Cognitive-Behavioral Therapy and Escitalopram for Generalized Anxiety Disorder(GAD)

Overview

The goals of this pilot study are as follows: 1\) To disseminate and examine the effectiveness of a manualized, individual, cognitive-behavioral psychotherapy (CBT) for adults with Generalized Anxiety Disorder(GAD), 2) to test the effectiveness of augmentation (the addition of) antidepressant therapy in participants who do not fully respond to CBT, and 3) to examine individual and clinical predictors of non-response to CBT and predictors of response to augmentation antidepressant therapy. A related goal is to examine the maintenance of treatment gains obtained from CBT alone and CBT with augmentation antidepressant therapy, over a twenty-four month follow-up period. This study will serve as a pilot investigation in preparation for a larger federally funded study using this treatment approach. We hypothesize that CBT will result in remission (no longer having GAD) and/or high endstate functioning (clinically meaningful improvement) in approximately 40-50% of participants. Further, we hypothesize that augmentation antidepressant therapy in participants who do not fully respond to CBT will result in further clinically significant improvement.

This pilot investigation will examine the effectiveness of augmenting cognitive behavioral therapy (CBT) with antidepressant pharmacotherapy (escitalopram\[Lexapro\]) in adults with generalized anxiety disorder (GAD) who do not fully respond to a temporally primary trial of CBT. A secondary aim of this study is to assess the maintenance of treatment gains made by patients in response to CBT, and to CBT with antidepressant augmentation therapy, over a two-year follow-up period. CBT is an empirically supported psychotherapy that has been found to be effective in treating GAD in approximately 50 percent of patients enrolled in controlled clinical trials. However, a substantial proportion (nearly half) of individuals with GAD do not achieve full remission or clinically significant improvement at the cessation of CBT. Escitalopram (Lexapro)is a selective serotonin reuptake inhibitor (SSRI) antidepressant, which has been shown to be effective in treating GAD in several large-scale controlled clinical trials. The Food and Drug Administration has approved ecitalopram for the treatment of GAD. The proposed research plan encompasses the conduct of an open clinical trial (No randomized placebo control) of 14 sessions of manualized individual CBT for persons meeting DSM-IV-TR diagnostic criteria for GAD. This study will use a treatment manual developed by Dr. Thomas Borkovec and colleagues at the Pennsylvania State University. Participants who meet high endstate functioning criteria and/or achieve remission following CBT will be evaluated periodically during a twenty-four month follow-up phase. Participants who do not meet high endstate functioning criteria and/or achieve remission following completion of CBT will be offered entry into a twelve-week, open-label, flexible-dose trial of escitalopram therapy. Participants receiving escitalopram therapy will be evaluated periodically during a twenty-four month follow-up phase, as well. It is anticipated that patients who do not fully respond to CBT will show a significant increment in improvement in GAD symptoms, over and above their CBT posttreatment level, following pharmacotherapy with escitalopram. At present, no studies with GAD populations have examined the additive or sequenced effects of psychosocial therapy and SSRI antidepressant pharmacotherapy. The proposed research is a first step in this direction and may provide evidence supporting the use of combined treatment modalities in CBT partial and non-responders.