Octopuses Rolling on MDMA Reveal Unexpected Link to Humans

When the California two-spot octopus isn’t attempting to bring more eight-legged cephalopods into this world, it prefers to be alone. Known to scientists as Octopus bimaculoides, the alien-like invertebrate spends most of its time hiding or searching for food, asocial males avoiding asocial females until their biological clocks say it’s time to partner up. That is, until they are on MDMA. In a groundbreaking study released Thursday, researchers describe how octopuses on the drug act similarly to a socially anxious human on MDMA: They open up.

Gül Dölen, Ph.D., is an assistant professor of neuroscience at Johns Hopkins University and the co-author of the new Current Biology paper. She tells Inverse that when octopuses are on MDMA, it’s like watching “an eight-armed hug.”

“They were very loose,” Dölen says. “They just embraced with multiple arms.”

While MDMA is known to trigger prosocial behavior in mice and humans, it has never been witnessed in invertebrates, animals that have no backbone. Vertebrates and invertebrates have wildly divergent bodies and brain structures, and for a long time scientists didn’t think the latter had the capacity to be social. They only recently realized invertebrates deserved a second look.

Because of improvements in molecular genetic analysis, Dölen explains, we’re beginning to understand the ways in which both groups evolved from a common ancestor. The findings of the new study add evidence to the idea that social behaviors have a long evolutionary history — going back much farther than we ever believed. The electrifying results could significantly impact what we know about the evolution of brains and why MDMA-assisted therapy seems to be such a useful tool in treating post-traumatic stress disorder and anxiety.