To experience anxiety is normal. However, clinical anxiety is tension or apprehension that is grossly disproportionate to an actual or perceived stimulus. The source of anxiety may not be apparent and indeed may not be external; an underlying biochemical defect and genetic predisposition are hypothesized.
Clinical anxiety, whether chronic or in the form of a panic attack, often produces somatic symptoms, impedes normal functioning, and adversely affects the quality of life. The disorders are approximately twice as common (possibly more often reported) in women than in men. The age at onset is usually between 20 and 30 years. Both endogenous and external factors likely contribute to susceptibility and expression of the clinical problem. Common adult anxiety disorders include generalized anxiety disorder, social phobia, OCD, panic disorder, and posttraumatic stress syndrome. Drugs for treating anxiety disorders, or anxiolytics, include benzodiazepines and buspirone.