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It’s Easy to Love the Love Hormone; But I’m Not Ready to Say “I Do” …

December 09, 2013

 POV by developmental-behavioral pediatrician Paul Wang, Autism Speaks’ senior vice president for medical research.


Among treatments being studied for autism spectrum disorders (ASD), oxytocin seems to generate the most consistent excitement. The media love to talk about the “love hormone,” which is produced naturally by the human body and has an important role in social behavior. Compared to the antipsychotic drugs and other medicines often prescribed for individuals with ASD, oxytocin may feel like a “friendlier” alternative.

Is the excitement about oxytocin justified?  My answer is “yes and no.”  Yes, there’s plenty of reason to continue studying oxytocin, as it may well have benefits for some portion of the ASD population. And no, because so far the evidence that oxytocin has real-life benefits for people with ASD is limited and weak and because we know next to nothing about its long-term safety.

Let’s start with the positive. Research in animals and humans shows that oxytocin has a broad role in social behavior, from infant bonding and monogamy in animals to trust and emotion recognition in people. As a side note, some of the most important animal research on oxytocin was led by a young scientist named Thomas Insel, decades before he became the director of the National Institute of Mental Health. 

In recent years, Autism Speaks has funded a number of studies to advance understanding of oxytocin’s effects and illuminate the brain pathways through which it operates. This knowledge is critical for designing definitive clinical studies of oxytocin’s possible benefits.

So why not start prescribing oxytocin for treating autism today?

First, we need larger, longer studies to understand whether oxytocin is safe for long-term use. Just because oxytocin is a natural hormone doesn’t mean it’s safe to administer in an uncontrolled fashion. For example, we know that thyroid hormone, insulin and growth hormone have significant and dangerous side effects when taken inappropriately. Animal research suggests that long-term use of oxytocin can suppress the body’s own production of this hormone and that its use may worsen certain social behaviors.

We also lack studies of oxytocin’s real-life effects when taken for months or even years at a time. Almost all the studies conducted to date have been in a laboratory setting using experimental social tests. In fact, only a few involved taking oxytocin for more than a day. Moreover, many of the early studies didn’t use a comparison group taking a placebo, or dummy treatment. This makes it hard to know if the effects were really due to oxytocin versus expectations.

There have been three rigorous clinical trials of oxytocin. Two showed disappointing results. In one study, published in 2012, Canadian researchers administered four days of oxytocin treatment paired with social skills training to 19 adults with autism. These researchers did not find greater improvement on oxytocin than on placebo. This year, Australian researchers published the results of a larger, six-week study in adults with autism on the less-disabled end of the spectrum. They found no improvement in real-life social behaviors, though there was possible improvement in repetitive behaviors and in a laboratory test of emotion perception.

A third study, funded by Autism Speaks, enrolled 24 children and adolescents with ASD.  Each received 8 weeks with either oxytocin or placebo. For another 8 weeks, all 24 received the oxytocin. Though the results have not been published, they were promising enough that the National Institutes of Health awarded the research team $12.6 million for a larger study of 300 individuals, which should start enrolling next year.

Proving that a drug has positive effects can be very challenging, even for a drug that actually works. That’s why Autism Speaks and other organizations and agencies continue to fund research on oxytocin.

My bottom line is that the jury’s still out on oxytocin. I feel this way because the large, well-controlled clinical trials on its use have only just begun.

Still, I know some families will want to try oxytocin. I urge them to find a clinical trial to participate in, so that their use of oxytocin can be carefully monitored for both safety and efficacy. By participating in clinical trials, families can also help the larger autism community by contributing to the evidence that we need to fully evaluate this potential treatment. (For further guidance on participating in clinical trials, please see The Autism Speaks Participants Guide to Autism Drug Research, available for free download from this website.)

A final thought:  I question the common assumption that oxytocin helps people with autism simply by making them more affectionate and loving.  I don’t think it’s that simple. In talking and working with many families and individuals affected by autism, I have learned that people with autism don’t lack in feelings of affection and love. They want friends. They love and want to be loved in return. I think what oxytocin might do is to clear up the “mental static” and, so, make voices, language and social interactions more pleasant and understandable. Recent animal research suggests that oxytocin does this by making nerve cells fire in a cleaner, clearer way. So it may not be about making people with autism love other people more. It may be about helping them to communicate it.

You can explore all the research Autism Speaks is funding using this website’s grant searchSubscribe to Autism Speaks Science Digest for autism research news, blogs and more – delivered biweekly to your inbox.