Results Summary

What was the research about?

People with anxiety disorders may feel fear, worry, or nervousness. These feelings can make doing daily activities hard. Certain medicines can help reduce anxiety, but people may have side effects or other problems taking them. Meditation can also help reduce anxiety.

In this project, the research team compared two treatments for patients with anxiety disorders:

  • Mindfulness-based stress reduction, or MBSR. MBSR is a type of meditation. Patients took an MBSR course for eight weeks. They learned about different forms of MBSR and how to practice meditation. They also received guided practice sessions on meditation for home use.
  • Escitalopram, a medicine for anxiety. Doctors prescribed this medicine for eight weeks. Patients took 10 milligrams (mg) per day by mouth during week one. Doctors increased the dose to 20 mg per day during week two if the patient didn’t have bad side effects.

The research team first wanted to learn if MBSR wasn’t worse than the medicine in reducing anxiety. The team also compared MBSR delivered in person before the COVID-19 pandemic with MBSR delivered online during the pandemic.

What were the results?

After eight weeks, when delivered in person, MBSR worked about the same as the medicine to reduce anxiety symptoms. Both treatments reduced patients’ anxiety symptoms. Also, online MBSR worked about the same as in-person MBSR.

Among patients who received the medicine, 79 percent had at least one side effect compared with 15 percent of patients who received MBSR. The most common side effects for the medicine were insomnia or sleep disturbances, nausea, and fatigue. The most common side effect for MBSR was increased anxiety during treatment.

Who was in the study?

The in-person study included 208 patients, and the online study included 197 patients. Patients had different types of anxiety, including general, social, panic attacks, or fear of crowds. Among patients, 59 percent were White, 20 percent were Asian, 16 percent were Black, and 7 percent were another race; 9 percent were Hispanic or Latino. The average age was 34, and 76 percent were women. All received care at one of three health centers in Washington, DC, New York City, and Boston.

What did the research team do?

The research team assigned patients by chance to receive MBSR or the medicine. Patients had regular check-ins with a clinician, such as a doctor or nurse, during the study. During the pandemic, the team repeated the study and delivered treatments online.

At four and eight weeks, an independent clinician assessed patients’ anxiety symptoms. The clinician didn’t know which treatment patients received.

Patients with anxiety disorders, clinicians, a healthcare system representative, and an anxiety disorder outreach organization helped design the study.

What were the limits of the study?

Most patients in the study were women and had a college degree. Results may differ for patients of other backgrounds.

Future research could include patients of other backgrounds.

How can people use the results?

Doctors and patients can use the results when considering treatments for anxiety disorders.

Final Research Report

This project's final research report is expected to be available by June 2024.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers agreed that this is a strong study and an impactful report overall but had some questions related to heterogeneity of treatment effects (HTE) analyses. First, they noted that the HTE analyses were only brought up in the discussion and asked the researchers to add information about the HTE analyses to sections of the report related to study aims, methods and results. The reviewers also highlighted discrepancies regarding the description of non-significance in HTE results when there appeared to be significant differences in treatment effectiveness between males and females. The authors explained that their study lacked sufficient power to confidently conclude whether different subgroups benefited differently from the interventions. The authors explained that they wanted to present their results, despite the lack of power, to demonstrate the potentially larger improvements for males and older age groups across treatments.
  • The reviewers noted that the primary analyses were to test non-inferiority of mindfulness-based stress reduction (MBSR) treatment to escitalopram, where the question was whether MBSR performs worse than escitalopram. However, the researchers seemed to report on the differences between groups, reflecting a question of whether or not the two interventions performed the same. The authors acknowledged that their presentation of results could be confusing because it was based on a null hypothesis of equivalence between treatments rather than whether MBSR had worse outcomes than escitalopram, and revised their results accordingly.
  • The reviewers requested a brief explanation in the introduction section elucidating the distinctions between MBSR-type interventions and Cognitive Behavioral Therapy (CBT), as well as rationale for choosing one over the other. The authors described the differences between these two treatment modalities and justified their selection of MBSR over CBT by pointing out that CBT has been extensively compared to medication in various large-scale anxiety treatment studies but MBSR has not. 
  • The reviewers sought clarification on the target population of anxiety patients for this study and recommended aligning it with the exclusion criteria outlined in the report. The authors clarified that any person with an anxiety disorder who met the other inclusion/exclusion criteria was eligible, regardless of whether they were newly diagnosed or had a chronic disorder. 
  • The reviewers asked the researchers to provide more details about the outcome measures they chose, including the rationale for choosing these measures and the meaning of a one-unit difference on the scales. The researchers added text to their descriptions of the outcomes to explain that each outcome measured slightly different constructs and these constructs could have different meanings for different patients. The researchers also provided more psychometric and scoring information for the scales they used in order to make the actual differences on those scales more meaningful to readers.

Conflict of Interest Disclosures

Project Information

Elizabeth Hoge, MD
Georgetown University Medical Center
Comparative Effectiveness of Mindfulness-Based Stress Reduction and Pharmacotherapy for Anxiety

Key Dates

November 2017
June 2023

Study Registration Information


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Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
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Last updated: March 14, 2024