Remission rates in patients with anxiety disorders treated with paroxetine

Background: Approximately 50% to 60% of patients with depression and/or anxiety respond to treatment, but only a minority achieve remission. The continued presence of subsyndromal symptoms in treated depressed (and probably anxious) patients leads to higher relapse rates and increased utilization of health care resources. It is proposed that remission is the appropriate target in the treatment of both depression and the anxiety disorders. Aims: Rigorous criteria for remission have been proposed for the anxiety disorders and are currently being applied in clinical studies. Using these criteria, data from the paroxetine clinical study database were retrospectively analyzed to determine remission rates following paroxetine treatment across a range of anxiety disorders in the largest analysis of remission data in the anxiety disorders to date. Method: These analyses included data from 16 short-term and 6 long-term, randomized, placebo-controlled studies in panic disorder, social anxiety disorder, obsessive-compulsive disorder, posttraumatic stress disorder (short term only), and generalized anxiety disorder (DSM-III-R or DSM-IV). Separate analyses were performed for each disorder, with short- and long-term data analyzed separately. Results: In general, across the range of anxiety disorders studied, in both short- and long-term studies, remission rates were higher for paroxetine compared with placebo, using disorder-specific, global, and functional remission criteria both individually and combined. Remission occurred in a moderate proportion of paroxetine-treated patients after only 8 to 12 weeks of treatment, and longer-term therapy led to even higher remission rates. Conclusion: Paroxetine has demonstrated efficacy in treating patients to remission across the range of anxiety disorders studied. Our findings strongly suggest that continuing treatment with paroxetine (and probably other SSRI antidepressants) for 2 to 12 months increases the proportion of patients achieving clinical remission.