Glutamate Imaging and Cognitive Testing for Depression

Overseen By Sarah B, MA

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Yale University

Must not be taking: Anticoagulants

Disqualifiers: Significant medical illness, Suicidal ideation, Metallic devices, Substance use, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to understand the role of the brain's glutamate system in depression. Participants will undergo MRI (Magnetic Resonance Imaging) and PET (Positron Emission Tomography) scans to capture brain images, along with cognitive tests to evaluate thinking skills. The trial seeks individuals with depression or PTSD who are either medication-free or on specific medications, and who do not have other major health issues. Participants must have experienced a current depressive episode or PTSD symptoms, and participation may last 1-2 months. As an unphased trial, this study offers a unique opportunity to contribute to groundbreaking research that could lead to new insights into mental health conditions.

Do I need to stop my current medications to join the trial?

The trial requires participants to be medication-free for at least 2 weeks or to be on a permissible medication. The protocol does not specify which medications are permissible, so you may need to discuss your current medications with the study team.

Will I have to stop taking my current medications?

The trial requires participants to be medication-free for at least 2 weeks or to be taking a permissible medication. You may need to stop taking your current medications if they are not allowed in the study.

What prior data suggests that the MRI and PET scans are safe for participants?

Previous studies have shown that MRI (Magnetic Resonance Imaging) is safe for people. MRI uses strong magnets and radio waves to create detailed pictures of the body's organs and tissues, without using radiation, making it a low-risk imaging option.

PET (Positron Emission Tomography) scans use a small amount of radioactive material to assess how the body functions. Research on PET imaging indicates it is generally safe, though it involves exposure to low levels of radiation. The radiation amount is typically within safe limits and similar to other medical imaging tests.

Both MRI and PET are well-tolerated by most people. Some may experience mild discomfort, such as feeling enclosed during an MRI or a slight pinch from the injection for a PET scan. Overall, strong safety evidence supports the use of both methods in clinical settings. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it uses advanced brain imaging techniques like MRI and PET scans to better understand depression. Unlike standard treatments that focus on altering neurotransmitter levels with medication, this approach aims to visualize brain chemistry and structure directly, offering a non-invasive way to observe changes in the brain's glutamate system. By combining these imaging techniques with cognitive assessments, researchers hope to uncover new insights into how depression affects brain function, potentially leading to more personalized and effective treatment options in the future.

What evidence suggests that this trial's treatments could be effective for depression?

Research has shown that MRI (Magnetic Resonance Imaging), a technique used in this trial, can help predict how well someone might respond to depression treatment. One study found that analyzing MRI data with machine learning accurately predicted treatment success 84% of the time and correctly identified 77% of those who would benefit. This suggests that MRI can effectively forecast who might benefit from depression treatments. Similarly, PET (Positron Emission Tomography) scans, another technique used in this trial, can predict treatment response by identifying specific brain activity patterns. Both imaging techniques are becoming valuable tools in personalizing and improving treatment plans for depression. ^{2 3 5 6 7}

Who Is on the Research Team?

Irina Esterlis, PhD

Principal Investigator

Yale University

Are You a Good Fit for This Trial?

This trial is for adults aged 18-65 with certain psychiatric conditions like depression, bipolar disorder, or PTSD. It's also open to healthy individuals without any DSM-5 diagnosis. Participants must be English-speaking and medication-free or on approved meds for at least two weeks.

Inclusion Criteria

I haven't taken any medication for the last 2 weeks or only allowed medications for depression.

I haven't taken any medication in the last 2 weeks or only allowed medications for PTSD.

Subjects must be English speaking

Exclusion Criteria

Have given a blood donation within eight weeks of the start of the study

I have a bleeding disorder or am on blood thinners like Coumadin.

Have history of prior radiation exposure for research purposes within the past year such that participation in this study would place them over FDA limits for annual radiation exposure. This guideline is an effective dose of 5 rem received per year

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

1 visit (in-person)

Imaging and Testing

Participants undergo MRI and PET scans, and participate in cognitive testing

1-2 months

2-3 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after imaging and testing

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Cognitive Testing
• MRI
• PET

Trial Overview The study examines the glutamate system in mental health by using PET scans, MRI imaging, and cognitive tests over 1-2 months. The goal is to understand how this system differs among those with psychiatric disorders compared to healthy controls.

How Is the Trial Designed?

Group I: Cognitive Testing Experimental Treatment 1 Intervention

Cognitive assessments

Group II: Magnetic Resonance Imaging Active Control 1 Intervention

All subjects will have one MRI with a possibility of one functional MRI (fmri).

Group III: Positron Emission Tomography Active Control 1 Intervention

All subjects will have PET scan using FPEB or ABP688.

Who Is Running the Clinical Trial?

Yale University

Lead Sponsor

Trials

1,963

Recruited

3,046,000+

VA Office of Research and Development

Collaborator

Trials

1,691

Recruited

3,759,000+

Published Research Related to This Trial

In a study of 98 adults with unipolar depression who had not responded to previous antidepressants, a single infusion of intravenous ketamine significantly enhanced neuroplasticity within 24 hours, as measured by changes in gray matter microstructure using diffusion tensor imaging (DTI).

Greater neuroplasticity, indicated by a decrease in DTI mean diffusivity (DTI-MD), was associated with larger improvements in depression scores, particularly in the left BA10 and left amygdala regions, suggesting that ketamine's rapid antidepressant effects may be linked to its ability to promote neuroplastic changes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Rapid neuroplasticity changes and response to intravenous ketamine: a randomized controlled trial in treatment-resistant depression. Kopelman, J., Keller, TA., Panny, B., et al.[2023]

Ketamine has shown rapid antidepressant effects in several well-controlled studies and is also beneficial for conditions like post-traumatic stress disorder and obsessive-compulsive disorder, although these effects are often short-lived after single infusions.

While ketamine is considered safe for occasional use at sub-anesthetic doses, concerns about neurotoxicity, psychotomimetic effects, and potential for addiction highlight the need for further research on the safety of prolonged use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Has psychiatry tamed the "ketamine tiger?" Considerations on its use for depression and anxiety. Rasmussen, KG.[2015]

In a study of 10 patients with major depressive disorder, those who responded to ketamine treatment showed higher fractional anisotropy (FA) in specific brain regions compared to non-responders, suggesting that white matter microstructure may influence treatment outcomes.

Non-responders exhibited distinct changes in white matter metrics, such as decreased FA and increased radial diffusivity (RD) in certain pathways, indicating that structural differences in the brain could potentially predict who will benefit from ketamine therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Structural connectivity and response to ketamine therapy in major depression: A preliminary study. Vasavada, MM., Leaver, AM., Espinoza, RT., et al.[2018]

Intravenous ketamine has been shown to be safe and effective in rapidly reducing depressive symptoms, including suicidal thoughts, in patients with treatment-resistant unipolar or bipolar depression, based on five controlled studies and additional open-label studies.

While ketamine shows promise as a short-term antidepressant therapy, further research is needed to assess its long-term safety and effectiveness, as well as the efficacy of alternative administration routes like oral or intranasal.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ketamine for the treatment of depression. Howland, RH.[2022]

In a small study of 7 patients with treatment-resistant depression, a single IV ketamine infusion was associated with increased GABA levels in the anterior cingulate cortex, which correlated with improvements in depression symptoms the next day.

These findings suggest that GABA neurotransmission may play a key role in ketamine's antidepressant effects, highlighting the potential for developing GABA-related biomarkers to predict treatment response in larger studies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A preliminary study of the association of increased anterior cingulate gamma-aminobutyric acid with remission of depression after ketamine administration. Singh, B., Port, JD., Voort, JLV., et al.[2021]

Major depression is linked to diffuse neuromodulatory mechanisms rather than permanent changes in brain connectivity, with significant effects on mood and behavior stemming from the fronto-striatal regions of the brain.

In older patients, major depression is associated with structural brain abnormalities and cognitive impairments, particularly in memory, which are reflected in reduced blood flow to frontal, temporal, and parietal brain areas.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Neuropsychological and neuroimaging evidence for the involvement of the frontal lobes in depression. Goodwin, GM.[2022]

Structural neuroimaging studies have consistently shown that individuals with major depressive disorder have reduced volumes in key brain areas such as the prefrontal lobe, hippocampus, and amygdala, which may contribute to the disorder's symptoms.

Functional imaging reveals decreased activation in the dorsolateral prefrontal cortex and increased activity in the amygdala and other regions during depressive episodes, suggesting that these brain areas are crucial for emotion regulation and that successful treatment can normalize these abnormalities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[The anatomy of depression in light of evidence from neuroimaging studies]. Jaracz, J.[2009]

Ketamine and esketamine are effective for rapidly alleviating symptoms of treatment-resistant depression, with esketamine being approved for use in the US and EU, while ketamine is often used off-label.

Both treatments may require repeated doses and the addition of standard antidepressants to sustain their effects, but they also carry risks of adverse effects and potential for abuse, highlighting the need for further research on their long-term safety and efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Pharmacotherapy: Ketamine and Esketamine. Feeney, A., Papakostas, GI.[2023]

Excessive glutamate release is linked to stress and neurodegenerative diseases, and abnormalities in glutamatergic neurotransmission are significant in major psychiatric disorders like schizophrenia and depression.

Ketamine, an NMDA antagonist, shows rapid antidepressant effects for treatment-resistant depression, highlighting the potential of new antidepressants targeting the glutamate system, as supported by recent human studies using advanced imaging techniques.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Glutamatergic Dysfunction and Glutamatergic Compounds for Major Psychiatric Disorders: Evidence From Clinical Neuroimaging Studies. Li, CT., Yang, KC., Lin, WC.[2020]

Ketamine has emerged as a promising treatment for major depressive disorder, especially for patients who are resistant to other therapies, showing rapid reductions in depressive symptoms and suicidal thoughts at subanesthetic doses.

Research indicates that ketamine may promote neuroplasticity in brain networks associated with depression, although the exact mechanisms of its antidepressant effects are still not fully understood, as evidenced by a review of 51 studies using various neuroimaging techniques.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Neuroimaging-Derived Biomarkers of the Antidepressant Effects of Ketamine. Zavaliangos-Petropulu, A., Al-Sharif, NB., Taraku, B., et al.[2023]

Ketamine, used at subanesthetic doses, shows promise for rapidly treating treatment-resistant depression, which is a challenging form of major depressive disorder (MDD).

Neuroimaging studies highlight key brain areas affected by ketamine, such as the subgenual anterior cingulate cortex, and suggest that it may alter self-monitoring and enhance reward processing, although further research is needed to fully understand its antidepressant mechanism.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ketamine-Associated Brain Changes: A Review of the Neuroimaging Literature. Ionescu, DF., Felicione, JM., Gosai, A., et al.[2023]

Neuroimaging studies reveal that depression is linked to structural and functional abnormalities in specific brain regions, such as the frontal lobe, temporal lobe, and limbic system, which may help explain the psychological symptoms and behavioral deficits associated with the disorder.

Magnetic resonance imaging (MRI) could become a crucial tool for psychiatrists in diagnosing depression early and accurately, as well as in identifying tailored treatment targets to improve clinical outcomes for patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Brain structural and functional changes in patients with major depressive disorder: a literature review. Dai, L., Zhou, H., Xu, X., et al.[2020]

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