One recent study examined remission rates for different anxiety disorders after cognitive behavior therapy (CBT). A meta-analysis of 100 different studies, the authors found an overall remission rate of 51% (though with varying definitions of remission). Remission rates varied depending on how the original authors defined remission, diagnosis, age, and other characteristics (such as medication use).
Which disorders had the lowest remission rate? Obsessive-compulsive disorder (OCD) and social anxiety disorder (SAD). The highest remission rate? Post-traumatic stress disorder (PTSD).
OCD is thought to have a strong biological basis- perhaps the strongest of the anxiety disorders. Medication is often considered necessary. With social anxiety disorder, there is perhaps a characterological component that requires extended work to address.
In contrast, a diagnosis of PTSD requires a specific, external event. This traumatic event is central to the formation of the disorder, and the key component of CBT treatment of PTSD is prolonged exposure to the event. In this way, perhaps CBT treatment of PTSD is more "direct" than OCD and SAD leading to more significant overall remission rates.