Effectiveness of Long-Term Versus Short-Term Treatment of Generalized Anxiety Disorder With Venlafaxine XR

November 29, 2016 updated by: Karl Rickels, University of Pennsylvania

Short-term Versus Long-term Treatment in Generalized Anxiety Disorder

This study will assess the effectiveness of venlafaxine XR, randomized to either venlafaxine XR or placebo in preventing the relapse of generalized anxiety disorder after 6 months of treatment versus 12 months of treatment.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

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.

Study Type

Interventional

Enrollment (Actual)

268

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104-3309
        • University of Pennsylvania, 3535 Market Street, Suite 670

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • GAD diagnosis by structured interview
  • Hamilton Anxiety Scale score of 18 or MORE
  • Clinical Global Impressions Severity Scale score of at least 4
  • Hamilton Depression Scale score of 18 or less
  • Hamilton Depression Scale suicide item score less than 2
  • Use of an effective form of contraception throughout the study

Exclusion Criteria:

  • Hypersensitivity to venlafaxine XR
  • History of seizures
  • Episode of major depressive disorder in the previous 6 months
  • History of any psychotic illness, bipolar disorder, or dementia
  • Substance abuse and dependence during the past 6 months
  • Other anxiety disorders with the exception of social phobia as long as GAD is primary
  • Regular use of anxiolytics or antidepressants within 7 days of study onset
  • Use of fluoxetine or monoamine oxidase inhibitors within 28 days of study onset (low dose usage of benzodiazepines will not prevent participation)
  • Use of other psychotropic medication besides benzodiazepines during the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Open-Label Group
6-month randomized phase of Venlafaxine XR at a flexible dose of 75 - 225 mg/d
Drug: Venlafaxine XR
Six month intervention of Venlafaxine XR treatment with flexible range of 75 to 225 mg/d
Other Names:
  • Effexor
  • Effexor XR
  • Trevilor
  • selective serotonin and norepinephrine reuptake inhibitors
  • Venlafaxine hydrochloride extended release
  • Lanvexin
Active Comparator: Double-Blind Drug Group
6-month randomized, double-blind phase of Venlafaxine XR at a flexible dose of 75 - 225 mg/d occurring between months 6 - 12 of the study
Drug: Venlafaxine XR
Six month intervention of Venlafaxine XR treatment with flexible range of 75 to 225 mg/d
Other Names:
  • Effexor
  • Effexor XR
  • Trevilor
  • selective serotonin and norepinephrine reuptake inhibitors
  • Venlafaxine hydrochloride extended release
  • Lanvexin
Placebo Comparator: Double-Blind Placebo Group
6-month randomized, double blind phase of placebo occurring between months 6 - 12 of the study
Drug: Placebo
six month intervention with placebo drug
Active Comparator: Double-Blind Drug-After-Drug Group
6-month randomized, double blind phase of Venlafaxine XR at a flexible dose of 75 - 225 mg/d occurring between months 13 - 19 of the study
Drug: Venlafaxine XR
Six month intervention of Venlafaxine XR treatment with flexible range of 75 to 225 mg/d
Other Names:
  • Effexor
  • Effexor XR
  • Trevilor
  • selective serotonin and norepinephrine reuptake inhibitors
  • Venlafaxine hydrochloride extended release
  • Lanvexin
Placebo Comparator: Double-Blind Placebo-After-Drug Group
6-month randomized, double blind phase of placebo occurring between months 13 - 19 of the study
Drug: Placebo
six month intervention with placebo drug
Placebo Comparator: Double-Blind Placebo-After-Placebo Group
6-month randomized, double blind phase of placebo occurring between months 13 - 19 of the study
Drug: Placebo
six month intervention with placebo drug

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Hamilton Rating Scale for Anxiety
Time Frame: Measured at Months 6 (Open Label), 12 (Double-Blind), and 18 (Double-Blind Relapse)

Hamilton Rating Scale for Anxiety - The assessment of anxiety states by rating

Each item is scored on a scale of 0 (not present) to 4 (severe), with a total score range of 0-56, where <17 indicates mild severity, 18-24 mild to moderate severity and 25-30 moderate to severe.
Measured at Months 6 (Open Label), 12 (Double-Blind), and 18 (Double-Blind Relapse)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical Global Impressions, Severity of Illness
Time Frame: Measured at Months 6 (Open Label), 12 (Double-Blind), 18 (Double-Blind, and 24 (Double-Blind Relapse)

The CGI provides an overall clinician-determined summary measure that takes into account a knowledge of the patient's history, psychosocial circumstances, symptoms, behavior, and the impact of the symptoms on the patient's ability to function.

The CGI is rated on the following seven-point scale: 1=normal, not at all ill; 2=borderline mentally ill; 3=mildly ill; 4=moderately ill; 5=markedly ill; 6=severely ill; 7=among the most extremely ill patients.

Results of the "Placebo After Placebo" group in Phase 3 were not entered due to sample size limitations.
Measured at Months 6 (Open Label), 12 (Double-Blind), 18 (Double-Blind, and 24 (Double-Blind Relapse)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Pennsylvania

Collaborators

National Institute of Mental Health (NIMH)

Investigators

  • Principal Investigator: Karl Rickels, MD, University of Pennsylvania

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2004

Primary Completion (Actual)

September 1, 2009

Study Completion (Actual)

September 1, 2009

Study Registration Dates

First Submitted

September 12, 2005

First Submitted That Met QC Criteria

September 12, 2005

First Posted (Estimate)

September 16, 2005

Study Record Updates

Last Update Posted (Estimate)

January 16, 2017

Last Update Submitted That Met QC Criteria

November 29, 2016

Last Verified

November 1, 2016

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MH65963
  • R01MH065963 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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