How should I manage aggression in my 7‑year‑old son with ADHD and emotional disorder who is taking lisdexamfetamine (Vyvanse) 20 mg daily?

Management of Aggression in a 7-Year-Old on Vyvanse 20 mg

First, implement parent training in behavioral management immediately while simultaneously reassessing whether the aggression represents stimulant-induced irritability versus unmasking of comorbid oppositional defiant disorder, conduct disorder, or mood dysregulation. 1, 2

Immediate Assessment Steps

Determine if Vyvanse is causing or worsening the aggression:

• Stimulants paradoxically reduce aggressive behaviors in most children with ADHD when the aggression stems from impulsivity and poor self-regulation 1, 2
• However, if aggression emerged or worsened after starting Vyvanse, consider stimulant-induced irritability as a medication side effect 1
• Evaluate timing: Does aggression occur during peak medication effect (midday) or during wear-off (late afternoon/evening)? 2
• Look for comorbid symptoms: explosive temper, mood lability, defiance beyond typical ADHD impulsivity, or premeditated aggressive acts 1, 2

Treatment Algorithm

Step 1: Optimize Behavioral Interventions (Start Immediately)

Parent management training is non-negotiable and must occur alongside any medication changes: 1, 2, 3

• Teach specific techniques: trigger identification, distraction skills, calming strategies, self-directed time-out, and assertive expression of concerns 2
• Address oppositional behaviors, aggression, and noncompliance that extend beyond core ADHD symptoms 1, 2
• Behavioral interventions have extensive randomized controlled trial support for anger, irritability, and aggression 2

Step 2: Medication Decision Tree

If aggression is NEW or WORSE since starting Vyvanse:

• Consider that lisdexamfetamine may be causing irritability as a side effect 1
• Trial a medication holiday (weekend off) to assess if aggression improves off medication 2
• If aggression clearly improves off medication, switch to methylphenidate formulation, as some children tolerate one stimulant class better than another 4, 1

If aggression predated Vyvanse or persists despite adequate ADHD symptom control:

• Ensure Vyvanse dose is optimized (can increase to 30-40 mg if ADHD symptoms remain undertreated, as better ADHD control often reduces impulsive aggression) 1, 2
• Lisdexamfetamine can be titrated by 10 mg weekly up to 70 mg maximum, though 20-40 mg is typical for a 7-year-old 4
• If aggression persists despite 4-6 weeks at optimized stimulant dose with behavioral therapy, proceed to Step 3 2, 3

Step 3: Add Adjunctive Medication for Persistent Aggression

The American Academy of Child and Adolescent Psychiatry recommends divalproex sodium as the preferred next medication for explosive temper and severe aggressive outbursts: 1, 2, 3

• Dosing: 20-30 mg/kg/day divided BID-TID, titrated to therapeutic blood levels of 40-90 mcg/mL 2, 3
• Demonstrates 70% reduction in aggression scores after 6 weeks at therapeutic levels 1, 2
• Particularly effective for explosive temper and mood lability 1, 2
• Monitor liver enzymes regularly 2

If divalproex is ineffective after 6-8 weeks at therapeutic levels or poorly tolerated, consider risperidone: 1, 2, 3

• Risperidone has the strongest controlled trial evidence for reducing aggression when added to stimulants in children with intellectual disability and disruptive behaviors 4, 1
• Target dose: 0.5-2 mg/day (mean effective dose 1.16-2.9 mg/day in trials) 4, 1
• Significant improvements in aggression, irritability, and conduct problems typically begin within 2 weeks 4
• Critical monitoring required: weight gain (mean 2.84 kg over 6 weeks), metabolic syndrome, movement disorders, asymptomatic prolactin elevation 4, 1
• Common side effects: somnolence (51%), headache (29%), increased appetite 4

Common Pitfalls to Avoid

• Do not assume the stimulant is causing aggression without a trial off medication – stimulants actually reduce aggression in most ADHD children 1, 2
• Do not skip behavioral interventions – medication alone is insufficient for aggression management 1, 2, 3
• Do not rush to antipsychotics – try optimizing stimulant dose and adding behavioral therapy first, then divalproex before risperidone due to metabolic risks 1, 2, 3
• Do not use benzodiazepines like alprazolam – not indicated for ADHD with aggression due to dependence risk 1
• Do not combine multiple mood stabilizers without clear rationale – increases adverse effects without proven benefit 3
• Trial each medication for 6-8 weeks at therapeutic doses before declaring failure – avoid polypharmacy pitfalls 2, 3

When to Consider Higher Level of Care

If aggression remains severe despite optimized treatment (stimulant + behavioral therapy + mood stabilizer or antipsychotic), consider intensive in-home therapies, partial hospitalization, or inpatient admission for safety 3