The most common side effect of Abilify (aripiprazole) is akathisia, an inner restlessness and compelling urge to move. In clinical trials, akathisia affected roughly 5% to 15% of patients depending on the dose and condition being treated, making it consistently more frequent than any other side effect. Other common effects include nausea, insomnia, tremor, and sedation, but akathisia is the one that sets Abilify apart from many other medications in its class.
What Akathisia Feels Like
Akathisia is not ordinary restlessness. People describe it as an uncomfortable inner drive to keep moving, a sensation that sitting still feels almost intolerable. You might find yourself pacing, shifting your weight from foot to foot, crossing and uncrossing your legs, or feeling an agitation that’s hard to put into words. It’s a physical sensation, not just anxiety, though the two can be difficult to tell apart.
This distinction matters because akathisia is sometimes mistaken for worsening anxiety or the psychiatric condition being treated. If you start Abilify and notice a new, physical sense of restlessness that wasn’t there before, that’s worth raising with whoever prescribed it. Akathisia typically shows up within the first days to weeks of starting the medication or increasing the dose.
Why Abilify Causes Restlessness
Abilify works differently from most other antipsychotic medications. Rather than fully blocking dopamine receptors in the brain, it acts as a partial activator. Think of it as a dimmer switch instead of an on/off switch: it dials dopamine signaling down when it’s too high and props it up slightly when it’s too low. This mechanism gives Abilify some advantages, including fewer movement-related side effects like stiffness and fewer hormonal disruptions compared to older antipsychotics. But that partial activation of dopamine receptors is also what makes akathisia more likely. Newer medications designed to be even gentler on dopamine receptors were specifically developed to reduce this restlessness, which confirms how closely tied it is to Abilify’s core mechanism.
Other Common Side Effects
Beyond akathisia, the side effects that appear most frequently in clinical data include:
- Nausea and digestive issues: Nausea, vomiting, constipation, and indigestion are all reported. These tend to be most noticeable in the first few weeks and often ease as your body adjusts.
- Insomnia: Difficulty falling or staying asleep is common, likely because of the same dopamine activity that causes restlessness.
- Sedation or dizziness: Some people experience the opposite pattern, feeling drowsy or lightheaded, particularly early in treatment.
- Tremor: A mild shaking, usually in the hands, can occur, though it’s less frequent than with older antipsychotics.
Many of these effects improve over time without any change in treatment. The body often adapts within the first several weeks, and side effects that seemed significant at the start may fade or become manageable.
Weight Gain on Abilify
Abilify has a reputation as one of the more “weight-neutral” antipsychotics, but that label can be misleading. In a study of people with early psychosis, those taking aripiprazole gained an average of 7.1 kilograms (about 15.6 pounds) over a median treatment period of 15 months, while people not taking any antipsychotic did not gain weight. The oral form was associated with more weight gain (around 11 kg) than the long-acting injectable form (around 3.7 kg) over the same period.
So while Abilify generally causes less weight gain than some other antipsychotics, it’s not zero. If you’re watching for this, tracking your weight in the first few months gives you useful information to discuss with your prescriber.
Effects on Blood Sugar and Cholesterol
Abilify’s metabolic profile is relatively favorable compared to other antipsychotics. A one-year study of patients who switched to aripiprazole found that blood sugar levels normalized in all participants over the study period. LDL cholesterol (the “bad” kind) dropped in about two-thirds of patients and normalized in a third of them. HDL cholesterol (the “good” kind) improved in roughly a third of patients. Triglyceride levels were more mixed, rising in about two-thirds of patients. These numbers suggest Abilify is less likely to cause the severe metabolic problems associated with some other antipsychotics, though regular blood work is still a reasonable precaution.
Compulsive Behavior Warnings
One of the more unusual risks associated with Abilify is the development of intense, hard-to-control urges. The FDA’s prescribing information includes a specific warning about pathological gambling, compulsive shopping, binge eating, and compulsive sexual behavior. These urges can appear in people with no prior history of such behaviors.
What makes this side effect particularly tricky is that you may not recognize it as medication-related. The urges can feel like personal choices rather than a drug effect. In reported cases, some people experienced significant financial or personal harm before the connection was identified. In many (though not all) cases, the urges stopped when the dose was lowered or the medication was discontinued. If you or someone close to you notices new compulsive patterns after starting Abilify, that’s important information for your prescriber.
Side Effects in Children and Teens
Children and adolescents taking Abilify experience the same general side effect profile as adults, with some important differences. Weight gain may be more pronounced in younger patients than in adults. Aripiprazole is also among the antipsychotics with a higher risk of neurological side effects in children, including movement-related symptoms. Because young people are still developing metabolically, weight changes and metabolic shifts carry more long-term significance than they might in a middle-aged adult starting the same medication.