In a meta-analysis of 24 epidemiological studies of anxiety disorders, the estimated mean age of onset for anxiety disorders was 21.3 years.1 As evidenced by the nonoverlapping confidence intervals of their estimates, separation anxiety disorder, specific phobia, and social anxiety disorder have a significantly earlier onset than other anxiety disorders, and generalized anxiety disorder has a significantly later onset compared with separation anxiety disorder, specific phobia, and social anxiety disorder, and with agoraphobia without panic disorder, and OCD.1
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