We identified a class with minimal symptoms over time (41.7%), a moderately severe chronic class (42.8%), and a severe chronic class (15.4%). Panic disorder with agoraphobia (OR = 2.14; 95% CI, 1.48-3.09) and social phobia (OR = 1.97; 95% CI, 1.46-2.68) predicted moderately severe chronicity; panic disorder with agoraphobia (OR = 2.70; 95% CI, 1.66-4.40), social phobia (OR = 2.46; 95% CI, 1.62-3.74), and generalized anxiety disorder (OR = 1.86; 95% CI, 1.23-2.82) predicted a severe chronic course