Anxiety Disorders

Introduction

Anxiety disorders represent a major global mental health problem and are the most prevalent category of psychological disorders in the United States, with a lifetime prevalence estimate of 28.8%. Similar estimates have been reported in surveys from Canada, Great Britain, Australia, and the Netherlands. The overall economic impact of anxiety disorders in the United States has been estimated [Page 40]to be over $42 billion per year, or an annual cost of over $1,500 per individual with an anxiety disorder. Direct psychiatric treatment and pharmaceutical costs represent 31% and 2% of the total costs, respectively. Workplace costs, the majority of which stem from lost productivity, represent 10% of the total cost. Over 50% of the total costs result from direct non-psychiatric medical costs, which are believed to result from medical treatment based on non-diagnosis or improper diagnosis. Thus, most of the annual economic impact of anxiety disorders can be avoided or eliminated by proper diagnosis and by the proliferation of effective and accessible treatment options. Indeed, many treatments with documented efficacy for anxiety disorders exist, including pharmacological and psychotherapeutic options.

Despite the wealth of research on anxiety and anxiety disorders, uncertainty exists regarding where to draw the line between separate diagnoses as well as thresholds for determining clinical severity. Indeed, although evidence strongly suggests that the experience of anxiety and fear is universal, cultural variations in the presentation and prevalence of specific fears highlight the non-universality of current diagnostic classification.

Defining and Diagnosing Anxiety

Fear and anxiety are considered normal emotional or cognitive-affective states that are part of the defensive motivational system. Fear is seen as the response to a perceived immediate threat and is typically characterized by an intense physiological response (fight or flight), focused attention on the perceived threat, and an escape motivation. Anxiety serves as the defensive system that scans for possible or future threats and involves a less pronounced physiological response, increased cognitive activity to detect threat (e.g., hypervigilance, worry), and increased avoidance motivation. Although these are normal responses designed to protect the individual from immediate or future threats, in some individuals the responses can become sufficiently excessive that they cause significant impairment or distress and are termed anxiety disorders.

In the most recent revision of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR), 12 distinct anxiety disorder diagnoses are codified; this is a dramatic increase over previous editions. Currently, the DSM-IV-TR includes panic disorder without agoraphobia, panic disorder with agoraphobia, agoraphobia without history of panic disorder, specific phobia, social phobia, obsessive-compulsive disorder, acute stress disorder, generalized anxiety disorder, post-traumatic stress disorder, anxiety disorder due to a general medical condition, substance-induced anxiety disorder, and anxiety disorder not otherwise specified. While it is acknowledged that the DSM system is not perfect, particularly for anxiety disorders, many would argue that it provides a sufficient framework.

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