It's well recognized that cognitive deficits in childhood or adolescence typically precede the onset of psychosis, but the studies done up until now have not determined whether the association is prodromal (an early symptom of psychosis itself) or neurodevelopmental (problems with brain development and maturation that set the stage for later psychosis). A study just published in JAMA Psychiatry offers strong evidence that verbal decline in adolescence reflects neurodevelopmental defects that significantly increase the lifetime risk for psychosis.