Generalized anxiety disorder (GAD) is the most common of the anxiety disorders. It has a lifetime prevalence of 5.7% and an annual prevalence of 3.1% in the United States. But, these rates could increase dramatically if new diagnostic criteria for GAD are established.

Currently, the Diagnostic and Statistical Manual of Mental Disorders (DSM), the handbook for all diagnostics in the field of psychiatry, defines GAD as “anxiety and worry that is excessive and difficult to control and that occurs more days than not for a period of at least 6 months.” GAD also includes symptoms of fatigue, restlessness, irritability, sleep disturbances, decreased concentration and memory, and muscle tension. The DSM is due for an update, and changes to these diagnostic criteria are being debated.

GAD was first included in the DSM-III in 1980. At that time, it was a catch-all diagnosis for disorders that did not fit in another category. The duration of symptoms required for diagnosis was only 1 month. The DSM-IV, published in 1994, increased the duration of symptoms to 6 months. Now, the work group assigned to revamp the criteria proposes returning to only 1 month of symptoms for a diagnosis of GAD. No studies have proven that 6 months is a clinically meaningful timeframe, and owing to the significant morbidity and cost associated with GAD, a 1-month criterion could be appropriate to treat more people with the disorder. If this change is accepted, the annual prevalence of GAD would likely double.

In addition to changing the duration criterion, the work group is considering changing some of the symptoms associated with GAD. Sleep disturbance and irritability would be deleted from the list, since they are insufficiently specific. Also, dimensional attributes would be introduced to the criteria in addition to the current categorical attributes. The work group also plans to rename the disorder “Generalized Worry Disorder” to highlight the hallmark symptom of the disorder.

GAD is associated with a plethora of comorbidities, including many other psychiatric disorders. Of patients with GAD, 62% are also diagnosed with a major depressive disorder at some point in their lives. Dysthymia, substance abuse, other anxiety disorders, and bipolar disorder are also common comorbidities. GAD is a chronic disorder that requires long-term therapy to completely resolve the symptoms and functional impairment and improve quality of life. Currently, many people who might benefit from treatment are not diagnosed, and, therefore, not treated. An analysis of the possible criteria changes found that the prevalence of GAD would rise, but the severity of the diagnoses would not change.

Part of the controversy that surrounds the new diagnostic criteria is whether or not GAD should be a stand-alone entity at all. GAD precedes depression as often as depression precedes GAD, and the symptoms of the two disorders are remarkably similar, as are the risk factors and treatment options.  Still, even undiagnosed, patients suffering from both disorders suffer impaired quality of life and increased use of the healthcare system.

Whether or not the new changes to the GAD diagnostic criteria will be accepted remains to be seen. If they are, many more people may benefit from earlier intervention and treatment of a costly and debilitating disorder.

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