Oxytocin, Vasopressin and Autism

Sue Carter, one of the world's top oxytocin researchers, published a new paper examining the link between oxytocin, vasopressin and autism. The paper, "Sex differences in oxytocin and vasopressin: Implications for autism spectrum disorders?," reviews the scientific literature

There are two reasons why many researchers are looking for a connection between oxytocin and autism. First, five times as many boys as girls are diagnosed with autism, and oxytocin is normally more abundant in women's bodies. Second, most of the behaviors people with autism spectrum disorder aren’t so good at are the very behaviors that oxytocin influences: picking up social cues, affection, making friends, giving and receiving physical affection.

Carter is head of the University of Illinois' Brain Body Center, and the researcher who demonstrated the link between oxytocin and bonding. She was able to switch monogamous behavior on and off by blocking oxytocin in monogamous prairie voles or injecting it into the brains of promiscuous montane voles.

She looked at not only oxytocin but also vasopressin, a related neurochemical that's less understood. While estrogen increases the effects of oxytocin, vasopressin is androgen-dependent, and males have more receptors for it in the paraventricular nucleus, a part of the brain involved in coping with stress. In animals, vasopressin influences male behaviors including reacting to challenges, protecting the nest and offspring and some parenting activities. (The assumption is that mechanisms are similar in humans.)

One hypothesis is that there are optimal vasopressin levels needed for protection against ASD. Males might be more sensitive to stress while their brains and nervous systems are under development, both in the womb and after birth. Disrupting their neurochemical balance may make them more vulnerable to ASD.

Another hypothesis is that the oxytocin-enriched female nervous system has better protection against whatever stressors cause ASD.

Carter's review of the literature found support for the connection between disruption of the vasopressin system and autism.

One interesting idea Carter floats at the end is that female coping mechanisms may keep ASD-like behaviors from becoming full-blown. She writes, "Sexually dimorphic differences in coping mechanisms, including the willingness to use social interactions to down-regulate anxiety, could be another mechanism through which males and females might differ in the expression of the features of ASD. Knowledge of natural ways to stimulate the release of endogenous oxytocin or to inhibit 'excess' vasopressin might be protective."

In other words, females naturally seek support and comfort from others (a behavior psychologist Shelley Taylor dubbed "tend and befriend" in her book, "The Tending Instinct"). Women are better at giving themselves a natural oxytocin boost, and this ability may form while they’re young enough to compensate for autistic tendencies.

Comments

[Brandon]

Leonard Shalain's book "Sex, Time, and Power" touches on autism in a section on the concepts of anima and animus. Shlain thinks of autism or Asperger's as condition in which an individual has too little anima, too little of the feminine principal so to speak. "In general, habitual criminals have too much animus, and autistic men and those diagnosed with Asperger syndrome hav too little anima."

He also proposes that this condition is more prevalent in men as a result of the difficult needle that evolution has had to thread in order to make human males both the most dangerous hunters and most nurturing fathers in the animal kingdom. Because of the polar tension of these two forces, human males have a flatter distribution curve on the anima-animus spectrum. Shlain points at this fact for evidence: "There are more gays than lesbians. There are more male psychopaths than female psychopaths."

I am curious what you think about Shlain's books, his framework for sexual difference, his framework for the occurrence of autism spectrum conditions, and whether or not his explanation could fit together with the hypothesis in your post where outside stress causes an increase in the incidence of autism.

[Susan Kuchinskas]

wow, what interesting ideas. Thanks for posting this, Brandon.

I am not sure there are more gays or male psychopaths, and I haven't read any of his books.

But based on what you say, I think his theory of anima and animus (did he get this from Jung?) dovetails quite well with the neurochemistry. You could call testosterone, which functions as a neurochemical, animus; oxytocin becomes anima. I do see oxytocin as the feminine principle, emphasizing, as Scalain seems to, that all of us have a mix of feminine and masculine in different proportions.

I find that neuroscience seems to confirm a lot of traditional philosophies and perspectives. I think neuroscience is one of many frameworks we can use to understand the human condition. Some of us prefer more metaphorical or spiritual frameworks, others (like me, I guess) prefer what I find a more pragmatic approach. But it usually seems to bring us to the same place.

I think humans probably did evolve to being cooperative breeders from the more common mammal strategy of the male scattering sperm far and wide in the hopes that some offspring would survive. And men are in a harder place as a result, as their neurochemical drives toward aggression are higher. Ideally that aggression gets channeled toward protection of family and community.

My understanding of Carter's theories (which may have evolved by this time) is that it's stressors at the neurochemical in the womb and after birth, when the oxytocin system is still developing, interfere with its proper development. So it's not necessarily that our more stressful modern world is creating more autism, but rather internal stressors, which could include the birth process, disrupt the infant brain's optimal development. Perhaps a minor distinction.

I will check out "Sex, Time and Power," thanks for the info.

[Not sure I trust you yet]

I am very interested in your research, which I've only just recently become aware. Though not officially diagnosed, I am a textbook match for the criteria of Asberger's (sp) Syndrome. I am disoriented by any social interaction, don't like to be touched, and detest small talk. Needless to say, dating is an impossibility for me, and recognizing that I am a member of a social species is a source of endless frustration. Where can I go from here? Would exposure to oxytocin make me susceptible to being fleeced, or set me up for a brave new world?

[Susan Kuchinskas]

I would think it would be more the latter. Oxytocin's effects can nudge you more in the direction of trust, it doesn't turn you into a sheep. In the experiments where people inhale oxytocin and then engage in economic games, they are MORE LIKELY to behave in a trusting manner. But even the people who are given oxytocin don't all behave more trustingly, nor do they always behave trustingly.

The researchers who are testing the use of oxytocin for symptoms of ASD have found that it improves the ability to decipher the emotional content of speech. It's also thought that it might be useful during psychotherapy or behavioral therapy sessions, to get someone "over the hump" just a bit.

In the "normal" brain, oxytocin seems to work as a social signal, saying, telling the amygdala, "this is someone who has treated me well before," or, "This person acts like other people who have treated me well in the past." It also seems to be involved in empathy, telling other parts of the brain, "This is what I would be feeling if I were that person."

There may be other things going on in Asperger's or ASD. Some people think the aversion to touch might be caused by a sort of allergic reaction to oxytocin. Instead of the oxytocin released during touch feeling good, it makes you feel sick or bad, just as eating a strawberry might make someone feel bad.

Your disorientation to social interaction may be the result of a lack of oxytocin's ability to make us feel connected, but it might also be caused (I'm speculating) by over-sensitivity to oxytocin's effects overwhelming the amygdala or other parts of the brain that make decisions about what's going on.

There will be many clinical trials in the near future to look at oxytocin's effects on the symptoms of ASD, schizophrenia, social anxiety disorder and other dysfunctions. I think your best bet would be to try to get into one of these trials, if possible. If that's not possible, hang in there until oxytocin becomes available as a medical prescription.

In the meantime, you might experiment with some kind of one-on-one psychotherapy that's experiential and would allow you to experiment with finding your boundaries for touch and talk, and then to work on expanding them a bit.