Anxiety disorders in the USA, 1990 to 1997 - Trend in complaint, diagnosis, use of pharmacotherapy and diagnosis of comorbid depression

Objective: To discern the trend in the prevalence and population-adjusted r ate of US office-based physician visits documenting a diagnosis of anxiety among patients greater than or equal to 18 years of age. Design: This was a retrospective study of data from a large national survey in the USA. Methods: Data from the National Ambulatory Medical Care Survey for the year s 1990 through 1997 were used for this analysis. Anxiety was defined as Int ernational Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes 300.00 to 300.02. Subcategories included: (i) anxiety, uns pecified type (300.00); (ii) panic disorder (300.01); and (iii) generalised anxiety disorder (GAD) [300.02]. Office visits resulting in a diagnosis of anxiety were partitioned into four time intervals for trend analysis: 1990 to 1991; 1992 to 1993; 1994 to 1995; 1996to 1997. Results: The annualised mean number of office visits documenting a diagnosi s of anxiety increased from 5 739 390 in 1990-1991 to 8 429 413 in 1996-199 7. The majority of patients were female, aged between 40 and 59 years, and White. On average, 44.4% of patients were prescribed an antianxiety medicat ion. The proportion of patients with a concomitant diagnosis of depression increased from 7.1 to 12.8%. Use of antidepressants increased from 16.2 to 34.2% of patients, with use of a selective serotonin reuptake inhibitor inc reasing more than 5-fold. The proportion of patients prescribed both an ant ianxiety medication and an antidepressant increased from 7.4 to 13.8%. Ther e existed a 1.4-fold increase in the population-adjusted rate of office vis its documenting a diagnosis of anxiety, rising from 30.8 office visits per 1000 US population greater than or equal to 18 years old in 1990-1991 to 42 .8 per 1000 in 1996-1997; a 1.2-fold increase in anxiety of unspecified typ e, from 23.2 to 28.7 per 1000; panic disorder more than doubled, from 4.5 t o 9.5 per 1000; and GAD increased from 3.3 to 5.2 per 1000. Conclusion: The high prevalence of anxiety disorders, predominant in women, represents a major public health concern. Previous research suggests that anxiety disorders are associated with a decreased quality of life, an incre ased rate of cardiovascular/cerebrovascular events, and an increased risk o f mortality due to suicide. Further research is required to discern the rea sons for the growth in the prevalence of anxiety disorders, and to examine the effectiveness of medical management.