Aripiprazole as a Treatment for Fragile X Syndrome

Dr. Craig Erickson - Fragile X research

A decade ago, FRAXA funded a clinical trial of aripiprazole (also known as Abilify) for the treatment of irritability and aggression in individuals with Fragile X syndrome. Conducted by Dr. Craig Erickson and his team at the University of Indiana, the study tested aripiprazole on 11 males and 1 female with FXS for 12 weeks. Ten of these participants also had ASD. By the end of the 12 weeks:

  • All participants’ irritable behavior scored either “much improved” or “very much improved.”
  • Caregivers and parents reported at least a 25% improvement in irritability in their child’s behavior.
  • There were significant improvements in hyperactivity and social responsiveness.

Unfortunately, 2 participants left the trial early due to side effects, which were tiredness, drooling, and restlessness. However, there were no serious side effects.

Is Aripiprazole a Good Treatment for Fragile X?

The results of this trial are very positive. However, it is a small trial. A larger trial comparing aripiprazole to the effects of a placebo would be the next step in terms of clinical research. A larger trial would provide information on the long-term effects of aripiprazole on people with FXS, something that cannot be observed in a 12 week study. Unfortunately, the price tag would be in the millions of dollars, and the lack of funding for FXS research means that this is not possible right now.

The other caveat is that aripiprazole is an antipsychotic medication, a class of drugs which can cause side effects and risks, so careful discussion with a doctor is very important before considering it.

In the meantime, the results of this small trial are promising. Despite the lack of research into FXS specifically, aripiprazole is an effective antipsychotic that is already available as treatment for many mental health disorders. Doctors may prescribe it “off-label” for patients with FXS to treat irritability. Many people with FXS show irritability, which can sometimes lead to behaviors such as aggression, self-harm, and tantrums. Combined with behavioral therapies to help deal with new and unfamiliar situations mentally, aripiprazole can help an individual with FXS to live a safer and more peaceful life.

While a small study, our aripiprazole report still remains the only systematic, prospective study of newer generation antipsychotics in persons with Fragile X. This is surprising given that this drug class is the most commonly used drug class targeting interfering aggression and self-injury in this population. We would love to find a mechanism to further study aripiprazole in Fragile X with a large sample and use of placebo control. Regardless, our work laid a strong foundation for years of common prescribing of this drug in persons with Fragile X. We appreciate the work of FRAXA to make this work happen and in doing so essentially support my start in Fragile X research.

Craig A. Erickson, MD

Current Uses of Aripiprazole

Aripiprazole is currently used to treat:

  • Schizophrenia
  • Depression
  • Mania
  • Bipolar disorder
  • Autism
  • Tourette syndrome

Before this study, there had never been a clinical trial to test the usefulness and safety of any antipsychotic drug in patients with FXS, despite the fact that they are often prescribed. In fact, even in trials of autistic patients, people with FXS are routinely excluded due to the uniqueness of their condition.

That is why FRAXA funded the first systematic trial of aripiprazole in the treatment of FXS.

Read the Full Study

A prospective open-label study of aripiprazole in Fragile X syndrome.
Erickson CA1Stigler KAWink LKMullett JEKohn APosey DJMcDougle CJ.
Psychopharmacology (Berl). 2011 Jul;216(1):85-90.

¹Hatton DD, Hooper SR, Bailey DB, Skinner ML, Sullivan KM, Wheeler A (2002) Problem behavior in boys with Fragile X syndrome. Am J Med Genet 108(2):105–116

²Berry-Kravis E, Potanos K (2004) Psychopharmacology in Fragile X syndrome—present and future. Ment Retard Dev Disabil Res Rev 10(1):42–48


Global Leader in Fragile X Research

FRAXA-funded researchers around the world are leading the way towards effective treatments and ultimately a cure.

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Global Leader in Fragile X Research

FRAXA-funded researchers around the world are leading the way towards effective treatments and ultimately a cure.

Explore Current Research Grants
Help Fund the Cure