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The superstar of the hour, however, is the family of antidepressant drugs known as SSRIS (selective serotonin re-uptake inhibitors). There is evidence linking panic disorder to a serotonin deficiency, and these compounds appear to work by boosting serotonin levels. The best known of all this family is Prozac, Eli Lilly's $2.1 billion-a-year baby, which has become a societal catchword for relief from anxiety. But another family member, Paxil (manufactured by SmithKline Beecham), is the first to be approved by the fda specifically for the treatment of panic disorder. While drug therapy by itself is successful in 70% of cases--the same rate as cognitive behavioral therapy alone--preliminary, unpublished research suggests that the success rate might climb as high as 90% when the treatments are combined. But Gorman cautions that this needs to be studied in more detail.
Nonetheless, says Dr. Una McCann, head of the unit on anxiety and affective disorders at the NIMH, "serotonin is obviously not the whole story. If it were, the SSRIS would not take two to four weeks to kick in." Recently, some researchers have begun to eye a naturally occurring chemical called cholecystokinin (CCK), an anxiety-causing compound that binds to receptors in the brain stem as well as the gut. This dual affinity may explain the butterflies-in-the-stomach sensations that often herald panic attacks. CCK-mimicking compounds trigger attacks in panic-disorder patients but not in normal volunteers, so a likely candidate for a new panic-disorder pill would be a drug that blocks CCK.
Other anxiety disorders appear to share a common fear circuitry in the brain and are treated by similar methods. Generalized anxiety disorder, for example, is different from panic disorder in that it does not strike suddenly but follows a predictable pattern of worries and fears. In social phobias, the trigger is an exaggerated dread of public embarrassment. "These people have panic attacks only in specific situations, such as writing a check in public, using public rest rooms or eating out," explains McCann.
The multifaceted SSRIS have also dramatically altered the treatment of depression, which remains the most common form of mental illness. Although no more efficacious than traditional antidepressants, they do not produce many of the unpleasant side effects, such as sedation and weight gain, that have caused thousands of potential patients to shun treatment. "SSRIS have revolutionized, and continue to revolutionize, the comfort levels with which psychiatrists and family practitioners treat depression," says Dr. David Kupfer, chairman of psychiatry at the University of Pittsburgh School of Medicine. "Suddenly, physicians are more willing to prescribe these medications for people who truly need them, and people suffering from a depression are more willing to take them and stay on them."
Even patients who have been chronically depressed for five years or more respond well in 65% to 70% of cases, Kupfer points out, and recent research underlines the importance of remaining on the medications long enough to prevent a relapse. "New studies show that the dosage that got you better will keep you better," he says. "Depression is a chronic, lifelong illness, and we're beginning to think of these drugs as being similar to insulin for diabetes."