Anxiety: A Very Short Introduction - Daniel Freeman, Jason Freeman 2012

How common is panic disorder?
Panic disorder

Around one in five people have experienced an unexpected panic attack, generally at times of severe stress. Panic disorder, though, is believed to affect around 2% of the population at any one time. When it comes to lifetime risk, the US National Comorbidity Survey Replication reported that 3.7% of adults had at some point experienced panic disorder, and a further 1.1% panic disorder with agoraphobia.

Panic disorder generally develops in adulthood, with surveys suggesting an average age of about 22 for onset. However, the US National Comorbidity Survey Replication Adolescent Supplement found that 2.3% of teenagers aged 13 to 18 reported having experienced the disorder at some point.

Panic disorder is yet another anxiety disorder that is much more common in women than in men — by a ratio of two to one in this case.