Can Aripiprazole (Abilify) Be Added to Mirtazapine?
Yes, aripiprazole can be safely added to mirtazapine, and this combination is supported by both clinical evidence and guideline recommendations, particularly for treatment-resistant depression, negative symptoms in schizophrenia, and to mitigate metabolic side effects.
Clinical Context and Evidence Base
The combination of aripiprazole with mirtazapine has multiple evidence-based applications:
For Treatment-Resistant Depression
Aripiprazole augmentation is an established strategy when antidepressants alone prove insufficient. The most recent schizophrenia guidelines 1 explicitly recommend aripiprazole augmentation for persistent negative symptoms and depressive symptoms, noting that "antidepressant augmentation in the absence of a diagnosis of depression might still have a beneficial effect on negative symptoms" 1. While these guidelines focus on schizophrenia, the principle of aripiprazole augmentation extends to major depressive disorder.
Research directly supports this combination: A 2007 study 2 demonstrated that combined mirtazapine (45 mg/day) plus aripiprazole (15 mg/day) accelerated the onset of antidepressant action in treatment-resistant depression compared to mirtazapine monotherapy, with comparable overall efficacy but faster response times.
Optimal Dosing Strategy
Start with low-dose aripiprazole (2-5 mg/day) when augmenting mirtazapine. A 2022 dose-effect meta-analysis 3 found that aripiprazole doses between 2-5 mg achieved optimal efficacy (OR 1.46-1.93) with better tolerability than higher doses, with no additional benefit observed at doses above 5 mg up to the maximum 20 mg. The efficacy curve plateaus after 5 mg, making higher doses unnecessary and potentially less tolerable.
Metabolic and Side Effect Considerations
Weight Management Benefits
A significant advantage of adding aripiprazole to mirtazapine is mitigation of weight gain. Mirtazapine commonly causes increased appetite and weight gain 4. The 2007 study 2 specifically noted that "additive use of aripiprazole reduced the mirtazapine-induced increase in body mass index."
Recent obesity guidelines 5 recommend considering aripiprazole switching when weight gain occurs with other antipsychotics, as aripiprazole has a more favorable metabolic profile. This principle applies when augmenting mirtazapine—aripiprazole may actually counteract mirtazapine's metabolic effects.
Akathisia Management
Mirtazapine may actually help manage aripiprazole-induced akathisia. The 2007 study 2 found that "mirtazapine had favourable effects on aripiprazole-induced akathisia," and a 2014 study 6 demonstrated that low-dose mirtazapine (15 mg/day) significantly reduced akathisia severity in patients taking aripiprazole, with 62.5% of patients showing clinical response.
This creates a synergistic tolerability profile: aripiprazole reduces mirtazapine's weight gain, while mirtazapine reduces aripiprazole's akathisia risk.
Safety Profile
The combination is well-tolerated with no significant drug-drug interactions. The FDA label for aripiprazole 7 does not list mirtazapine as having clinically significant interactions. The 2007 study 2 reported that "combined therapy with mirtazapine and aripiprazole is a safe and well-tolerated treatment option" with no extrapyramidal side effects beyond manageable akathisia.
Monitoring Requirements
Before initiating aripiprazole, obtain baseline measurements 1:
- BMI and waist circumference
- Blood pressure
- Fasting glucose or HbA1c
- Lipid panel
- Prolactin level
- ECG (to assess QTc interval)
Recheck fasting glucose at 4 weeks, then monitor BMI, waist circumference, and blood pressure weekly for 6 weeks, followed by comprehensive metabolic monitoring at 3 months and annually thereafter 1.
Practical Implementation Algorithm
Confirm inadequate response to mirtazapine monotherapy after at least 4-8 weeks at therapeutic dose 8
Start aripiprazole at 2-5 mg/day (not the higher doses often used in schizophrenia) 3
Continue mirtazapine at current dose (typically 15-45 mg at bedtime) 4
Assess response at 2-4 weeks:
- If partial response: may increase aripiprazole to maximum 5 mg/day
- If no response: consider alternative strategies rather than exceeding 5 mg
- If good response: maintain combination
Monitor for akathisia in first 2 weeks—if occurs, mirtazapine's antihistaminic properties may help, but consider dose reduction of aripiprazole first 6
Track weight and metabolic parameters as outlined above
Common Pitfalls to Avoid
- Don't start with high-dose aripiprazole (10-20 mg)—this offers no additional benefit and worsens tolerability 3
- Don't discontinue mirtazapine abruptly if switching strategies—taper over 10-14 days to limit withdrawal symptoms 8
- Don't overlook cardiovascular monitoring—both drugs can affect QTc interval, though risk is low 9, 7
- Don't assume all antipsychotic augmentation is equivalent—aripiprazole's partial D2 agonism creates unique benefits when combined with mirtazapine 1
Special Populations
For patients with cardiovascular disease, mirtazapine is considered safe 9, and low-dose aripiprazole augmentation can be used with appropriate ECG monitoring. In elderly patients, start with even lower doses (aripiprazole 2 mg, mirtazapine 7.5 mg) and titrate more gradually 8, 7.