Bidirectional Association between First-Episode Panic Disorder and Major Depressive Disorder in a Nationwide General Population Survey in Korea.

Background: Panic disorder (PD) and major depressive disorder (MDD) can occur concurrently, despite different clinical manifestations. Because MDD and PD patients tend to have more complicated conditions, understanding the co-occurrence and pattern of these conditions is important. Here, we investigated the influence of PD and MDD on each other, with respect to time interval.