Published by Unseen Progress, an independent publisher of caregiver research. Last reviewed 2026-05-10. Part of the tic disorders research overview.
Short answer. Most children with Tourette syndrome have at least one comorbid neurodevelopmental condition — typically ADHD (roughly 50–60%), OCD (roughly 30–40%), or both (Freeman et al., 2000; Hirschtritt et al., 2015). The comorbidities often produce more day-to-day impairment than the tics themselves. The current treatment consensus is to identify and treat the most impairing condition first, which is rarely the tics, and to use medications and behaviour therapies that work for the comorbid condition without making tics meaningfully worse (Pringsheim et al., 2019; Bloch et al., 2009).
The large international Tourette cohort (Freeman et al., 2000) and subsequent genetic and clinical studies (Hirschtritt et al., 2015) have shown that pure Tourette syndrome — tics without any comorbid condition — is the minority presentation. The typical profile is:
The genetic literature suggests these are not coincidental co-occurrences but reflect shared underlying neurodevelopmental pathways. The clinical implication is that families presenting with "Tourette" almost always need a treatment plan that addresses more than tics.
The functional-impact research (Conelea et al., 2011; Eapen et al., 2016) consistently shows that when both are present, ADHD and OCD usually contribute more to academic, social, and family impairment than tics do. The implications are practical:
This is why the practice guideline (Pringsheim et al., 2019) and most specialist clinics now lead with: assess all three (tics, ADHD, OCD), measure functional impact for each, and sequence treatment by impact rather than by which diagnosis came first.
The historical concern that stimulants cause or worsen tics has been substantially revised by the evidence. The current position (Bloch et al., 2009; Pringsheim et al., 2019; Cohen et al., 2015):
For families where stimulants are not tolerated or are declined, the practice guideline endorses guanfacine, clonidine, and atomoxetine as alternatives. Guanfacine and clonidine have the additional property of being mildly tic-suppressing, which makes them an appealing first choice when both conditions are present and moderate.
OCD with comorbid tics has two specific clinical features (Bloch & Leckman, 2009; Hirschtritt et al., 2015):
The treatment is the same as for OCD generally: exposure and response prevention (ERP), often with an SSRI as adjunct. SSRIs are not contraindicated in tic disorders and do not typically worsen tics. The behavioural work — ERP for OCD — is qualitatively different from CBIT (which targets the urge with a competing response), and a clinician trained in both is helpful when both conditions are present.
A child with all three conditions can end up with a treatment plan that includes:
This is a lot. The practical sequencing question — which to start first — has been studied (Pringsheim et al., 2019) and the consensus is:
1. Treat the most impairing condition first. 2. Avoid introducing more than one new treatment at a time, so any response or side effect can be attributed. 3. Allow 4–8 weeks before judging effect, except for stimulants where the effect window is shorter. 4. Re-measure functional impact at each step. Severity rankings often shift as the most impairing layer is reduced.
Habit reversal (CBIT) and exposure and response prevention (ERP) share a common structural feature — both teach the child to feel an internal trigger (urge in CBIT, anxiety in ERP) and let it pass without performing the usual response. A child who has done one often has a head start on the other.
That said, the targets are different. CBIT works on the premonitory urge with a physically incompatible competing response. ERP works on the obsessive anxiety with deliberate non-response. Conflating them, which sometimes happens in school counselling or with general therapists, leads to neither being applied correctly.
In early childhood, ADHD symptoms often dominate the picture before tics emerge. In middle childhood, tics intensify and ADHD remains. In adolescence, OCD often emerges or intensifies, while tics typically begin their decline. The peak of total impairment is therefore often the late primary / early middle-school years, when all three layers are most active simultaneously.
For a parent of a child with tics and a suspected or confirmed comorbidity:
1. Get all three (tics, ADHD, OCD) formally assessed. Comorbid conditions are common enough to actively check for. 2. Rank by functional impact, not diagnostic severity. The condition causing the most school and family impairment is usually not the most visible one. 3. Trust the stimulant evidence in group terms, but monitor individual response. Untreated ADHD has its own costs. 4. Introduce treatments one at a time, with 4–8 weeks between, so the source of any change is identifiable. 5. Find a clinician comfortable with both CBIT and ERP if both tic and OCD work are indicated. The two are different and need to be delivered as such.
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