Current Research Studies

MDMA-assisted Therapy Versus Cognitive Processing Therapy for Veterans with Severe Posttraumatic Stress Disorder (MDMA v CPT)

Principal Investigators:

Trisha Suppes, MD, PhD
Shannon Wiltsey Stirman

This study is being done together by researchers at VA Palo Alto Healthcare System and Stanford University

Status: not yet recruiting participants.


Posttraumatic Stress Disorder (PTSD) is a serious condition that significantly impacts a person's daily life, which can lead to functional impairment, psychosocial disability, and the risk of suicide. The Department of Veterans Affairs (VA) currently serves over two million Veterans with PTSD. In this clinical research study, we aim to compare two treatments—MDMA-assisted therapy (MDMA-AT) and Cognitive Processing Therapy (CPT)—for Veterans with PTSD. 

Our goal is to learn how MDMA-AT compares to CPT in reducing PTSD symptoms among Veterans. Additionally, we will assess the feasibility and health economics of implementing MDMA-AT versus CPT within the VA system. This study will provide valuable insights into the potential use of MDMA-assisted therapy for PTSD treatment in the VA. 

What is involved?

Participation in the research study is expected to last approximately 24 to 26 weeks and will involve a total of 16 to 18 visits. These visits will be a combination of virtual and in-person sessions held in Palo Alto, CA. 

Participants will be randomly assigned to receive either MDMA-AT or CPT. Those assigned to CPT may have the option to receive MDMA-AT after completing all CPT sessions. Those assigned to MDMA-AT can choose to receive CPT within the VA system after finishing the MDMA-AT sessions. 

What is MDMA-Assisted Therapy (MDMA-AT)? 

MDMA-assisted therapy is a novel treatment that combines psychotherapy with the administration of MDMA (3,4-methylenedioxymethamphetamine). The purpose of this treatment is to enhance certain aspects of therapy. This involves three sessions during which MDMA is used, along with ‘preparatory’ and ‘integration’ sessions without the use of medication. 

What is Cognitive Processing Therapy (CPT)? 

Cognitive Processing Therapy is a treatment approach developed by Dr. Patricia Resick in the late 1980s. It focuses on cognition (thoughts and beliefs about traumatic experiences) and is effective in treating PTSD. Extensive research on CPT has been conducted within the VA system, demonstrating promising outcomes. Currently, it is considered the gold standard treatment for PTSD in the VA. CPT typically consists of 8 to 15 one-hour weekly treatment sessions, accompanied by homework assignments to practice the skills taught in each session. 

Comparing CPT and MDMA-AT for the treatment of PTSD is particularly important due to the urgent need for effective treatments within the VA system.  

Are you a Veteran living with PTSD? 

If you are a Veteran interested in participating in this study, please email or call the screening line at (650) 849-0161 for more information. 

Find out more about this clinical trial here.

*For complaints, concerns, or participant's rights, contact 1-866-680-2906.

The Safety and Efficacy of Psilocybin in Participants With Treatment Resistant Depression (P-TRD)

Principal Investigators

Trisha Suppes, MD, PhD, VA Palo Alto Health Care System and Stanford University School of Medicine
Scott Aaronson, MD, Sheppard Pratt Health System (co-investigator)

This study is no longer recruiting participants.

Study Description

A study to determine the optimal therapeutic dose of Psilocybin in Treatment Resistant Depression (TRD). The main purpose of this study is to test how well psilocybin works to lessen depressive symptoms. We will do this by studying the effect of a single dose of 25mg of psilocybin. Your depressive symptoms will be measured by a change in your score for a questionnaire that looks at your depressive symptoms. Psilocybin is a controlled drug and a chemical compound found in some species of mushrooms. Recent studies have suggested that psilocybin may help in treating depression and we wish to investigate this further. Psilocybin works on the serotonin system in the brain which is linked to the regulation of mood. Current regulations do not allow psilocybin to be prescribed in the United States for treating depression, although it has been approved for use in this research study. This research study is expected to take approximately 2 years to complete. You may require additional visits if you need a longer time to stop your antidepressant medication.


Psilocybin3-[2-(Dimethylamino)ethyl]-1H-indol-4-yl dihydrogen phosphate

Eligibility Inclusion Criteria

  • Are you a Veteran? 
  • Are you between the age of 18 and 66 at screening?
  • Do you currently have a diagnosis of treatment resistant depression?
  • Are you willing to discontinued all antidepressant and/or antipsychotic medications at least 2 weeks prior to baseline (V2).
  • Are you able to complete all protocol required assessment tools without any assistance, and to comply with all study visits?
  • Are you able to have a companion available to accompany the participant up to 4 visits with the participant, including the day of the psilocybin session, and be able to drive you home?

If ALL are yes, please see following exclusion criteria.

Eligibility Exclusion Criteria

Psychiatric Exclusion Criteria

  • Some psychiatric illnesses, such as psychotic disorders, are an exclusion to entering this study.  
  • Are you currently participating in a cognitive behavioral therapy (CBT)?
  • Do you currently have alcohol or substance abuse?
  • Have you been diagnosed with depression determined to be secondary to other severe medical conditions?
  • Do you have any other personal circumstances and behavior judged to be incompatible with establishment of rapport or safe exposure to psilocybin, including exposure to psilocybin within the past year and use of psychedelics, such as ayahuasca during the current depressive episode?

General Medical Exclusion Criteria:

  • Are you or your partner pregnant, nursing, or planning a pregnancy?
  • Do you have any unstable medical conditions?
  • Are you willing to perform urine drug screen for illegal or drugs of abuse ?
  • Are you currently enrolled in any investigational drug or device study or participation in such within 30 days?