Perseverative thought: A robust predictor of response to emotional challenge in generalized anxiety disorder and major depressive disorder

► Perseverative thought (PT) was evaluated as a shared risk process for GAD and MDD. ► We defined PT as negative, dyscontrolled thinking, without regard to thought content. ► PT prospectively predicted adverse responses to a laboratory stressor. ► PT had substantial incremental validity as a predictor over diagnostic status. ► PT was associated with the presence and severity of GAD and MDD.