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After studying this chapter, the student should be able to:

  • Understand the basic biological mechanisms involved in the pathogenesis of anxiety disorders.

  • Review the prevalence and severity of anxiety disorders.

  • Understand the basic biological, psychological, and social factors that may render a person vulnerable to an anxiety disorder.

  • State the various basic treatments of anxiety disorders.

Although anxiety is a normal emotion experienced by essentially everyone at some point in their lives, patients with anxiety disorders experience prolonged or abnormally intense feelings of anxiety that cause significant distress or impairment. In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V), these disorders are grouped into 3 categories. The first category, anxiety disorders, includes panic disorders, generalized anxiety disorder (GAD), and several disorders with anxiety caused by specific stimuli (including separation anxiety disorder, a childhood condition discussed in Chapter 44). The obsessive-compulsive disorders category includes obsessive-compulsive disorder, hoarding, and body dysmorphic disorder (the latter is discussed in Chapter 41 because it is considered a somatic disorder in the 10th revision of the International Statistical Classification of Diseases and Related Health Problems, ICD-10). The third category, trauma- and stressor-related disorders, includes posttraumatic stress disorder (PTSD).


Anxiety is a common feeling or emotion experienced by most people. In general, anxiety disorders have the highest prevalence of all psychiatric conditions, with a lifetime prevalence of approximately 25%. Phobias (specific phobia and social anxiety disorder/phobia) are the most common mental disorders in the United States. At least 5% to 10% of the population and possibly as much as 25% of the population may suffer from some type of a phobic disorder (eg, fear of needles, animals, heights). Prevalence estimates of anxiety disorders are generally higher in developed countries than in developing countries. Many anxiety disorders are more prevalent in women than in men, with a ratio of 2:1, except obsessive-compulsive disorder and social anxiety disorder, in which the female-to-male ratio is closer to 1:1. Most anxiety disorders start in childhood.

Studies have estimated the annual cost of anxiety disorders in the United States to be approximately $42.3 billion in the 1990s, a majority of which was due to nonpsychiatric medical treatment costs, per the Centers for Disease Control and Prevention. This estimate focused on short-term effects and did not include the effect of outcomes such as the increased risk of other disorders. Anxiety can be severely debilitating and can cause significant suffering and social isolation.


Social Anxiety Disorder (Social Phobia)

Social anxiety disorder, also known as social phobia, is a marked fear or anxiety about 1 or more social situations in which the individual is exposed to possible scrutiny by others. The fear, anxiety, or avoidance is persistent and typically present for ≥6 months. Examples include fear of ...

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