A new study published in the Proceedings of the National Academy of Sciences suggests that a marijuana-like drug could help people with autism socialize more.

It's well-known that marijuana has an effect on human social behavior, but perhaps it's less known that humans have marijuana-like chemicals in their brain. One such chemical is anandamide, a class of other naturally occurring chemicals known as endocannabinoids (also the source of your runner's high). Anandamide attaches to the same brain cell receptors as marijuana's active ingredient THC, with the entire endocannabinoid system working to regulate "the reinforcement of various natural stimuli as well as neurotransmission from the part of the brain called the nucleus accumbens."

Interested to see if this system "might cooperate with oxytocin to control social award," researchers isolated a juvenile group of mice for 24 hours and then either returned them to their group or left them in isolation for an additional three hours. The social mice exhibited higher levels of anandamide in the ventral hippocampus and nucleus accumbens, two brain regions associated with motivated behavior in mice. These levels then triggered cannabinoid receptors to reinforce what researchers call "the pleasure of socialization." What’s more is when these receptors were blocked, the "pleasurable reinforcement" disappeared.

Given that the nucleus accumbens has "recently been implicated in the regulation of social reward by the hypothalamic neuropeptide oxytocin," researchers then set out to see if anandamide could be linked back to oxytocin; you may know of oxytocin as the love or cuddle hormone. The brain makes and uses oxytocin as a neurotransmitter, and in mice, stimulating this hormone led to an increase in anandamide creation in the nucleus accumbens. And again, when researchers blocked anandamide's effects, it also blocked the pro-social effects of oxytocin.

Put it another way: in mice, researchers have found that an oxytocin-dependent endocannabinoid signal contributes to the regulation of social reward, making for more a more pleasurable, not anxious social experience. This provides deeper insight to how oxytocin interacts with other modulatory systems that work to regulate the rewarding properties of social behavior.

This is where autism comes into play. The disorder is characterized by "social-interaction difficulties, with most children who develop autism having difficult engaging in the give-and-take of everyday human interactions," non-profit organization Autism Speaks reported.

The non-profit continued: "Subtle social cues such as a smile, wave or grimace may convey little meaning…Without the ability to interpret gestures and facial expressions, the social world can seem bewildering."

The present study suggests that the oxytocin-driven anandamide signaling may be defective in those with autism — and if there were a drug that could correct this deficit, it may offer a new social strategy.

Source: Wei D, et al. Endocannabinoid signaling mediates oxytocin-driven social reward. PNAS. 2015.