Autism and Tics: When Repetitive Behaviours Are More Than Stimming

Repetitive behaviours are a core feature of autism. Tics are a separate neurological phenomenon. When both are present in the same person, distinguishing one from the other matters for treatment. Getting it wrong means part of the clinical picture goes unaddressed.

In clinical practice, I see this regularly. An autistic child or adult comes in with repetitive movements, and everyone around them has assumed it is stimming. Sometimes it is. But sometimes what looks like stimming is actually a tic, or a mixture of both. That distinction matters, because the support you need for a tic is quite different from the support you need for a stim.

Tic disorders are more common in autistic people than in the general population. In some clinical samples, around 18% to 22% of autistic individuals also have a tic disorder. That is common enough to warrant paying attention to, not something to leave to chance. If you are considering an autism assessment or already have a diagnosis, understanding the overlap between autism and tics is important.

How Common Are Tics in Autistic People?

The overlap between autism and tics has been found consistently across multiple studies. In a clinical sample of autistic children and adolescents, Eapen and Gorman (2007) found tic disorders in 22%, split roughly evenly between Tourette’s syndrome and chronic motor tics. A more recent study by Kim, Song, and colleagues (2023) found tic symptoms in 18.4% of their autistic group.

To be clear, these are clinical sample figures rather than population-wide prevalence rates. But the message is consistent across studies: tics are common enough in autism that clinicians should be looking for them, and parents and autistic adults should know they exist.

Does It Work the Other Way Around?

Yes. Among people with Tourette’s syndrome, autism is also over-represented, though the exact rate depends on how autism is measured. Review-level estimates suggest ASD and Tourette’s co-occur in around 4% to 5% of cases, while broader tic disorder and autism overlap may sit around 9% to 12%. These conditions cluster together more often than chance would predict.

Is It a Tic or a Stim?

This is the question that matters most, and it is also the one with the least straightforward answer. There is no blood test, no scan, and no single checklist that reliably separates a tic from a stim in an autistic person. The distinction is usually made through careful history-taking and observation, looking at how the behaviour started, how it has changed over time, whether it can be suppressed, and what it feels like from the inside.

A helpful way to think about it: stimming is usually about regulation, while tics are usually about release. That is a simplification, not a diagnostic rule, but it captures the core difference well enough to be useful.

The Premonitory Urge

One of the most helpful clues is something called the premonitory urge. Most people with tics describe an uncomfortable internal sensation before the tic happens. A pressure, a tightness, a feeling that something is “not quite right” that builds until the tic occurs and then eases. If someone can identify that build-up-and-release pattern, it points strongly towards a tic rather than a stim.

A Complication Specific to Autism

Here is where it gets more difficult. Some autistic people have reduced interoceptive awareness, which means they may find it harder to notice and describe what is happening inside their own body. Research on tic experiences in autistic adults suggests that tics may be less consciously noticed in this group. So if someone cannot clearly describe a premonitory urge, that does not rule tics out. It may simply mean they find it hard to put the internal sensation into words.

When the Boundary Blurs

Some repetitive behaviours sit in a genuine grey area. A movement might look like a stim from the outside but have a tic-like quality from the inside, or the person themselves may not be sure which it is. Both can be present at the same time. An autistic person can stim and have tics, and the two can coexist in ways that make clean classification difficult.

This is one of the reasons why a thorough clinical assessment matters. Appearance alone is not enough to classify these behaviours with confidence. For a broader look at how stimming relates to autism, we have written a separate piece on that topic.

Why Do Tics Get Missed in Autistic People?

Because repetitive movements are already part of the diagnostic criteria for autism, there is a genuine risk that a co-occurring tic disorder gets attributed to autism and never identified in its own right. Eapen and colleagues made this point explicitly: tics in autistic people should not be overlooked and should be carefully evaluated.

Diagnostic Overshadowing

This is what clinicians call diagnostic overshadowing. When one diagnosis takes up all the attention, other things can hide behind it. A child who blinks repeatedly might have that behaviour noted down as an autistic stereotypy when it is actually a motor tic with a completely different mechanism. An adult who clears their throat constantly might never bring it up because they have always assumed it is just part of who they are.

The practical consequence is that the tic goes unrecognised and untreated. Tics have their own evidence-based treatments, quite separate from autism support, and missing them means the person is not getting help that could make a real difference to their daily life.

Gender and Under-Recognition

Both autism and tic disorders are more commonly identified in boys during childhood. In girls and women, both conditions are more likely to be camouflaged, misattributed, or interpreted through another diagnostic lens entirely. This means the overlap between autism and tics may be particularly under-recognised in females.

What Connects Autism and Tics Neurologically?

Both conditions involve brain systems that help filter sensations, habits, and actions. The basal ganglia and fronto-striatal circuitry are implicated in both autism and tic disorders, and both conditions feature differences in how repetitive behaviours are generated and regulated.

How This Differs from the ADHD and Tics Connection

In our companion piece on ADHD and tics, we explained how the overlap centres on action control and impulse regulation. The autism and tics overlap places more emphasis on sensory processing. Both conditions involve unusual sensory experiences, and some evidence suggests that sensory sensitivity may interact with how tics are felt and reported. Stress, fatigue, and sensory overload can all worsen tic expression in some autistic individuals.

Functional Tic-Like Behaviours: A Newer Piece of the Puzzle

Since the pandemic, clinicians have seen a significant increase in functional tic-like behaviours, particularly in adolescents and young adults. These are movements or sounds that resemble tics but have a different underlying mechanism. They tend to have a more abrupt onset, more complex movements, and a presentation that differs from the typical developmental course of Tourette’s syndrome.

Why This Matters for Autistic People

An international registry study by Martino and colleagues (2023) found autism spectrum disorder in 24% of people presenting with functional tic-like behaviours. That is a striking figure. It suggests autistic individuals may be particularly susceptible to developing these presentations, possibly because of existing differences in sensory processing, body awareness, or the way repetitive behaviours are expressed.

Distinguishing functional tic-like behaviours from primary tic disorders matters because the treatment approach differs. This is specialist-level assessment work, and getting it right requires a clinician experienced in both autism and movement disorders.

When Autism, ADHD, and Tics Are All Present

In clinical practice, it is not unusual to see all three conditions in the same person. Autism, ADHD, and tic disorders cluster together more often than chance would predict. The research has not yet produced a single clean prevalence figure for this three-way overlap, but the clinical reality is clear enough: when one neurodevelopmental condition is present, the others should be screened for.

We have covered the ADHD and tics relationship in detail in a separate blog. The relationship between Tourette’s and OCD is covered there as well.

What Helps When an Autistic Person Has Tics?

The first-line behavioural treatment for tics is CBIT, Comprehensive Behavioural Intervention for Tics. It teaches the person to notice the urge that comes before a tic and to use a competing response until the urge passes. For example, if the tic is shoulder shrugging, you gently tense and hold your shoulders down. If it is throat clearing, you practise slow, nasal breathing. This helps retrain the brain and reduce tic frequency over time.

Adapting CBIT for Autistic People

CBIT is still appropriate for autistic individuals, but how it is delivered may need to be adapted. The awareness component relies on noticing internal bodily sensations, and some autistic people find this harder because of differences in interoception. Practical adaptations might include using more concrete language, adding visual supports, working at a slower pace, spending more time building body awareness, and involving family members where that is helpful.

To be clear, we do not yet have large randomised trials comparing adapted versus standard CBIT specifically in autistic populations. The evidence base is still catching up. But the clinical logic for these adaptations is sound, and CBIT remains the best-supported behavioural approach we have for tics.

What Does Not Help

Telling someone to stop ticcing does not work. It increases stress and self-consciousness, and it almost always makes tics worse rather than better. This is something I want parents and teachers to really hear. Tic disorders are neurological. They are not voluntary, not attention-seeking, and not something a person can simply will away. What people need is understanding, proper assessment, and the right kind of support.

When Medication Is Considered

If tics are significantly impairing daily life, medication can help. Guidelines support alpha-2 agonists like clonidine or guanfacine, particularly when ADHD is also present. In more severe cases, a psychiatrist may consider other medications, carefully balancing benefits and side effects. This is specialist-level decision-making and should involve someone experienced in managing tic disorders alongside autism.

What Does the Research Say?

The evidence base for autism and tics is meaningful but thinner than the ADHD and tics literature, particularly for adults and treatment adaptation. Here are the key findings.

Co-occurrence

Eapen and Gorman (2007) found tic disorders in 22% of a clinical autism sample, including 11% with Tourette’s syndrome and 11% with chronic motor tics. Kim, Song, and colleagues (2023) found tic symptoms in 18.4% of their autistic sample. Review-level estimates place ASD and Tourette’s co-occurrence at around 4% to 5%, with broader tic disorder overlap ranging from 9% to 12%.

Tic Awareness in Autism

Research on tic phenomenology in autistic adults suggests that tics may look similar to Tourette’s-like phenomena but be less consciously noticed or less easily described. This has direct clinical implications: autistic adults may not volunteer tic symptoms unless specifically asked.

Functional Tic-Like Behaviours

The international registry study by Martino and colleagues (2023) found autism spectrum disorder in 24% of cases presenting with functional tic-like behaviours. This literature is recent and evolving, particularly since the post-pandemic increase in these presentations, but the autism over-representation is consistent across studies.

Treatment Evidence

CBIT and habit reversal training are well supported for tic disorders generally. Autism-specific comparative trials are sparse, but current reviews support the use of behavioural therapy for tic disorders in the presence of co-occurring conditions, with appropriate adaptation.

Getting the Right Assessment

If you are autistic and experiencing tics, or if you are a parent noticing repetitive behaviours in your child that do not quite fit the pattern of stimming, a comprehensive assessment can clarify the picture. The Private Therapy Clinic offers autism assessments and support for tics and Tourette’s syndrome, as well as ADHD assessments when the broader neurodevelopmental picture needs investigating. You can book a free 15-minute consultation to discuss what might