Suzanne M. Sutherland, M.D.

The term anxiety refers to many states in which the sufferer experiences a sense of impending threat or doom that is not well defined or realistically based.

Anxiety can be adaptive or pathologic, transient or chronic, and has a variety of psychological and physical manifestations. Anxiety disorders are a heterogeneous group of disorders in which the feeling of anxiety is the major element. They are the most prevalent group of psychiatric disorders; according to the Epidemiological Catchment Area study, 7.3% of all Americans meet the Diagnostic and Statistical Manual of Mental Disorders, 3rd edition (DSM-III; the DSM version used at the time) criteria at a given point in time (so-called point prevalence). Anxiety disorders listed in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) are shown in Table 3-1.

Anxiety disorders, the most prevalent psychiatric illnesses in the general community, are present in 15 to 20% of medical clinic patients. Anxiety, defined as a subjective sense of unease, dread, or foreboding, can indicate a primary psychiatric condition or can be a component of, or reaction to, a primary medical disease. The primary anxiety disorders are classified according to their duration and course and the existence and nature of precipitants.

When evaluating the anxious patient, the clinician must first determine whether the anxiety antedates or postdates a medical illness or is due to a medication side effect. Approximately one-third of patients presenting with anxiety have a medical etiology for their psychiatric symptoms, but an anxiety disorder can also present with somatic symptoms in the absence of a diagnosable medical condition.