Should I add sertraline (SSRI) or fluoxetine (SSRI) to Abilify (aripiprazole) for a patient with autism, severe anxiety, and depression?

Adding an SSRI to Aripiprazole for Autism with Anxiety and Depression

Adding sertraline to aripiprazole is recommended for patients with autism who have severe anxiety and depression that is not adequately controlled with aripiprazole alone.

Rationale for Adding an SSRI

Patients with autism spectrum disorder (ASD) often experience comorbid anxiety and depression that can significantly impact their quality of life. When these symptoms are not adequately controlled with aripiprazole monotherapy, adding an SSRI is an evidence-based approach:

• The American Academy of Child and Adolescent Psychiatry (AACAP) suggests that combination treatment (medication plus therapy) is often more effective than monotherapy for anxiety disorders 1
• SSRIs are beneficial in reducing symptoms of depression and anxiety in patients with neurodevelopmental disorders 2
• Aripiprazole as monotherapy primarily targets irritability and behavioral symptoms in autism but may not adequately address anxiety and depression 3, 4

Choosing Between Sertraline and Fluoxetine

Sertraline advantages:

• Better tolerated at lower doses in patients with autism 5
• May have superior efficacy in severe depression compared to fluoxetine 6
• Shorter half-life allows for quicker dose adjustments if needed 1

Fluoxetine considerations:

• Longer half-life (requires less frequent dosing but takes longer to adjust) 1
• May require 3-4 weeks between dose adjustments compared to 1-2 weeks for sertraline 1

Recommended Implementation

1. Start with low-dose sertraline:

   • Begin with 25mg daily (lower than typical adult starting dose) 5
   • This "test dose" approach is particularly important as SSRIs can initially increase anxiety or agitation 1

2. Titration schedule:

   • Increase by 25mg increments every 1-2 weeks as tolerated 1, 5
   • Target dose range: 50-100mg daily for most patients with autism 5
   • Avoid exceeding 50mg daily initially, as higher doses (75mg+) have been associated with behavioral worsening in some patients with autism 5

3. Monitoring:

   • Assess for initial activation or increased agitation within the first week 1
   • Evaluate therapeutic response after 4-6 weeks at a stable dose 2
   • Use standardized measures to track anxiety and depression symptoms 2

Important Precautions

• Drug interactions: Monitor for potential interactions between sertraline and aripiprazole, as sertraline may interact with drugs metabolized by CYP2D6 1

• Discontinuation: If discontinuation is needed, taper gradually to avoid withdrawal symptoms, which can include anxiety, irritability, and sensory disturbances 7

• Side effect management: Common side effects include nausea, sleep changes, and increased sweating; these often improve with time 7

Special Considerations for Autism

• Patients with autism may respond to lower doses of SSRIs than typical patients 8, 5

• The beneficial effects of sertraline in autism may specifically target transition-associated anxiety and the "need for sameness" 5

• Some patients with autism may experience diminished response after several months of treatment, requiring dose adjustment or medication reassessment 5

• Parental oversight of medication regimens is crucial for ensuring proper adherence 1

By adding sertraline to aripiprazole, you can provide more comprehensive treatment addressing both the behavioral symptoms (targeted by aripiprazole) and the anxiety/depression symptoms (targeted by sertraline) in your patient with autism.