A surprising link between the immune system and brain behavior is emerging, as new research reveals how a single immune molecule can affect both anxiety and sociability depending on which brain region it acts upon.

Scientists found that IL-17 behaves almost like a brain chemical, influencing neuron activity in ways that alter mood and behavior during illness. These findings suggest the immune system plays a much deeper role in shaping our mental states than previously thought, opening new doors for treating conditions like autism and anxiety through immune-based therapies.

Immune Molecules and Brain Behavior.