The epidemiology of anxiety disorders: prevalence and societal costs.

Anxiety disorders are the most prevalent of psychiatric disorders, yet less than 30% of individuals who suffer from anxiety disorders seek treatment. Prevalence of anxiety disorders is difficult to pinpoint since even small changes in diagnostic criteria, interview tools, or study methodology affect results. Analyses of the largest prevalence studies of psychiatric illnesses in the United States find that anxiety disorders afflict 15.7 million people in the United States each year, and 30 million people in the United States at some point in their lives. Currently, the European Study of Epidemiology of Mental Disorders and the World Health Organization World Mental Health 2000 studies are underway. These studies, which share a similar methodology, will facilitate future worldwide comparisons of the prevalence of anxiety disorders. Anxiety disorders impose high individual and social burden, tend to be chronic, and can be as disabling as somatic disorders. Compared with those who have other psychiatric disorders, people with anxiety disorders are high care utilizers who present to general practitioners more frequently than to psychiatric professionals, placing a strain upon the health care system. The economic costs of anxiety disorders include psychiatric, nonpsychiatric, and emergency care; hospitalization; prescription drugs; reduced productivity; absenteeism from work; and suicide.