Researchers have identified miR-124 signaling and its effects on AMPA receptor neurotransmission as a biological mechanism linking the shared risk scores of schizophrenia and bipolar disorders to their shared symptoms. The work, which appeared online in Neuron on Nov. 14, 2022, focused on schizophrenia and bipolar disorder, which are both highly heritable disorders that share substantial risk. Beyond their implications for those two specific disorders, the findings illustrate a path to connecting risk scores and behaviors via their biological link.