To be diagnosed with GAD, one must experience this excessive anxiety for the majority of days during a period of six months or longer. Most of those with GAD claim to have felt anxious for their entire lives, and the disorder is often first seen in childhood or adolescence. However, adult onset of the disorder is not uncommon. Other anxiety disorders Certain persons can experience anxiety in response to a general medical condition or from substance abuse. Others exhibit certain signs of particular anxiety disorders without meeting all the criteria for an official diagnosis.
Anxiety disorders are the most common mental illnesses in the United States.
It is quite common for one anxiety disorder to coexist with another or several others. In fact, it is estimated that over half of those diagnosed with panic disorder or OCD have depression too. Several factors seem to contribute to the development of an anxiety disorder. Much new research suggests that these disorders both run in families and are the result of one's brain chemistry. Certain life experiences and one's general personality are also thought to influence the likelihood of having an anxiety disorder.