurted without intention to communicate
These tics aren’t classified as involuntary movements — rather, experts have deemed them “unvoluntary,” meaning that the person can suppress them with focus. However, the suppression is uncomfortable; this discomfort is usually relieved only by performing the tic.
Understanding Tic Disorders
Experts are still not sure what causes tics to occur. Some genetic element seems to exist, as tic disorders tend to run in families. Stress and lack of sleep seem to make tics worse, but there’s no evidence that they cause tics to develop.
For years, experts worried that stimulant medications used to treat ADHD caused tic disorders, but more recent research indicates this may not be the case. Instead, it seems that while stimulant medications do not cause tics, they may bring them out in individuals who are genetically predisposed to them. For this reason, doctors may be reluctant to start stimulant medication with patients reporting a family history of tics. In most instances, the tics go away once the medication is discontinued.
Since the majority of tics stop on their own without treatment, many experts recommend a “wait and see” approach for tic disorders in children, especially if they cause the individual minimal embarrassment. If the tics persist — or cause great distress to the individual — some medications can be used to help suppress them. Stress reduction techniques and behavioral therapy have also been shown to work wonders, for both children and adults with tic disorders.