Duration of ADHD Medication Trial
You should trial ADHD medication for 4 weeks at adequate doses before deciding it's not working, with systematic dose titration occurring weekly during this period. 1
Systematic Titration Timeline
The American Academy of Child and Adolescent Psychiatry provides a clear 4-week titration protocol for determining medication effectiveness 1:
- Week 1: Start with low dose (5 mg methylphenidate or 2.5 mg amphetamine twice daily) and collect baseline ratings from multiple sources 1
- Week 2: Increase to 10 mg methylphenidate or 5 mg amphetamine if no improvement, obtain ratings 1
- Week 3: Increase to 15 mg methylphenidate or 7.5 mg amphetamine if needed (omit for children under 20 kg) 1
- Week 4: Increase to 20 mg methylphenidate or 10 mg amphetamine, then review all dose levels to select optimal dose 1
The key principle is that you must trial adequate doses before declaring failure—underdosing is a major problem in community practice that leads to falsely concluding medications don't work. 2
What Constitutes an Adequate Trial
An adequate trial requires three critical elements:
- Sufficient dose range: Over 70% of children respond to methylphenidate when a full range of doses is systematically trialed, and more than 90% respond to at least one stimulant class when both methylphenidate and amphetamines are tried 2
- Systematic assessment: Use standardized rating scales from teachers, parents, and patients (if age-appropriate) at each dose level to objectively measure response 1
- Clear target symptoms: The goal is maximum symptom reduction approaching levels of children without ADHD, not just "some improvement" 2
When to Switch Medications
If the first stimulant fails after adequate titration (4 weeks with proper dose escalation), switch to the alternative stimulant class rather than abandoning stimulants entirely 3, 2:
- If methylphenidate fails, trial amphetamines next 3
- If amphetamines fail, trial methylphenidate next 3
- Only after both stimulant classes have been adequately trialed should you consider non-stimulants like atomoxetine, extended-release guanfacine, or extended-release clonidine 3, 2
Common Pitfalls That Lead to Premature Discontinuation
The most critical error is stopping too early with inadequate doses. The MTA study demonstrated that community-treated children received lower medication doses and less frequent monitoring than those receiving optimal medication management, resulting in inferior outcomes 2. This creates a false impression that "medications don't work" when in reality they were never properly trialed.
Additional pitfalls include:
- Failing to use objective rating scales: Relying solely on subjective impressions rather than standardized measures from multiple informants 1
- Not accounting for different response patterns: Some target symptoms may require different doses, so prioritize which symptoms matter most 1
- Inadequate monitoring frequency: Weekly assessment during titration is essential, not monthly 1
Long-Term Considerations
Research shows that medication efficacy remains stable over time—treatment duration does not moderate effectiveness 4. However, medication-free periods should be implemented at regular intervals (such as annually) to reassess whether ongoing treatment remains necessary 5. The decision to continue long-term should be based on persistent functional impairment, not automatic continuation 5.
Special Population Considerations
For preschool children (ages 4-5), methylphenidate requires lower starting doses and smaller incremental increases due to slower metabolism, but the same 4-week systematic titration principle applies 2, 6.
For adolescents, screen for substance abuse before initiating treatment and monitor for medication diversion, but use the same 4-week titration timeline 2.
For adults, the same systematic approach applies with starting doses of 5 mg methylphenidate or 2.5-5 mg amphetamine, titrating weekly until symptom control is achieved 1, 7.