Can Aripiprazole Cause Poor Appetite?
Aripiprazole is associated with decreased appetite in a subset of patients, though this is not its predominant metabolic effect—the FDA label reports decreased appetite in 5% of pediatric patients versus 4% on placebo, and the drug is generally considered weight-neutral or associated with modest weight loss rather than the weight gain seen with other antipsychotics. 1
Evidence from FDA Labeling and Clinical Trials
The FDA-approved prescribing information for aripiprazole documents decreased appetite as an adverse reaction occurring in pediatric patients (6-18 years), with an incidence of 5% compared to 4% in placebo-treated patients 1. This represents a minimal difference but confirms that appetite suppression can occur. Notably, the same data show that increased appetite occurred more frequently (7% versus 3% placebo), indicating that aripiprazole's effects on appetite are bidirectional and patient-specific 1.
In adult populations with schizophrenia, the FDA label does not list decreased appetite as a commonly observed adverse reaction (defined as ≥2% incidence and twice that of placebo), suggesting this effect is less prominent in adults 1.
Clinical Context: Aripiprazole's Unique Metabolic Profile
Aripiprazole stands apart from other second-generation antipsychotics due to its dopamine partial agonist activity, which contributes to a more favorable metabolic profile compared to agents like olanzapine and risperidone. 2
The Journal of the American Academy of Child and Adolescent Psychiatry guidelines document that in randomized controlled trials of 218 children (6-17 years) with autism spectrum disorder, aripiprazole's significant side effects included somnolence, weight gain, drooling, tremor, fatigue, and vomiting—but notably, appetite changes were not highlighted as a primary concern 2. This contrasts sharply with risperidone, where weight gain and increased appetite were consistently reported as significant adverse effects 2.
Real-World Clinical Experience
In a naturalistic study of 142 hospitalized psychiatric patients treated with aripiprazole, adverse effects were infrequent (15.5%), with the most common being behavioral activation or nausea rather than appetite changes 3. The study noted that many patients were obese at admission, and aripiprazole was generally well-tolerated without significant metabolic concerns 3.
A particularly compelling case report documented dramatic weight loss (37 pounds over 4 months) when aripiprazole was added to olanzapine in a patient with treatment-resistant schizophrenia, despite no changes in dietary intake or physical activity. 4 This suggests that aripiprazole may actively counteract the appetite-stimulating and weight-gaining effects of other antipsychotics through its unique pharmacological mechanism 4.
Comparative Metabolic Effects in Pediatric Populations
A 2-year observational study of 127 pediatric outpatients compared weight trajectories between risperidone (81% of patients) and aripiprazole (19%) 5. While risperidone showed trends toward BMI-Z increase in children and decrease in adolescents, aripiprazole was associated with significant BMI-Z increase, particularly in children 5. However, this weight gain with aripiprazole was still considerably less than that typically seen with risperidone or olanzapine 5.
Clinical Implications and Monitoring
When aripiprazole causes decreased appetite, this effect is typically mild and occurs in a minority of patients. The clinical significance depends on the patient's baseline nutritional status:
- In patients who are overweight or obese, mild appetite suppression may be clinically neutral or even beneficial 3
- In underweight patients or those with pre-existing nutritional concerns, monitor weight weekly for the first month, then monthly thereafter 6
- In pediatric patients, the 5% incidence of decreased appetite should be weighed against the 7% incidence of increased appetite when counseling families 1
Critical Pitfalls to Avoid
Do not assume that appetite suppression with aripiprazole will be clinically significant or persistent. The FDA data show minimal difference from placebo in most patients 1. Unlike SSRIs such as fluoxetine (which causes anorexia in 11% of patients) or appetite stimulants like mirtazapine (which increases appetite in approximately 80% of patients), aripiprazole's effects on appetite are generally modest and variable 7, 6.
Do not discontinue aripiprazole solely due to mild appetite changes without considering the underlying psychiatric indication. The drug demonstrates efficacy for irritability, hyperactivity, and stereotypy in autism spectrum disorder, with 56% positive response rates at 5 mg daily versus 35% on placebo 2. The benefits for the primary psychiatric condition typically outweigh mild appetite effects.
When Appetite Stimulation is Specifically Needed
If a patient requires both antipsychotic treatment and appetite stimulation, aripiprazole is not the optimal choice. Consider alternative strategies:
- Switch to an antipsychotic with appetite-stimulating properties (though this comes with higher metabolic risks) 2
- Add mirtazapine 15 mg nightly if depression coexists, as this provides robust appetite stimulation through histamine H1 receptor blockade 6
- Avoid systematic use of appetite stimulants like dronabinol or megestrol acetate, as evidence is limited with potentially harmful side effects 7