Panic disorder is a common psychiatric condition with significant associated morbidity and disability. Both psychopharmacologic agents and cognitive-behavioral therapies have been shown to be successful treatments. Recent research has promoted selective serotonin reuptake inhibitors (SSRIs) as first-line therapy for panic disorder, specifically sertraline, because of its effectiveness in treating depression and obsessive-compulsive disorder. Pollack and associates conducted a randomized, double-blind, flexible-dose study to determine the effectiveness of varying dosages of sertraline in the treatment of patients with panic disorder.

Patients eligible for the study were at least 18 years of age and met the criteria for panic disorder, with or without agoraphobia, as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R). They had to have experienced panic attacks before the study and during a two-week placebo washout period before treatment commenced. In addition, patients in the study had a minimum score of 18 on the Hamilton Anxiety Scale and no signs of substantial depression. Patients were excluded if they had a history of other psychiatric conditions, such as major depression, bipolar disorder or schizophrenia, and a recent history of substance abuse or regular use of benzodiazepines.

Patients were randomized to receive either 25 or 50 mg of sertraline or placebo. Dosages were gradually adjusted weekly, depending on the patient's response, to a maximum dosage of 200 mg per day. Follow-up visits were scheduled weekly for the first month and biweekly for the remainder of the 10-week study period. Laboratory studies, including hematology and serum chemistries, were performed at baseline and at the end of weeks 2 and 10.

A total of 176 patients were included in the study (88 patients in each group). There were no significant differences in baseline demographics or severity of depression among the study participants. Compared with patients in the placebo group, patients in the treatment group experienced a significant reduction in panic attacks by the end of the second week; this pattern continued through the end of the study. These patients also had a greater reduction in anxiety ratings as measured by several instruments, both during and at the end of the study. There were no significant differences in the overall incidence of adverse effects between patients treated with placebo and those treated with sertraline.

The authors conclude that sertraline is a safe, effective and well-tolerated short-term treatment for patients with panic disorder, with or without agoraphobia. Sertraline reduced the frequency of panic attacks and the global severity of the illness. While few adverse effects developed, the authors suggest initiating therapy with 25 mg of sertraline per day to minimize early treatment withdrawal related to side effects. Future research that examines the effectiveness of longer-term therapy is needed to evaluate whether the observed clinical benefits are maintained.

editor's note: This study adds to a growing body of literature that supports the efficacy and tolerability of SSRIs in the treatment of panic disorder, as well as other symptoms of anxiety. The difficulty in clinical practice has been maintaining patients until the correct dosage of the SSRI is attained and clinical benefit occurs. Some physicians have successfully overlapped therapy with a short course of a benzodiazepine while titrating the dose of the SSRI.—j.t.k.