For decades, the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM), with its universal set of standards, has been widely considered the best tool for classifying and diagnosing mental illness. But medical psychiatry may be overdue for a biological revolution. In this Aeon interview, the US-based neuroscientist Claire Gillan describes breakthroughs in brain science that suggest mental illnesses should be reclassified, and explains how brain-scanning technologies that investigate the underlying biology could lead to more effective mental health therapies. Read the paper on Gillan’s research here.