Anxiety Disorders
Anxiety disorders include panic disorder, obsessive-compulsive disorder, post-traumatic stress disorder, generalized anxiety disorder, and phobias (social phobia, agoraphobia, and specific phobia).

•   Approximately 40 million American adults ages 18 and older, or about 18.1 percent of people in this age group in a given year, have an anxiety disorder.
•   Anxiety disorders frequently co-occur with depressive disorders or substance abuse.
•   Most people with one anxiety disorder also have another anxiety disorder. Nearly three-quarters of those with an anxiety disorder will have their first episode by age 21.5.

Panic Disorder

•   Approximately 6 million American adults ages 18 and older, or about 2.7 percent of people in this age group in a given year, have panic disorder.
•   Panic disorder typically develops in early adulthood (median age of onset is 24), but the age of onset extends throughout adulthood.
•   About one in three people with panic disorder develops agoraphobia, a condition in which the individual becomes afraid of being in any place or situation where escape might be difficult or help unavailable in the event of a panic attack.

Obsessive-Compulsive Disorder (OCD)

•   Approximately 2.2 million American adults age 18 and older, or about 1.0 percent of people in this age group in a given year, have OCD.
•   The first symptoms of OCD often begin during childhood or adolescence, however, the median age of onset is 19.

Post-Traumatic Stress Disorder (PTSD)

•   Approximately 7.7 million American adults age 18 and older, or about 3.5 percent of people in this age group in a given year, have PTSD.
•   PTSD can develop at any age, including childhood, but research shows that the median age of onset is 23 years.
•   About 19 percent of Vietnam veterans experienced PTSD at some point after the war. The disorder also frequently occurs after violent personal assaults such as rape, mugging, or domestic violence; terrorism; natural or human-caused disasters; and accidents.

Generalized Anxiety Disorder (GAD)

•   Approximately 6.8 million American adults, or about 3.1 percent of people age 18 and over, have GAD in a given year.
•   GAD can begin across the life cycle, though the median age of onset is 31 years old.

Social Phobia

•   Approximately 15 million American adults age 18 and over, or about 6.8 percent of people in this age group in a given year, have social phobia.
•   Social phobia begins in childhood or adolescence, typically around 13 years of age.