Effectiveness of Long-Term Versus Short-Term Treatment of Generalized Anxiety Disorder With Venlafaxine XR
This study will assess the effectiveness of venlafaxine XR in preventing the relapse of generalized anxiety disorder after 6 months of treatment versus 12 months of treatment.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Short-term Versus Long-term Treatment in Generalized Anxiety Disorder|
- Relapse of GAD [ Time Frame: Meausured at Months 6, 12, and 24 ] [ Designated as safety issue: No ]
- Anxiety, depression, and GAD symptoms [ Time Frame: Measured at Months 6, 12, 18, and 24 ] [ Designated as safety issue: No ]
|Study Start Date:||January 2004|
|Study Completion Date:||September 2009|
|Primary Completion Date:||September 2009 (Final data collection date for primary outcome measure)|
Drug: Venlafaxine XR
All participants will take venlafaxine for 6 months. After this initial 6 months, participants who are not randomized to placebo will continue to take venlafaxine.
Venlafaxine and placebo
Drug: Venlafaxine XR
All participants will take venlafaxine for 6 months. After this initial 6 months, participants who are not randomized to placebo will continue to take venlafaxine.Drug: Placebo
After initial treatment with venlafaxine, some participants will be randomized to take placebo for 6 months in the second phase of the study and then to switch back to venlafaxine or continue with placebo for an additional 6 months.
Generalized anxiety disorder (GAD) is a highly prevalent, chronic psychiatric disorder. Despite the fact that GAD frequently demands prolonged treatment with medication, very little is known about the benefits of long-term treatment. GAD is characterized by 6 months or more of exaggerated worry and tension that is unfounded or much more severe than the normal anxiety most people experience. People with GAD are unable to relax and often suffer from insomnia. Venlafaxine XR, a drug used to treat depression, has been shown to be effective in the short-term treatment of GAD. However, its benefits over a course of more than 8 weeks have not been assessed. This study will evaluate the effectiveness of venlafaxine XR in treating GAD on a long-term basis and preventing the relapse of GAD after 6 months of treatment versus 12 months of treatment.
Participants in this double-blind study will first receive 6 months of open-label treatment with venlafaxine XR. Upon completion of this initial phase, participants will be randomly assigned to either continue on venlafaxine XR or begin taking placebo. After 12 months, participants taking venlafaxine XR will be randomly assigned to continue on the drug or switch to placebo. Participants will have 22 study visits over at least 18 months. Follow-up visits will occur 24 months after enrollment. Relapse of GAD will be assessed with the Hamilton Anxiety Scale and Global Severity and Improvement Scale. A variety of methods, including questionnaires and standardized scales, will be used to assess secondary outcomes.
|United States, Pennsylvania|
|University of Pennsylvania, 3535 Market Street, Suite 670|
|Philadelphia, Pennsylvania, United States, 19104-3309|
|Principal Investigator:||Karl Rickels, MD||University of Pennsylvania|