TORONTO— Controlled clinical studies are invaluable for identifying the most reliable diagnostic tools and giving hard evidence on a treatment’s effectiveness. But evidence-based studies can rarely replicate the myriad situations that a treating physician encounters in his or her office on a daily basis.

Short- and long-term treatments for panic disorders have been established in double-blind placebo controlled trials. Unfortunately, patients in the real world offer more complex situations than those that can be addressed in a controlled clinical trial.

Eric D. Peselow, MD, a psychiatrist at the New York University School of Medicine, spoke at the 159th Annual Meeting of the American Psychiatric Association about "real-world" conditions he’s encountered while treating patients with panic disorders and how they differ from the patients recruited for controlled clinical studies. In most cases, he said, clinicians must respond with a variety of strategies to alleviate panic attacks.

Dr. Peselow and his team analyzed 1,047 patients treated over the last 13 years at the Freedom From Fear clinic in Staten Island, New York. Affiliated with Columbia University, the clinic screens patients from all over the country, many of them with "difficult cases," said Dr. Peselow. "Whereas patients in a research trial are more homogenous, are treated with only one drug, and generally have no comorbidities, clinicians treating patients at panic disorders clinics may encounter patients with one or more comorbid conditions on a daily basis," he elaborated.

RESPONSE, BUT NOT RETENTION

For his analysis, Dr. Peselow gathered information from each patient’s chart, medical history, pain inventory, and through a modified SCID (Structured Clinical Interview for DSM-IV Dissociative Disorders).

Of the 1,047 patient cases reviewed, 680 patients had completed nine to 12 weeks of treatment and were free of panic attacks for at least eight weeks. Of these, 304 patients (44%) had received nonbiologic therapy (primarily cognitive behavioral therapy) in addition to pharmacologic treatment.

After three months, 64 of the 680 patients who had recovered with no full-blown panic attacks had either relapsed (n = 45) or dropped out of treatment (n = 19). Six months later, 68 more had relapsed (n = 48) or dropped out (n = 20). One year after initial recovery, 57 more had relapsed (n = 36) or dropped out of treatment (n = 21).

Five years after initial successful treatment, approximately 100 patients were still on the therapy, said Dr. Peselow, often with the same medication and dose. In most cases, though, response from a medication dissipates after a year, he noted.

CHARACTERIZING NONRESPONDERS

Among the 367 patients who did not respond to treatment, only 11.2% had panic disorder alone. Thirty-nine percent had panic disorder plus two other anxiety disorders; 27% had panic plus depression; and 22% had panic plus one other generalized anxiety disorder.

Nonresponders—like responders—were treated with cognitive behavioral therapy with or without pharmacologic therapy (most often the antidepressants paroxetine, sertraline, or escitalopram), and in some cases in combination with an anxiolytic agent or mood stabilizer.

Only 34% of the nonresponders completed "a reasonable course of treatment," said Dr. Peselow. Remaining patients had dropped out of the treatment for various reasons. Most commonly, these included refusal to take medication, bad side effects of medication, or they simply did not return after first or second visit, he added.

THE COMPLEXITY OF REAL-WORLD CASES

Making panic disorder treatment even more complex, Dr. Peselow said that personality disorders and depression often "gets tainted with Axis I symptoms." Over 13 years, 404 clinic patients had been diagnosed with personality disorders in addition to panic; nearly half of those (45%) had an A, B, or C cluster disorder.

When encountering a patient with panic disorder, treating physicians do not have "elegant manualized training, videotapes, or critiques by cognitive behavioral therapy therapists," to draw from, said Dr. Peselow. "What we need are more pragmatic real-world studies."

—Kathlyn Stone

Suggested Reading
Bakker A, van Balkom AJ, Stein DJ. Evidence-based pharmacotherapy of panic disorder. Int J Neuropsychopharmacol. 2005;8:473-482.
Otto MW, Deveney C. Cognitive-behavioral therapy and the treatment of panic disorder: efficacy and strategies. J Clin Psychiatry. 2005;66 suppl 4:28-32.

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