Sertraline treatment of panic disorder: response in patients at risk for poor outcome

More than one third of panic disorder patients have a chronic and/or recurrent form of the disorder, accounting for much of the individual and societal cost associated with the illness. Six clinical variables have been most consistently identified as high-risk predictors of poor outcome: (1) panic severity, (2) presence of agoraphobia, (3) comorbid depression, (4) comorbid personality disorder, (5) duration of illness, and (6) female sex. No published research has systematically examined the differential antipanic efficacy of selective serotonin reuptake inhibitors in patients at high risk for poor outcome.

Data were pooled (N = 664) from 4 double-blind, placebo-controlled studies of the efficacy of sertraline for the treatment of DSM-III-R panic disorder. Two of the studies were 12-week fixed-dose studies with starting daily doses of sertraline, 50 mg, and 2 were 10-week flexible-dose studies with starting daily doses of sertraline, 25 mg. All other study design features were the same, except for the exclusion of women of childbearing potential in the 2 fixed-dose studies. Exclusion of patients with marked personality disorders and depression meant that only 4 of the poor-outcome variables could be evaluated.

Clinical improvement was similar for patients treated with sertraline whether or not they carried an agoraphobia diagnosis, had a duration of illness > 2 years, or were female. Patients with high baseline panic severity had significantly (p = .01) less improvement on the endpoint Clinical Global Impressions-Improvement (CGI-I) scale than patients with moderate severity, although the Clinical Global Impressions-Severity of Illness scale change score was higher in the patients with high severity (-2.00 vs. -1.31). For patients with 3 or more high-risk variables, there was a modest, but statistically significant, tendency for reduced global improvement (endpoint CGI-I score of 2.7 for the high-risk vs. 2.4 for the non-high-risk group; p = .017), although the high-risk group actually had a similar endpoint reduction in frequency of panic attacks (82%) compared with the non-high-risk group (78%).

Treatment of panic disorder with sertraline was generally effective, even in the presence of baseline clinical variables that have been associated with poor treatment response. The main limitations of the analysis were the reliance on pooled data from 4 studies (even if the designs were similar) and our inability to examine the impact of depression and personality disorders on response to treatment because of the exclusion criteria of the clinical trials.