Researchers studied DNA from over 41,000 people in the Paisa population of Colombia. They linked seven genes to serious mental illness and found one ADAP1 variant that raises risk of schizophrenia and bipolar disorder more than threefold.
Most known risk genes for mental illness are either very common with tiny effects or extremely rare with large ones. This variant sits in between, and it changes how illness looks: carriers show distinct psychotic, manic, and thinking symptoms, including weaker executive function. That could let doctors sort patients by underlying cause, not just by diagnosis.
✦ Genetics is starting to explain not just who gets mental illness, but which kind.