Separation distress
Normally infants display a separation distress. That is, infants exhibit behaviors that indicate they are uncomfortable when away from caregivers. They are acutely aware of their parents’ proximity. This is also known as “stranger anxiety” as they display these behaviors when unknown individuals hold them, or are in closer proximity than their mothers. Such behaviors may include reaching for their caregivers if they are near, crying, and attempting to make more contact with their parents.
Infants with autism do not display such behaviors. They do not seem concerned when their parents are not near. Infants with autism exhibit less crying than infants without autism (Gillberg, 1995).
Connections with Opioids (distress)
Brain opioids inhibit separation distress, and opioid antagonists exacerbate distress. Since there are increased levels of opioids in autistic individuals, we would anticipate them to show less separation distress. However, it is still not understood whether these increased levels are due to overproduction of opioids, or underproduction of opioid antagonists. An antagonist is anything that decreases the likelihood of an event occurring. Therefore, opioid antagonists are substances that decrease the likelihood of opioids being activated or produced, thus they block opioids. As such, decreased levels of opioid antagonists would decrease separation distress.
The evidence that ties opioids with separation distress in autism is indirect insofar as they have been displayed in some animals. Morphine, a type of opiate, decreases infant-maternal proximity maintenance time in animals (Herman & Panksepp, 1978).
Other opiate-treated animals have displayed less clinging (Gillberg, 1995).
Questions and Answers about the Research (#1)
Social Communicative Intent
The desire to communicate in young children is shown through nonverbal communication. The interest in social activity can be displayed by eye contact, smiling, and pointing as if to show. This is important developmentally as it promotes care giving, and closeness between the child and parent.
Autistic infants and children fail to smile or point as if to show (Bartak, Rutter, & Cox). They fail to make eye contact, and do not generally orient towards others. Instead, the communication that is displayed appears to serve primarily for biological functional purposes. They seem to use people as “object tools” (Sahley & Panksepp, 1987). The distinction is quite critical in diagnosing autism. Autistic children are not entirely unaware of other people, but instead do not engage social activities for the sake of sociality. They have a low desire for social companionship and fail to express physical affection.
Connections with Opioids (emotion)
Opioids appear to regulate emotional/motivational states. Opioids, or endorphins, are thought to be released from social interaction. There may be a neurological desire to engage in social activity. However, what might happen if an individual had increased levels of opioids, regardless of social interaction? This would mean that without social interaction, the individual is neurologically self-stimulated. For example, the good feeling that an infant experiences when smiling back at its smiling father may be influenced by opioids being released. If a child, such as children with autism do, has increased levels of opioids, they would not seek interactions that would increase their good feeling as they already are self-stimulated.
In a way, people with opioid addictions serve as an experiment. What happens when there are increases in opiates exogenously in humans? People that are addicted to opiates, morphine users for example, display a reduced socialization and aloofness (Gillberg, 1995). This is not direct evidence, however, researchers suggest it points future investigators to study this link further.
Pharmacological alteration of opioid tone in experimental animals has been shown to reduce the desire for social companionship. This means that when animals were given opiate treatments, much like in the study discussed in the previous section, the animals were less interested in engaging socially.
Questions and Answers about Research (#2)
Average children engage in self-stimulating behaviors like thumb sucking, lip chewing, and tongue rolling. They are assumed to have a soothing effect (Jankovic, 1988). Autistic children display more intense self-stimulating behaviors such as lip biting, head banging, and scratching. They seem to be less sensitive to pain as they engage in self-abusive behavior. Self-injurious behavior is defined as behavior which produces physical injury to the individual’s own body.
*For more in depth descriptions of self-injurious behavior, click on one of the case reports below. As these are detailed accounts and fairly graphic,, please enter at your own discretion.*
Case Reports #1, 2, 3: Examples of self injurious behavior
Connections with Opioids (self-injurious behavior)
There are two hypotheses related to opioids connection with self-injurious behavior in autism (Walters et al., 1990).
#1: The Down-Regulation Hypothesis (Sandman et al., 1983)
This involves the idea that excess endogenous opioids result in a absence or dampening of pain. As previously discussed, opioids create a good feeling. If there is abnormally high level of good feeling, injury that is normally processed as painful may not be sensitive for the autistic individual.
#2: The Opiate-Addiction Hypothesis (Richardson & Zaleski, 1983; Sandman et al., 1983)
This idea entails the fact that opioids are generally released during painful experiences. A common example is the “runner’s high” that people experience after exercising for an extensive period of time. This is caused by an influx of endorphins, a type of opiate. Thus, the autistic individual engages in self-injury to promote the increase of opioids. They already experience opiate hyperactivity (more activity). Thus, they continually search for opportunities to stimulate opioid release.
Using these hypotheses Walters et al. (1990) treated a 14-year-old autistic and mentally retarded male for his self-injurious behavior with naltrexone hydrochloride, an opiate antagonist. During his second phase of treatment the boy displayed less self-injurious behavior. Thus, the researchers suggest that there may be a link between self-injurious behavior and opioids. The results, however, do not distinguish support between the two hypotheses.