Nature Study Finds Shared Genetic Roots Across Major Psychiatric Disorders

A large genome‑wide study led by Texas A&M University and published in Nature finds that many common psychiatric conditions share overlapping genetic influences rather than being genetically isolated disorders. Researchers analyzed DNA from more than one million people diagnosed with 14 childhood and adult‑onset psychiatric conditions and from five million controls, grouping the illnesses into five clusters such as compulsive disorders, schizophrenia–bipolar, neurodevelopmental disorders, internalizing disorders like depression and anxiety, and substance‑use disorders. They identified 238 small genetic differences tied to these patterns, with traits such as suicidal thoughts and loneliness linked across all five clusters, and found that internalizing disorders are more strongly associated with cells that speed brain signaling, while schizophrenia–bipolar disorders show stronger links to cells that send "go" signals between brain regions. Co‑author John Hettema, M.D., Ph.D., said the results could eventually support treatments that target multiple related disorders instead of treating each in isolation. Outside experts note that while genes "set the stage," environmental factors still determine whether and how these conditions emerge, and the work underscores that mental illness is rooted in brain biology rather than being purely behavioral or moral in nature.