Anxiety Disorders: Generalized Anxiety Disorder
In the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) (American Psychiatric Association, 1994) GAD is currently defined as excessive anxiety and worry (apprehensive expectation) occurring for a majority of days dur-ing at least a 6-month period, about a number of events or ac-tivities (such as work or school performance; see DSM-IV). In individuals with GAD, the anxiety and worry are accompanied by at least three of six somatic symptoms (only one accompany-ing symptom is required in children), which include restlessness or feeling keyed up or on edge, being easily fatigued, difficulty concentrating or mind going blank, irritability, muscle tension and sleep disturbance. In addition, the affected individual has difficulty controlling his/her worry, and the anxiety, worry, or somatic symptoms cause clinically significant distress or im-pairment in social, occupational, and/or other important areas of functioning. Further, the GAD symptoms should not be due to the direct physiological effects of a substance such as drugs or alcohol or a general medical condition, and should not occur exclusively during a mood disorder, psychotic disorder, or perva-sive developmental disorder.
Worry and anxiety are part of normal human behavior and it may be difficult to define a cutoff point distinguishing normal or trait anxiety (i.e., a relatively stable tendency to perceive vari-ous situations as threatening) from GAD. However, as described in the DSM-IV definition of GAD, individuals suffering from a “disorder” exhibit significant distress and impairment in func-tioning as a result of their anxiety symptoms.