Percentage of Children Developing Tics from ADHD Stimulant Medications
The risk of developing new tics or worsening of existing tics with stimulant medications is approximately 5.7% (95% CI = 3.7%-8.6%), which is similar to the placebo rate of 6.5% (95% CI = 4.4%-9.5%), indicating that stimulants do not significantly increase the risk of tics in children with ADHD. 1
Evidence on Stimulants and Tic Development
Meta-analysis of 22 randomized controlled trials involving 2,385 children found no statistically significant difference in the risk of new onset or worsening tics between stimulant treatment and placebo (risk ratio = 0.99,95% CI = 0.78-1.27) 1
Older literature from the 1980s suggested that stimulants might increase tic severity in 25% to 50% of patients with Tourette's Syndrome, but this has not been supported by more recent controlled studies 2
The American Academy of Child and Adolescent Psychiatry notes that controlled studies have not found that methylphenidate worsens motor tics in Tourette's syndrome or increases motor tics in children with ADHD without pre-existing tic disorders 3
Medication-Specific Findings
In a retrospective chart review of 555 children treated with stimulants for ADHD, the overall rate of tic emergence was 7.8% 4
- 8.3% with methylphenidate
- 6.3% with dextroamphetamine
- 7.7% with pemoline 4
Data from the OROS methylphenidate (Concerta) clinical development program showed that the incidence of tics was not significantly different across treatment groups:
- OROS methylphenidate: 4.0%
- Immediate-release methylphenidate three times daily: 2.3%
- Placebo: 3.7% (p = 0.5249) 5
During the first year of a 2-year open-label study with OROS methylphenidate, the monthly incidence of tics remained constant at approximately 5%, with no correlation between dose and frequency of tic episodes 5
Risk Factors for Tic Development
Children who develop tics while on stimulant medication are significantly younger than those who do not 4
The risk of tic episodes is higher in patients with a history of tics than in those with no history (33% versus 7%, p < 0.0001) 5
Higher doses of stimulant medication are not associated with increased likelihood of developing tics 4
Clinical Implications
While stimulants were historically contraindicated in patients with tic disorders, this absolute contraindication is no longer supported by data from randomized controlled trials 3
The American Academy of Child and Adolescent Psychiatry suggests that the benefits of treating ADHD symptoms may outweigh the impact of mild tics, and therefore effective ADHD treatment should not be automatically discontinued if mild tics develop 3
Only a small percentage (4%) of children with a history of tics withdraw from therapy because of tic exacerbation 5
For children who do experience tics with stimulants, alternative medications such as atomoxetine have been shown not to worsen tics in clinical trials 3
Methylphenidate may be less likely to exacerbate tics than amphetamine-based medications like Adderall 3
Important Considerations for Clinicians
When tics emerge during stimulant treatment, clinicians should consider that these may have developed coincidentally rather than being caused by the medication 1
Meta-regression analysis shows that type of psychostimulant, dose, duration of treatment, and participant age do not affect risk of new onset or worsening of tics 1
Proper ADHD treatment can actually reduce stress that may trigger tics, and in some patients, tics may improve with better overall symptom control 3