Tourette Syndrome (TS) is a neurodevelopmental disorder characterized by the presence of multiple motor tics and at least one vocal tic, which are sudden, brief, and repetitive movements or sounds. Tics are typically preceded by a premonitory urge, a sensation of tension or discomfort that is relieved by the execution of the movement or sound. Although TS is categorized as neurodevelopmental, it is widely perceived as a condition that appears exclusively during childhood. This prompts the question of whether a person can develop Tourette Syndrome for the first time later in life.
Defining the Standard Age of Onset
The formal diagnosis of Tourette Syndrome is linked to the age at which symptoms first appear. According to the criteria established by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), the onset of tics must occur before the individual turns 18 years old. Tourette Syndrome is fundamentally defined as a childhood-onset condition.
The typical age range for the first appearance of tics is between 4 and 6 years old, with the vast majority of cases beginning before the age of 10. This early onset reflects the condition’s neurodevelopmental nature, suggesting a genetic influence and developmental factors. The age limit of 18 serves to distinguish primary Tourette Syndrome from tic-like movements that begin in adulthood due to other causes.
Tics must also persist for more than one year since the first onset, though they can wax and wane in frequency and severity over that time. If a person experiences tics for the first time after their 18th birthday, the diagnosis of primary Tourette Syndrome cannot be made. This strict diagnostic boundary ensures that adult-onset tic disorders are investigated for potential underlying medical conditions.
How Tourette Syndrome Evolves in Adulthood
For individuals diagnosed with TS in childhood, the course of the disorder often changes as they mature. Tics commonly reach peak severity during early adolescence, between the ages of 10 and 12 years. Following this peak, the severity of tics tends to gradually diminish throughout the teenage years and into early adulthood.
While a substantial decrease in tic frequency and intensity is common, complete remission is less frequent than often assumed. Studies suggest that only about 10% to 20% of adults with a childhood TS diagnosis experience complete tic remission. Even when tics persist, they are often milder and more manageable than they were in childhood.
Tics are known to wax and wane, meaning they can increase in frequency and intensity during periods of heightened stress, anxiety, or fatigue. Conversely, concentrating on an absorbing task or being in a relaxed state can lead to a temporary reduction in tic activity. The long-term prognosis for most people with childhood-onset TS is generally positive.
Adult-Onset Tics: Secondary Causes
When tic-like movements appear for the first time after age 18, they are almost always classified as a Secondary Tic Disorder or another type of movement disorder. The sudden onset of tics in adulthood necessitates a thorough medical evaluation to rule out underlying causes, as it is clinically distinct from the neurodevelopmental process of primary TS. Adult-onset tics are often symptomatic of a medical condition, a substance effect, or a functional disorder.
Medication and Substance-Induced Tics
One category of adult-onset tics is those induced by medication or substance use. Certain prescription drugs, such as stimulants used for attention-deficit/hyperactivity disorder (ADHD) or neuroleptic medications used in psychiatry, have been reported to induce or exacerbate tics. Exposure to illicit substances, such as cocaine, can also trigger the onset of tic-like movements.
Neurological Injury or Disease
Tics beginning in adulthood can also be a symptom of an underlying neurological injury or disease. Conditions that affect the central nervous system can manifest with new-onset tics. In these cases, the tics are a symptom of acquired brain pathology, a condition sometimes referred to as “tourettism.”
Examples of such conditions include:
- Stroke
- Brain tumors
- Encephalitis (brain inflammation)
- Neurodegenerative diseases like Huntington’s disease
Functional Neurological Disorder (FND)
A growing number of adult-onset tic presentations are recognized as Functional Neurological Disorder (FND), also known as Psychogenic Non-Epileptic Tics. Functional tics are not consciously feigned but relate to a problem in the nervous system’s function, often triggered by psychological stress or a physical event. These functional tics can sometimes be differentiated from primary TS tics by their clinical characteristics.
These characteristics include:
- Acute, explosive onset
- Unusual complexity
- High suggestibility
- Lack of the distinct premonitory urge common in childhood-onset TS
A diagnosis of new-onset tics in adulthood requires careful differentiation of these secondary and functional causes from true, primary Tourette Syndrome.