Treatment of ADHD in Patients with Comorbid Bipolar Disorder

Critical Sequencing: Mood Stabilization Must Precede ADHD Treatment

The American Academy of Child and Adolescent Psychiatry recommends stabilizing bipolar symptoms first with a mood stabilizer before initiating any ADHD medication, as treating ADHD in the context of unstable mood symptoms can worsen bipolar disorder 1, 2
The mood stabilizer regimen needed to achieve acute stabilization should be maintained for 12-24 months minimum, as relapse rates exceed 90% in non-compliant patients 1, 2
Document adequate mood stability for at least 4-8 weeks before adding ADHD pharmacotherapy 1

The standard starting dose of atomoxetine is 40 mg once daily, which can be increased by 20 mg increments every 7-14 days based on tolerability and response, with a maximum dose of 100 mg/day or 1.4 mg/kg/day (whichever is less) 3
The target dose is typically 80-100 mg daily for optimal efficacy, and 4-6 weeks at target dose are required to assess full therapeutic effect 3

Patients with bipolar disorder require more intensive monitoring when adding atomoxetine, with systematic assessment for both ADHD symptom improvement and mood destabilization 1
Monitor weekly during initial titration for mood symptoms that could signal emerging mania, and screen systematically for suicidal ideation at each visit 1
Assess cardiovascular parameters at each adjustment, as atomoxetine causes modest increases that are generally well tolerated 4

Never initiate atomoxetine during an acute mood episode, as ADHD treatment should only begin after mood stabilization 1, 2
Do not discontinue the mood stabilizer when adding atomoxetine, as combination therapy is required and monotherapy switches led to relapse in >50% of patients within 3 months 1, 2

If atomoxetine proves ineffective, low-dose stimulants can be cautiously added to the mood stabilizer regimen, as demonstrated safe and effective in one randomized controlled trial of 40 bipolar youth stabilized on divalproex 1, 2
Use lower stimulant doses than typical for ADHD-only patients, and monitor even more closely for mood destabilization 1